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  OUR COMMON INSECTS.

  [Illustration: AMERICAN SILK WORM (MALE).]




  OUR

  COMMON INSECTS.

  A POPULAR ACCOUNT OF THE INSECTS

  OF OUR

  Fields, Forests, Gardens and Houses.


  Illustrated with 4 Plates and 268 Woodcuts.

  BY

  A. S. PACKARD, JR.,

  Author of "A GUIDE TO THE STUDY OF INSECTS."

  SALEM.
  NATURALISTS' AGENCY.
  BOSTON: Estes & Lauriat. NEW YORK: Dodd & Mead.
  1873.

  Entered, according to Act of Congress, in the year 1878, by
  F. W. PUTNAM & CO.,
  in the Office of the Librarian of Congress at Washington.

  PRINTED AT
  THE SALEM PRESS,
  F. W. PUTNAM & CO.,
  Proprietors.




DEDICATION.

TO SAMUEL H. SCUDDER.


MY DEAR SCUDDER:--You and I were drawn together many years ago by a
common love for insects and their ways.

I dedicate this little volume of ephemeral essays to you in recognition
of your worth as a man and a scientist, and as a token of warm
friendship.

  Yours sincerely,

  A. S. PACKARD, JR.




PREFACE.


This little volume mainly consists of a reprint of a series of essays
which appeared in the "American Naturalist" (Vols. i-v, 1867-71). It is
hoped that their perusal may lead to a better acquaintance with the
habits and forms of our more common insects. The introduction was
written expressly for this book, as well as Chapter XIII, "Hints on the
Ancestry of Insects." The scientific reader may be drawn with greater
interest to this chapter than to any other portion of the book. In this
discussion of a perhaps abstruse and difficult theme, his indulgence is
sought for whatever imperfections or deficiencies may appear. Our
systems of classification may at least be tested by the application of
the theory of evolution. The natural system, if we mistake not, is the
genealogy of organized forms; when we can trace the latter, we establish
the former. Considering how much naturalists differ in their views as to
what is a natural classification, it is not strange that a genealogy of
animals or plants seems absurd to many. To another generation of
naturalists it must, perhaps, be left to decide whether to attempt the
one is more unphilosophical than to attempt the other.

Most of the cuts have already appeared in the "Guide to the Study of
Insects" and the "American Naturalist," where their original sources are
given, while a few have been kindly contributed by Prof. A. E. Verrill,
the Boston Society of Natural History, and Prof. C. V. Riley, and three
are original.

SALEM, June, 1873.




OUR COMMON INSECTS.

INTRODUCTORY.


_What is an Insect?_ When we remember that the insects alone comprise
four-fifths of the animal kingdom, and that there are upwards of 200,000
living species, it would seem a hopeless task to define what an insect
is. But a common plan pervades the structure of them all. The bodies of
all insects consist of a succession of rings, or segments, more or less
hardened by the deposition of a chemical substance called chitine; these
rings are arranged in three groups: the head, the thorax, or middle
body, and the abdomen or hind body. In the six-footed insects, such as
the bee, moth, beetle or dragon fly, four of these rings unite early in
embryonic life to form the head; the thorax consists of three, as may be
readily seen on slight examination, and the abdomen is composed either
of ten or eleven rings. The body, then, seems divided or _insected_ into
three regions, whence the name _insect_.

The head is furnished with a pair of antennæ, a pair of jaws
(mandibles), and two pairs of maxillæ, the second and basal pair being
united at their base to form the so-called labium, or under lip. These
four pairs of appendages represent the four rings of the head, to which
they are appended in the order stated above.

A pair of legs is appended to each of the three rings of the thorax;
while the first and second rings each usually carry a pair of wings.

The abdomen contains the ovipositor; sometimes, as in the bees and
wasps, forming a sting. In the spiders (Fig. 1), however, there are no
antennæ, and the second maxillæ, or labium, is wanting. Moreover, there
are four pairs of legs. The centipedes (Fig. 2, a Myriopod) also differ
from the rest of the insects in having an indefinite number of abdominal
rings, each bearing a pair of legs.

[Illustration: 1. Spider (Tegenaria).]

On examining the arrangement of the parts within, we find the nervous
cord, consisting of two chains of swellings, or nerve-knots, resting
upon the floor or under side of the body; and the heart, or dorsal
vessel, situated just under the skin of the back; and in looking at
living caterpillars, such as the cut-worm, and many thin-skinned aquatic
larvæ, we can see this long tubular heart pulsating about as often as
our own heart, and when the insect is held against its will, or is
agitated, the rapidity of the pulsations increases just as with us.

[Illustration: 2. Centipede.]

Insects do not breathe as in the higher animals by taking the air into
the mouth and filling the lungs, but there are a series of holes or
pores along the side of the body, as seen in the grub of the humble bee,
through which the air enters and is conveyed to every part of the body
by an immense number of air tubes. (Fig. 3, air tubes, or tracheæ, in
the caudal appendage of the larva of a dragon fly). These air tubes are
everywhere bathed by the blood, by which the latter becomes oxygenated.

[Illustration: 3. Caudal appendage of larva of Agrion.]

Indeed the structure of an insect is entirely different from that of man
or the quadrupeds, or any other vertebrate animal, and what we call
head, thorax, abdomen, gills, stomach, skin, or lungs, or jaws, are
called so simply for convenience, and not that they are made in the same
way as those parts in the higher animals.

An insect differs from a horse, for example, as much as a modern
printing press differs from the press Franklin used. Both machines are
made of iron, steel, wood, etc., and both print; but the plan of their
structure differs throughout, and some parts are wanting in the simpler
press which are present and absolutely essential in the other. So with
the two sorts of animals; they are built up originally out of
protoplasm, or the original jelly-like germinal matter, which fills the
cells composing their tissues, and nearly the same chemical elements
occur in both, but the mode in which these are combined, the arrangement
of their products: the muscular, nervous and skin tissues, differ in the
two animals. The plan of structure, namely, the form and arrangement of
the body walls, the situation of the appendages to the body, and of the
anatomical systems within, i.e., the nervous, digestive, circulatory,
and respiratory systems, differ in their position in relation to the
walls of the body. Thus while the two sorts of animals reproduce their
kind, eat, drink and sleep, see, hear and smell, they perform these acts
by different kinds of organs, situated sometimes on the most opposite
parts of the body, so that there is no comparison save in the results
which they accomplish; they only agree in being animals, and in having a
common animal nature.

[Illustration: 4. Different forms of jaws.]

[Illustration: 5. Mouth parts of the Larva of a Beetle.]

[Illustration: 6. Maxilla of a Beetle.]

_How Insects Eat._ The jaws of insects (Fig. 4) are horny processes
situated on each side of the mouth. They are variously toothed, so as to
tear the food, and move horizontally instead of up and down as in the
horse. The act of taking the food, especially if the insect be
carnivorous in its habits, is quite complex, as not only the true jaws,
but the accessory jaws (maxillæ, Fig. 5, _a_, upper, b, under side of
the head of a young beetle; _at_, antennæ, _md_, mandible, _mx_,
maxillæ, _mx_[1], labium) and the feelers (palpi) attached to the
maxillæ, and the under lip (labium) are of great service in enabling the
insect to detect its food both by the senses of touch and smell. The
maxillæ are in the fully grown beetle (Fig. 6) divided into three lobes,
the outermost forming the palpus, and the two others forming sharp
teeth, often provided with hairs and minute brushes for cleansing the
adjoining parts; these strong curved teeth are used in seizing the food
and placing it between the grinders, where it is crushed, prepared for
digestion and swallowed. Fig. 7 represents the mouth parts of the humble
bee. (_b_, upper lip; _d_, mandible; _e_, maxilla; _f_, maxillary
palpus; _g_, tongue; _ih_, labium and tabial palpi; _k_, eye.)

[Illustration: 7. Mouth parts of a Humble Bee.]

The alimentary canal passes through the middle of the body, the stomach
forming usually a simple enlargement. Just before the stomach in certain
insects, as the grasshopper, is a gizzard armed with rows of powerful
horny teeth for finely crushing grass.

Insects eat almost incredible quantities of food when young and growing
rapidly. Mr. Trouvelot tells us in the "American Naturalist" that the
food taken by a single American Silk-worm in fifty-six days is equal to
eighty-six thousand times its primitive weight! On the other hand, after
the insect has finished its transformations, it either takes no food at
all, as in the May fly, or merely sips the honey of flowers, as in the
butterfly, while the June beetle and many others like it eat the leaves
of trees, and the tiger and ground beetles feed voraciously on other
insects.

_How Insects Walk._ In man and his allies, the vertebrates, the process
of walking is a most difficult and apparently dangerous feat. To
describe the mechanics of walking, the wonderful adaptation of the
muscles and bones for the performance of this most ordinary action of
life, would require a volume. The process is scarcely less complex in
insects. Lyonnet found 3,993 muscles in a caterpillar, and while a large
proportion belong to the internal organs, over a thousand assist in
locomotion. Hence the muscular power of insects is enormous. A flea will
leap two hundred times its own height, and certain large, solid beetles
will move enormous weights as compared to the bulk of their bodies.

[Illustration: 8. Larva of a beetle (Photuris).]

In walking, as seen in the accompanying figure (Fig. 8), three legs are
thrown forward at a time, two on one side and one on the other.

Flies and many other insects can walk upside down, or on glass, as
easily as on a level surface. A fly's foot, as in most other insects,
consists of five joints (tarsal joints), to the last one of which is
appended a pair of stout claws, beneath which is a flat, soft, fleshy
cushion or pad, split into two (sometimes three) flaps, beset on the
under surface with fine hairs. A part of these hairs are swollen at the
end, which is covered with "an elastic membranous expansion, capable of
close contact with a highly polished surface, from which a minute
quantity of a clear, transparent fluid is emitted when the fly is
actively moving." (T. West.) These hairs are hence called holding, or
tenent, hairs. With the aid of these, but mainly, as Mr. West insists,
by the pressure of the atmosphere, a fly is enabled to adhere to
perfectly smooth surfaces. His studies show the following curious facts.
"That atmospheric pressure, if the area of the flaps be alone
considered, is equal to just one-half the weight of a fly. If the area
covered by the tenent hairs be added, an increase of pressure is gained,
equal to about one-fourth the weight of a fly. This leaves one-fourth to
be accounted for by slight viscidity of the fluid, by the action I have
so often alluded to, which may be called 'grasping,' by molecular
attraction, and, doubtless, by other agents still more subtle, with
which we have at present scarcely any acquaintance."

_How Insects Fly._ Who of us, as remarked by an eminent ornithologist,
can even now explain the long sustained, peculiar flight of the hawk, or
turkey buzzard, as it sails in the air without changing the position of
its wings? and, we would add, the somewhat similar flight of a
butterfly? It is the poetry of motion, and a marvellous exhibition of
grace and ease, combined with a wonderful underlying strength and
lightness of the parts concerned in flight.

Before we give a partial account of the results obtained by the delicate
experiments of Professor Marey on the flight of birds and insects, our
readers should be reminded of the great differences between an insect
and a bird, remembering that the former, is, in brief, a chitinous sac,
so to speak, or rather a series of three such spherical or elliptical
sacs (the head, thorax and abdomen); the outer walls of the body forming
a solid but light crust, to which are attached broad, membranous wings,
the wing being a sort of membranous bag stretched over a framework of
hollow tubes (the tracheæ), so disposed as to give the greatest
lightness and strength to the wing. The wings are moved by powerful
muscles of flight, filling up the cavity of the thorax, just as the
muscles are the largest about the thorax of a bird. Moreover in the
bodies of insects that fly (such as the bee, cockchafer, and dragon
fly), as distinguished from those that creep exclusively, the air tubes
(tracheæ) which ramify into every part of the body, are dilated here and
there, especially in the base of the abdomen, into large sacs, which are
filled with air when the insect is about to take flight, so that the
specific gravity of the body is greatly diminished. Indeed, these air
sacs, dilatable at will by the insect, may be compared to the swimming
bladder of fishes, which enables them to rise and fall at will to
different levels in the sea, thus effecting an immense saving of the
labor of swimming. In the birds, as every body knows who has eaten a
chicken, or attended the dissection of a Thanksgiving turkey, the soft
parts are external, attached to the bony framework comprising the
skeleton, the wing bones being directly connected with the central back
bone; so that while these two sorts of animated flying machines are so
different in structure, they yet act in much the same manner when on the
wing. The difference between them is clearly stated by Marey, some of
whose conclusions we now give almost word for word.

The flight of butterflies and moths differs from that of birds in the
almost vertical direction of the stroke of their wings, and in their
faculty of sailing in the air without making any movements; though
sometimes in the course they pursue they seem to resemble birds in their
flight.

The flight of insects and birds moreover differs in the form of the
trajectory in space; in the inclination of the plane in which the wings
beat; in the role of each of the two alternating (and in an inverse
sense) movements that the wings execute; as also in the facility with
which the air is decomposed during these different movements. As the
wings of a fly are adorned with a brilliant array of colors, we can
follow the trajectory or figure that each wing writes in the air. It is
of the form of a figure of eight (Fig. 9), first discovered by Professor
J. Bell Pettigrew of Edinburgh.

[Illustration: 9. Figure cut by an insect's wing.]

[Illustration: 10. Figure cut by a bird's wing.]

By an ingenious machine, specially devised for the purpose, Professor
Marey found that a bird's wing moves in an ellipse, with a pointed
summit (Fig. 10). The insect beats the air in a distinctly horizontal
plane, but the bird in a vertical plane. The wing of an insect is
impervious to the air; while the bird's wing resists the air only on
its under side. Hence, there are two sorts of effects; in the insect
the up and down strokes are active; in the bird, the lowering of the
wing is the only active period, though the return stroke seems to
sustain the bird, the air acting on the wing. The bird's body is
horizontal when the wing gives a downward stroke; but when the beat is
upward, the bird is placed in an inclined plane like a winged
projectile, and mounts up on the air by means of the inclined surfaces
that it passively offers to the resistance of this fluid.

[Illustration: 11. Trajectory of an insect's wing.]

[Illustration: 12. Trajectory of a bird's wing.]

In an insect, an energetic movement is equally necessary to strike the
air at both beats up and down. In the bird, on the contrary, one active
beat only is necessary, the down beat. It creates at that time all the
motive force that will be dispensed during the entire revolution of the
wing. This difference is due to the difference in form of the wing. The
difference between the two forms of flight is shown by an inspection of
the two accompanying figures (11, 12). An insect's wing is small at the
base and broad at the end. This breadth would be useless near the body,
because at this point the wing does not move swiftly enough to strike
the air effectively. The type of the insectean wing is designed, then,
simply to strike the air. But in the bird the wing plays also a passive
role, _i. e._, it receives the pressure of the air on its under side
when the bird is projected rapidly onward by its acquired swiftness. In
these conditions the whole animal is carried onward in space; all the
points of its wing have the same velocity. The neighboring regions of
the body are useful to press upon the air, which acts as on a paper
kite. The base of the wing also, in the bird, is broad, and provided
with feathers, which form a broad surface, on which the air presses with
a force and method very efficacious in supporting the bird. Fig. 12
gives an idea of this disposition of the wing at the active and passive
time in a bird.

The inner half of the wing is the passive part of the organ, while the
external half, that which strikes the air, is the active part. A fly's
wing makes 330 revolutions in a second, executing consequently 660
simple oscillations; it ought at each time to impress a lateral
deviation of the body of the insect, and destroy the velocity that the
preceding oscillation has given it in a contrary direction. So that by
this hypothesis the insect in its flight only utilizes fifty to one
hundred parts (or one-half) of the resistance that the air furnishes it.

[Illustration: 13. A bird on the wing.]

In the bird (Fig. 13), at the time of lowering the wings, the oblique
plane which strikes the air, in decomposing the resistance, produces a
vertical component which resists the weight of the body, and a
horizontal component which imparts swiftness. The horizontal component
is not lost, but is utilized during the rise of the wing, as in a paper
kite when held in the air against the wind. Thus the bird utilizes
seventy-five out of one hundred parts of the resistance that the air
furnishes. The style of flight of birds is, therefore, theoretically
superior to that of insects. As to the division of the muscular force
between the resistance of the air and the mass of the body of the bird,
we should compare the exertion made in walking on sand, for example, as
compared with walking on marble. This is easy to measure. When a fish
strikes the water with its tail to propel itself forward, it performs a
double task; one part consists in pushing backwards a certain mass of
water with a certain swiftness, and the other in pushing on the body in
spite of the resistance of the surrounding fluid. This last portion of
the task only is utilized. It would be greater if the tail of the fish
encountered a solid object. Almost all the propelling agencies employed
in navigation undergo this loss of labor, which depends on the mobility
of the _point d' appui_. The bird is placed among conditions especially
unfavorable.

_The Senses of Insects._ The eyes of insects are sometimes so large as
to envelop the head like an Elizabethan ruffle, and the creature's head,
as in the common house fly, seems all eyes. And this is almost literally
the case, as the two great staring eyes that almost meet on the top of
the head to form one, are made up of myriads of simple eyes. Each facet
or simple eye is provided with a nerve filament which branches off from
the main optic nerve, so that but one impression of the object perceived
is conveyed to the brain; though it is taught by some that objects
appear not only double but a thousand times multiplied. But we should
remember that with our two eyes we see double only when the brain is
diseased. Besides the large ordinary compound eyes, many insects possess
small, simple eyes, like those of the spider. The great German
anatomist, Johannes Müller, believed that the compound eyes were adapted
for the perception of distant objects, while those nearer are seen by
the simple eyes. But it may be objected to this view that the spiders,
which have only simple eyes, apparently see both near and remote objects
as well as insects.

The sense of touch is diffused all over the body. As in the hairs of the
head and face of man, those of insects are delicate tactile organs; and
on the antennæ and legs (insects depending on this sense rather than
that of sight) these appendages are covered with exquisitely fine
hairs. It is thought by some that the senses of hearing and smell are
lodged in the antennæ, these organs thus combining the sense of feeling
with those of hearing and smelling. And the researches of anatomists
lend much probability to the assertion, since little pits just under the
skin are found, and even sometimes provided with grains of sand in the
so-called ear of the lobster, etc., corresponding to the ear bones of
the higher animals, the pits being connected with nerves leading to the
brain. We have detected similar pits in the under side of the palpi of
the Perla. It seems not improbable that these are organs of smell, and
placed in that part of the appendage nearest the mouth, so as to enable
the insect to select its proper food by its odor. Similar organs exist
on the caudal appendages of a kind of fly (Chrysopila), while the long,
many-jointed caudal filaments of the cockroach are each provided with
nearly a hundred of these little pits, which seem to be so many noses.
Thus Lespès, a Swiss anatomist, in his remarks on the auditory sacs,
which he says are found in the antennæ of nearly all insects, declares
that as we have in insects compound eyes, so we have compound ears. We
might add that in the abdominal appendage of the cockroach we have a
compound nose, while in the feelers of the Perla, and the caudal
appendage of the Chrysopila, the "nose" is simple. We might also refer
here to Siebold's discovery of ears at the base of the abdomen of some,
and in the forelegs of other kinds, of grasshoppers. Thus we need not be
surprised at finding ears and noses scattered, as it were, sometimes
almost wantonly over the bodies of insects (in many worms the eyes are
found all over the body), while in man and his allies, from the monkey
down to the fish, the ears and nose invariably retain the same relative
place in the head.

_How Insects Grow._ When beginning our entomological studies no fact
seemed more astonishing to our boyish mind than the thought that the
little flies and midges were not the sons and daughters of the big
ones. If every farmer and gardener knew this single fact it would be
worth their while. The words _larva_ and _pupa_ will frequently occur in
subsequent pages, and they should be explained. The caterpillar (Fig.
14, _a_) represents the earliest stage or babyhood of the butterfly, and
it is called _larva_, from the Latin, meaning a mask, because it was
thought by the ancients to mask the form of the adult butterfly.

[Illustration: 14. _a_ Larva, _b_ chrysalis of a butterfly.]

When the caterpillar has ended its riotous life, for its appetite almost
transforms its being into the very incarnation of gluttony, it suddenly,
as if repenting of its former life as a _bon vivant_, seeks a solitary
cell or hole where like a hermit it sits and leads apparently about as
useless an existence. But meanwhile strange processes are going on
beneath the skin; and after a few convulsive struggles the back splits
open, and out wriggles the chrysalis, a gorgeous, mummy-like form, its
body adorned with golden and silvery spots. Hence the word chrysalis
(Fig. 14, _b_), from the Greek, meaning golden, while the Latin word
_pupa_, meaning a baby or doll, is indicative of its youth. In this
state it hangs suspended to a twig or other object; while the silk worm,
and others of its kind, previous to moulting, or casting their skins,
spin a silken cocoon, which envelops and protects the chrysalis.

[Illustration: 15. Imago or adult Butterfly.]

At the given time, and after the body of the adult has fully formed
beneath the chrysalis skin, there is another moult, and the butterfly,
with baggy, wet wings, creeps out. The body dries, the skin hardens, the
wings expand, and in a few moments, sometimes an hour, the butterfly
(Fig. 15) proudly sails aloft, the glory and pride of the insect world.

We shall see in the ensuing chapters how varied are the larvæ and pupæ
of insects, and under what different guises insects live in their early
stages.

[Illustration: Larva, pupa, and adult of a Leaf Beetle (Galeruca).]




OUR COMMON INSECTS.




CHAPTER I.

THE HOME OF THE BEES.


The history of the Honey bee, its wonderful instincts, its elaborate
cells and complex economy, have engrossed the attention of the best
observers, even from the time of Virgil, who sang of the Ligurian bee.
The literature of the art of bee-keeping is already very extensive.
Numerous bee journals and manuals of bee-keeping testify to the
importance of this art, while able mathematicians have studied the mode
of formation of the hexagonal cells,[1] and physiologists have
investigated the intricate problems of the mode of generation and
development of the bee itself.

In discussing these difficult questions, we must rise from the study of
the simple to the complex, remembering that--

  "All nature widens upward. Evermore
  The simpler essence lower lies:
  More complex is more perfect--owning more
  Discourse, more widely wise."

and not forget to study the humbler allies of the Honey bee. We shall,
in observing the habits and homes of the wild bees, gain a clearer
insight into the mysteries of the hive.

The great family of bees is divided into social and solitary species.
The social kinds live in nests composed of numerous cells in which the
young brood are reared. These cells vary in form from those which are
quite regularly hexagonal, like those of the Hive bee, to those which
are less regularly six-sided, as in the stingless bee of the tropics
(Melipona), until in the Humble bee the cells are isolated and
cylindrical in form.

Before speaking of the wild bees, let us briefly review the life of the
Honey bee. The queen bee having wintered over with many workers, lays
her eggs in the spring, first in the worker, and, at a later period, in
the drone-cells. Early in the summer the workers construct the large,
flask-shaped queen-cells, which are placed on the edge of the comb, and
in these the queen larvæ are fed with rich and choice food. The old
queen deserts the nest, forming a new colony. The new-born queen takes
her marriage flight high in the air with a drone, and on her return
undertakes the management of the hive, and the duty of laying eggs. When
the supply of queens is exhausted, the workers destroy the drones. The
first brood of workers live about six weeks in summer, and then give way
to a new brood. The queens, according to Von Berlepsch, are known to
live five years, and during their whole life lay more than a million
eggs.

In the tropics, the Honey bee is replaced by the Meliponas and Trigonas.
They are minute, stingless bees, which store up honey and live in
colonies often of immense extent. The cells of Melipona are hexagonal,
nearly approaching in regularity those of the Hive bee, while the honey
cells are irregular, being much larger cavities, which hold about
one-half as much honey as a cell of the Humble bee. "Gardner, in his
travels, states that many species of Melipona build in the hollow trunks
of trees, others in banks; some suspend their nests from the branches of
trees, whilst one species constructs its nest of clay, it being of large
size." (F. Smith.)

In a nest of the coal-black Trigona (Trigona carbonaria), from eastern
Australia, Mr. F. Smith, of the British Museum, found from four hundred
to five hundred dead workers, but no females. The combs were arranged
precisely similar to those of the common wasp. The number of honey-pots
which were placed at the foot of the nest was two hundred and fifty. Mr.
Smith inclines to the opinion that the hive of Trigona contains several
prolific females, as the great number of workers can only be thus
explained, and M. Guérin found six females in a nest of the Tawny-footed
Melipona (M. fulvipes).

At home, our nearest ally of the true Honey bee, is the Humble bee
(Bombus), of which over forty species are known to inhabit North
America.

The economy of the Humble bee is thus: the queen awakens in early spring
from her winter's sleep under leaves or moss, or in the last year's
nest, and selects a nesting place, generally in an abandoned nest of a
field-mouse, or beneath a stump or sod, and "immediately," according to
Mr. F. W. Putnam,[2] "collects" a small amount of pollen mixed with
honey, and in this deposits from seven to fourteen eggs, gradually
adding to the pollen mass until the first brood is hatched. She does not
wait, however, for one brood to be hatched before laying the eggs of
another, but, as soon as food enough has been collected, she lays the
eggs for a second. The eggs are laid, in contact with each other, in one
cavity of the mass of pollen, with a part of which they are slightly
covered. They are very soon developed; in fact, the lines are nowhere
distinctly drawn between the egg and the larva, the larva and pupa, and
again between the latter and the imago; a perfect series, showing this
gradual transformation of the young to the imago can be found in almost
every nest.

[Illustration: 15. Cell and Eggs of Bombus.]

"As soon as the larvæ are capable of motion and commence feeding, they
eat the pollen by which they are surrounded, and, gradually separating,
push their way in various directions. Eating as they move, and
increasing in size quite rapidly, they soon make large cavities in the
pollen mass. When they have attained their full size, they spin a silken
wall about them, which is strengthened by the old bees covering it with
a thin layer of wax, which soon becomes hard and tough, thus forming a
cell (Fig. 15, 1, cell containing a larva, on top of which (2) is a
pollen mass containing three eggs). The larvæ now gradually attain the
pupa stage, and remain inactive until their full development. They then
cut their way out, and are ready to assume their duties as workers,
small females, males or queens.

"It is apparent that the irregular disposition of the cells is due to
their being constructed so peculiarly by the larvæ. After the first
brood, composed of workers, has come forth, the queen bee devotes her
time principally to her duties at home, the workers supplying the colony
with honey and pollen. As the queen continues prolific, more workers are
added, and the nest is rapidly enlarged.

"About the middle of summer, eggs are deposited, which produce both
small females and males." ... "All eggs laid after the last of July
produce the large females, or queens, and, the males being still in the
nest, it is presumed that the queens are impregnated at this time, as on
the approach of cold weather all except the queens, of which there are
several in each nest, die."

While the Humble bee in some respects shows much less instinct than the
solitary bees mentioned below, it stands higher in the series, however,
from having workers, as well as males and females, who provide food for
the young. The labors of the Mason bees, and their allies, terminate
after the cell is once constructed and filled with pollen. The eggs are
then left to hatch, and the young care for themselves, though the adult
bee shows greater skill in architecture than the Humble bee. It is thus
throughout nature. Many forms, comparatively low in the scale of life,
astonish us with certain characters or traits, reminding us of beings
much superior, physically and intellectually. The lower forms constantly
reach up and in some way ally themselves with creatures far more highly
organized. Thus the fish-like seal reminds us strikingly of the dog,
both in the form of the head, in its docility and great intelligence
when tamed, and even in its bark and the movements of the head.

[Illustration: 16. Meloë.]

The parasites of the Humble bee are numerous. Such are the species of
Apathus, which so closely resembles the Humble bee itself, that it
requires long study to distinguish it readily. Its habits are not known,
other than that it is found in the nests of its host. It differs from
the Humble bee in having no pollen-basket, showing that its larvæ must
feed on the food stored up by their host, as it does not itself collect
it. The mandibles also are not, like those of Bombus, trowel-shaped for
architectural purposes, but acutely triangular, and are probably not
used in building.

The caterpillars of various moths consume the honey and waxen cells; the
two-winged flies, Volucella and Conops, and the larvæ of what is either
an Anthomyia or Tachina-like fly, and several species of another genus
of flies, Anthrax, together with several beetles, such as the Meloë
(Fig. 16), Stylops (Fig. 17, male; 18_b_, female; _a_, position in the
body of its host), and Antherophagus prey upon them.

[Illustration: 17. Male Stylops.]

The power of boring the most symmetrical tunnels in solid wood reaches
its perfection in the large Virginian Carpenter bee (Xylocopa Virginica,
Fig. 19). This bee is as large as, and some allied exotic species are
often considerably larger than, the Humble bee, but not clothed with
such dense hairs. We have received from Mr. James Angus, of West Farms,
N. Y., a piece of trellis from a grape vine, made of pine wood,
containing the cells and young in various stages of growth, together
with the larvæ and chrysalids of Anthrax sinuosa (Fig. 20), a species of
fly parasitic on the larva. The maggot buries its head in the soft body
of the young bee and feeds on its juices.

Mr. Angus thus writes us regarding its habits, under date of July 19: "I
asked an intelligent and observing carpenter yesterday, if he knew how
long it took the Xylocopa to bore her tunnel. He said he thought she
bored about one-quarter of an inch a day. I don't think myself she
bores more than one-half inch, if she does that. If I mistake not, it
takes her about two days to make her own length at the first start; but
this being across the grain of the wood, may not be so easily done as
the remainder, which runs parallel with it. She always follows the grain
of the wood, with the exception of the entrance, which is about her own
length. The tunnels run from one to one and a half feet in length. They
generally run in opposite directions from the opening, and sometimes
other galleries are run, one directly above the other, using the same
opening. I think they only make new tunnels when old ones are not to be
found, and that the same tunnels are used for many years. Some of the
old tunnels are very wide. I have found parts of them about an inch in
diameter. I think this is caused by rasping off the sides to procure the
necessary material for constructing their cells. The partitions are
composed of wood raspings, and some sticky fluid, probably saliva, to
make them adhere.

[Illustration: 18. Female Stylops.]

[Illustration: 19. Carpenter Bee.]

"The tunnels are sometimes taken possession of by other bees and wasps.
I think when this is the case, the Xylocopa prefers making a new cell,
to cleaning out the dirt and rubbish of the other species. I frequently
find these bees remaining for a long time on the wing close to the
opening, and bobbing their heads against the side, as if fanning air
into the opening. I have seen them thus employed for twenty minutes.
Whether one bee or more makes the tunnel, that is, whether they take
turns in boring, I cannot at present say. In opening the cells (Fig.
21), more than one are generally found, even at this season. About two
weeks ago; I found as many as seven, I think, in one."[3]

The hole is divided by partitions into cells about seven-tenths of an
inch long. These partitions are constructed of the coarse dust or
chippings made by the bee in eating out her cells, for our active little
carpenter is provided with strong cutting jaws, moved by powerful
muscles, and on her legs are stiff brushes of hair for cleaning out the
tunnel as she descends into the heart of the solid wood. She must throw
out the chips she bites off with her powerful mandibles from the sides
of the burrow, by means of her hind legs, passing the load of chips
backwards out of the cell with her fore limbs, which she uses as hands.

[Illustration: 20. Larva and Pupa of Anthrax.]

The partitions are built most elaborately of a single flattened band of
chips, which is rolled up into a coil four layers deep. One side,
forming the bottom of the cell, is concave, being beaten down and
smoothed off by the bee. The other side of the partition, forming the
top of the cell, is flat and rough.

[Illustration: 21. Nest of Carpenter Bee.]

At the time of opening the burrow, July 8th, the cells contained nearly
full-grown larvæ, with some half developed. They were feeding on the
masses of pollen, which were as large as a thick kidney bean, and
occupied nearly half the cell. The larvæ (Fig. 21) resemble those of the
Humble bee, but are slenderer, tapering more rapidly towards each end of
the body.

The habits and structure of the little green Ceratina ally it closely
with Xylocopa. This pretty bee, named Ceratina dupla by Mr. Say, tunnels
out the stems of the elder or blackberry, syringa, or any pithy shrub,
excavating them often to a depth of six or seven inches. She makes the
walls just wide enough to admit her body, and of a depth capable of
holding three or four, often five or six cells (Fig. 22). The finely
built cells, with their delicate silken walls, are cylindrical and
nearly square at each end, though the free end of the last cell is
rounded off. They are four and a half tenths of an inch long, and a
little over one-third as broad. The bee places them at nearly equal
distances apart, the slight interval between them being filled in with
dirt.

[Illustration: 22. Nest of Ceratina.]

Dr. T. W. Harris states that May 15, 1832, one female laid its eggs in
the hollow of an aster stalk. Three perfect insects were disclosed from
it July 28th. The observations of Mr. Angus, who saw some bees making
their cells May 18th, also confirm this account. The history of our
little upholsterer is thus cleared up. Late in the spring she builds her
cells, fills them with pollen, and lays one or more eggs upon each mass.
Thus in about two months the insect completes its transformations;
within this period passing through the egg, the larva and chrysalid
states, and then, as a bee, living a few days more, if a male; or if a
female, living through the winter. Her life thus spans one year.

The larva (Fig. 23) is longer than that of Megachile, and compared with
that of Xylocopa, the different segments are much more convex, giving a
serrate outline to the back of the worm. The pupa, or chrysalis, we have
found in the cells the last of July. It is white, and three-tenths of an
inch long. It differs from that of the Leaf-cutter bee in having four
spines on the end of the body.

[Illustration: 23. Larva of Ceratina.]

[Illustration: 24. Nest of Tailor Bee.]

In none of the wild bees are the cells constructed with more nicety than
those of our little Ceratina. She bores out with her jaws a long deep
well just the size of her body, and then stretches a thin, delicate
cloth of silk drawn tight as a drum-head across each end of her
chambers, which she then fills with a mixture of pollen and honey.

[Illustration: 25. Tailor Bee.]

Her young are not, in this supposed retreat, entirely free from danger.
The most invidious foes enter and attack the brood. Three species of
Ichneumon flies, two of which belong to the Chalcid family, lay their
eggs within the body of the larva, and emerge from the dried larva and
pupa skins of the bee, often in great numbers. The smallest parasite,
belonging to the genus Anthophorabia, so called from being first known
as a parasite on another bee (Anthophora), is a minute species found
also abundantly in the tight cells of the Leaf-cutter bee.

The interesting habits of the Leaf-cutting, or Tailor bee (Megachile),
have always attracted attention. This bee is a stout, thick-bodied
insect, with a large, square head, stout, sharp, scissors-like jaws, and
with a thick mass of stout, dense hairs on the under side of the tail
for carrying pollen, as she is not provided with the pollen-basket of
the Honey and Humble bees.

The Megachile lays its eggs in burrows in the stems of the elder (Fig.
24), which we have received from Mr. James Angus; we have also found
them in the hollows of the locust tree. Mr. F. W. Putnam thus speaks of
the economy of M. centuncularis, our most common species. "My attention
was first called, on the 26th of June, to a female busily engaged in
bringing pieces of leaf to her cells, which she was building under a
board, on the roof of the piazza, directly under my window. Nearly the
whole morning was occupied by the bee in bringing pieces of leaf from a
rose bush growing about ten yards from her cells, returning at intervals
of a half minute to a minute with the pieces, which she carried in such
a manner as not to impede her steps when she alighted near her hole."
When the Leaf-cutter bee wishes to cut out a piece of a leaf (Fig. 25)
she alights upon the leaf, and in a few seconds swiftly runs her
scissors-like jaws around through it, bearing off the piece in her hind
legs. "About noon she had probably completed the cell, upon which she
had been engaged, as, during the afternoon, she was occupied in bringing
pollen, preparatory to laying her single egg in the cell. For about
twenty days the bee continued at work, building new cells and supplying
them with pollen.... On the 28th of July, upon removing the board, it
was found that the bee had made thirty cells, arranged in nine rows of
unequal length, some being slightly curved to adapt them to the space
under the board. The longest row contained six cells, and was two and,
three-quarters inches in length; the whole leaf structure being equal to
a length of fifteen inches. Upon making an estimate of the pieces of
leaf in this structure, it was ascertained that there must have been at
least a thousand pieces used. In addition to the labor of making the
cells, this bee, unassisted in all her duties, had to collect the
requisite amount of pollen (and honey?) for each cell, and lay her eggs
therein, when completed. Upon carefully cutting out a portion of one of
the cells, a full-grown larva was seen engaged in spinning a slight
silken cocoon about the walls of its prison, which were quite hard and
smooth on the inside, probably owing to the movements of the larva, and
the consequent pressing of the sticky particles to the walls. In a short
time the opening made was closed over by a very thin silken web. The
cells, measured on the inside of the hard walls, were .35 of an inch in
length, and .15 in diameter. The natural attitude of the larva is
somewhat curved in its cell, but if straightened, it just equals the
inside length of the cell. On the 31st of July, two female bees came
out, having cut their way through the sides of their cells." In three
other cells "several hundred minute Ichneumons (Anthophorabia
megachilis) were seen, which came forth as soon as the cells were
opened."

The habits of the little blue or green Mason bees (Osmia) are quite
varied. They construct their cells in the stems of plants, and in rotten
posts and trees, or, like Andrena, they burrow in sunny banks. A
European species selects snail shells for its nest, wherein it builds
its earthen cells, while other species nidificate under stones. Curtis
found two hundred and thirty cocoons of a British species (Osmia
paretina), placed on the under side of a flat stone, of which one-third
were empty. Of the remainder, the most appeared between March and June,
males appearing first; thirty-five more bees were developed the
following spring. Thus there were three successive broods, for three
succeeding years, so that these bees lived three years before arriving
at maturity. This may partly account for _insect years_, which are like
"apple years," seasons when bees and wasps, as well as other insects,
abound in unusual numbers.

[Illustration: 26. Nest of Osmia.]

Mr. G. R. Waterhouse, in the Transactions of the Entomological Society
of London, for 1864, states that the cells of Osmia leucomelana "are
formed of mud, and each cell is built separately. The female bee,
having deposited a small pellet of mud in a sheltered spot between some
tufts of grass, immediately begins to excavate a small cavity in its
upper surface, scraping the mud away from the centre towards the margin
by means of her jaws. A small, shallow mud-cup is thus produced. It is
rough and uneven on the outer surface, but beautifully smooth on the
inner. On witnessing thus much of the work performed, I was struck with
three points: first, the rapidity with which the insect worked;
secondly, the tenacity with which she kept her original position whilst
excavating; and thirdly, her constantly going over work which had
apparently been completed.... The lid is excavated and rendered concave
on its outer or upper surface, and is convex and rough on its inner
surface; and, in fact, is a simple repetition of the first-formed
portion of the cell, a part of a hollow sphere."

The largest species of Osmia known to us is a very dark-blue species (O.
lignivora). We are indebted to a lady for specimens of the bees with
their cells, which had been excavated in the interior of a maple tree
several inches from the bark. The bee had industriously tunnelled out
this elaborate burrow (Fig. 26), and, in this respect, resembled the
habits of the Carpenter bee more closely than any other species of its
genus.

The tunnel was over three inches long, and about three-tenths of an inch
wide. It contracted a little in width between the cell, showing that the
bee worked intelligently, and wasted no more of her energies than was
absolutely necessary. The burrow contained five cells, each half an inch
long, being rather short and broad, with the hinder end rounded, while
the opposite end, next to the one adjoining, is cut off squarely. The
cell is somewhat jug-shaped, owing to a slight constriction just behind
the mouth. The material of which the cell is composed is stout, silken,
parchment-like, and very smooth within. The interstices between the
cells are filled in with rather coarse chippings made by the bee.

The bee cut its way out of the cells in March, and lived for a month
afterwards on a diet of honey and water. It eagerly lapped up the drops
of water supplied by its keeper, to whom it soon grew accustomed, and
seemed to recognize.

Our smallest and most abundant species is the little green Osmia
simillima. It builds its little oval, somewhat urn-shaped cells against
the roof of the large deserted galls of the oak-gall fly (Diplolepis
confluentus), placing them, in this instance eleven in number, in two
irregular rows, from which the mature bees issue through a hole in the
gall (Fig. 27, with two separate cells). The earthen cells, containing
the tough dense cocoons, were arranged irregularly so as to fit the
concave vault of the larger gall, which was about two inches in
diameter. On emerging from the cell the Osmia cuts out with its powerful
jaws an ovate lid, nearly as large as one side of the cell.

[Illustration: 27. Nest of Osmia in a gall.]

In the Harris collection are the cells and specimens of Osmia pacifica,
the peaceful Osmia, which, according to the manuscript notes of Dr.
Harris, is found in the perfect state in earthen cells beneath stones.
The cell is oval cylindrical, a little contracted as usual with those of
all the species of the genus, thus forming an urn-shaped cell. It is
half an inch long, and nearly three-tenths of an inch wide, while the
cocoon, which is rather thin, is three-tenths of an inch long. We are
not acquainted with the habits of the larva and pupa in this country,
but Mr. F. Smith states that the larva of the English species hatches in
eight days after the eggs are laid, feeds ten to twelve days, when it
becomes full-grown, then spins a thin silken covering, and remains in an
inactive state until the following spring, when it completes its
transformations.

In the economy of our wild bees we see the manifestation of a wonderful
instinct, as well as the exhibition of a _limited reason_. We can
scarcely deny to animals a kind of reason which apparently differs _only
in degree_ from that of man. Each species works in a sphere limited by
physical laws, but within that sphere it is a free agent. They have
enough of instinct and reason to direct their lives, and to enable them
to act their part in carrying out the plan of creation.

[Illustration: Paper Wasp.]

FOOTNOTES:

[Footnote 1: The cells are not perfectly hexagonal. See the studies on
the formation of the cells of the bee, by Professor J. Wyman, in the
Proceedings of the American Academy of Arts and Sciences, Boston, 1866;
and the author's Guide to the Study of Insects, p 123.]

[Footnote 2: Notes on the Habits of the Humble Bee (Proceedings of the
Essex Institute, vol. iv, 1864, p. 101).

Mr. Angus also writes us as follows concerning the habits of the
Wandering Humble bee (Bombus vagans): "I have found the males plentiful
near our garden fence, within a hole such as would be made by a mouse.
They seem to be quite numerous. I was attracted to it by the noise they
were making in fanning at the opening. I counted at one time as many as
seven thus employed, and the sound could be heard several yards off.
Several males were at rest, but mostly on the wing, when they would make
a dash among the fanners, and all would scatter and play about. The
workers seem to be of a uniform size, and full as large as the males. I
think the object of the fanning was to introduce air into the nest, as
is done by the Honey bees."]

[Footnote 3: "Since writing the above I have opened one of the new holes
of Xylocopa, which was commenced between three and four weeks ago, in a
pine slat used in the staging of the greenhouse. The dimensions were as
follows:--Opening fully 3-8 wide; depth 7-16; whole length of tunnel 6
5-16 inches. The tunnel branched both ways from the hole. One end, from
opening, was 2 5-8, containing three cells, two with larva and pollen,
the third empty. The other side of the opening, or the rest of the
tunnel, was empty, with the exception of the old bee (only one) at work.
I think this was the work of one bee, and, as near as I can judge, about
twenty-five days' work. Width of tunnel inside at widest 9-16 inch.

"I have just found a Xylocopa bobbing at one of the holes, and in order
to ascertain the depth of the tunnel, and to see whether there were any
others in them, I sounded with a pliable rod, and found others in one
side, at a depth of five and one half inches; the other side was four
inches deep without bees. The morning was cool, so that the object in
bobbing could not have been to introduce fresh currents of air, but must
have had some relation to those inside. Their legs on such occasions
are, as I have noticed, loaded with pollen."]




CHAPTER II.

THE HOME OF THE BEES.

[_Concluded._]


While the Andrena and Halictus bees, whose habits we now describe, are
closely allied in form to the Hive bee, socially they are the
"mud-sills" of bee society, ranking among the lowest forms of the family
of bees. Their burrowing habits ally them with the ants, from whose
nests their own burrows can scarcely be distinguished. Their economy
does not seem to demand the exercise of so much of a true reasoning
power and pliable instinct as characterizes bees, such as the Honey and
Humble bee, which possess a high architectural skill. Moreover they are
not social; they have no part in rearing and caring for their young, a
fact that lends so much interest to the history of the Hive and Humble
bee. In this respect they are far below the wasps, a family belonging
next below in the system of Nature.

A glance at the drawing (Fig. 28), of a burrow, with its side galleries,
of the Andrena vicina, reveals the economy of one of our most common
forms. Quite early in spring, when the sun and vernal breezes have dried
up the soil, and the fields exchange their rusty hues for the rich green
verdure of May, our Andrena, tired of its idle life among the blossoms
of the willow, the wild cherry, and garden flowers, suddenly becomes
remarkably industrious, and wields its spade-like jaws and busy feet
with a strange and unwonted energy. Choosing some sunny, warm, grassy
bank (these nests were observed in the "great pasture" of Salem), not
always with a southern exposure however, the female sinks her deep well
through the sod from six inches to a foot into the sandy soil beneath.
She goes to work literally tooth and nail. Reasoning from observations
made on several species of wasps, and also from studying the structure
of her jaws and legs, it is evident that she digs in and loosens the
soil with her powerful jaws, and then throws out the dirt with her legs.
She uses her fore legs like hands, to pass the load of dirt to her hind
legs, and then runs backward out of her hole to dump it down behind her.
Mr. Emerton tells me that he never saw a bee in the act of digging but
once, and then she left off after a few strokes. He also says, "they are
harmless and inoffensive. On several occasions I have lain on the grass
near their holes for hours, but not one attempted to sting me; and when
taken between the fingers, they make but feeble resistance."

[Illustration: Fig. 28.

Nest (natural size) of Andrena vicina, showing the main burrow, and the
cells leading from it; the oldest cell containing the pupa (_a_) is
situated nearest the surface, while those containing the larva (_b_) lie
between the pupa and the cell (_e_) containing the pollen mass and egg
resting upon it. The most recent cell (_f_) is the deepest down, and
contains a freshly deposited pollen mass. At _c_ is the beginning of a
cell; _g_, level of the ground.]

To enter somewhat into detail, we gather from the observations of Mr.
Emerton (who has carefully watched the habits of these bees through
several seasons) the following account of the economy of this bee: On
the 4th of May the bees were seen digging their holes, most of which
were already two inches deep, and one, six inches. The mounds of earth
were so small as to be hardly noticed. At this time an Oil beetle was
seen prowling about the holes. The presence of this dire foe of Andrena
at this time, it will be seen in a succeeding chapter on the enemies of
the bees, is quite significant. By the 15th of May, hundreds of Andrena
holes were found in various parts of the pasture, and at one place, in a
previous season, there were about two hundred found placed within a
small area. One cell was dug up, but it contained no pollen. Four days
later, several Andrenas were noticed resting from their toil at the
opening of their burrows. On the 28th of May, in unearthing six holes,
eight cells were found to contain pollen, and in two of them a small
larva. The pellets of pollen are about the size of a small pea. They are
hard and round at first, before the young has hatched, but as the larva
grows, the mass becomes softer and more pasty, so that the larva buries
its head in the mass, and greedily sucks it in. When is the pollen
gathered by the bee and kneaded into the pellet-like mass? On July 4th,
a cell was opened in which was a bee busily engaged preparing the
pollen, which was loosely and irregularly piled up, while there was a
larva in an adjoining cell nearly half an inch long. It would seem,
then, that the bee comes in from the fields laden with her stores of
pollen, which she elaborates into bee bread within her cell.

When the bee returns to her cell she does not directly fly towards the
entrance, since, as was noticed in a particular instance, she flew about
for a long time in all directions without any apparent aim, until she
finally settled near the hole, and walked into her subterranean retreat.
On a rainy day, May 24th, our friend visited the colony, but found no
bees flying about the holes. The little hillocks had been beaten down by
the pitiless raindrops, and all traces of their industry effaced. On
digging down, several bees were found, indicating that on rainy days
they seek the shelter of their holes, and do not take refuge under
leaves of the plants they frequent.

On the 29th of June, six full-grown larvæ were exhumed, and one, about
half grown. On the 20th of July, the colony seemed well organized, as,
on laying open a burrow at the depth of six inches, he began to find
cells. The upper ones, to the number of a dozen, were deserted and
filled with earth and grass roots, and had evidently been built and used
during the previous year. Below these were eight cells placed around the
main vertical gallery, reaching down to the depth of thirteen inches,
and all containing nearly full-grown larvæ of the bees, or else those of
some parasitic bee (Nomada) which had devoured the food prepared for the
young Andrena.

About the first of August the larva transforms to a pupa or chrysalis,
as at this time two pupæ were found in cells a foot beneath the surface.
As shown in the cut, those cells situated lowest down seem to be the
last to have been made, while the eggs laid in the highest are the first
to hatch, and the larvæ disclosed from them, the first to change to
pupæ. Four days later the pupæ of Cuckoo bees (Nomada) were found in the
cells. No Andrenas were seen flying about at this time.

On the 24th of August, to be still very circumstantial in our narrative
though at the risk of being tedious, three burrows were unearthed, and
in them three fully formed bees were found nearly ready to leave their
cells, and in addition several pupæ. In some other cells there were
three of the parasitic Nomada also nearly ready to come out, which
seemed to be identical with some bees noticed playing very innocently
about the holes early in the summer.

On the last day of August, very few of the holes were open. A number of
Oil beetles were strolling suspiciously about in the neighborhood, and
some little black Ichneumon flies were seen running about among the
holes.

During mid-summer the holes were found closed night and day by clods of
earth.

The burrow is sunken perpendicularly, with short passages leading to the
cells, which are slightly inclined downwards and outwards from the main
gallery. The walls of the gallery are rough, but the cells are lined
with a mucous-like secretion, which, on hardening, looks like the
glazing of earthenware. This glazing is quite hard, and breaks up into
angular pieces. It is evidently the work of the bee herself, and is not
secreted and laid on by the larva. The diameter of the interior of the
cell is about one-quarter of an inch, contracting a little at the mouth.
When the cell is taken out, the dirt adheres for a line in thickness, so
that it is of the size and form of an acorn.

The larva of Andrena (Fig. 29) is soft and fleshy, like that of the
Honey bee. Its body is flattened, bulging out prominently at the sides,
and tapering more rapidly than usual towards each end of the body. The
skin is very thin, so that along the back the heart or dorsal vessel may
be distinctly seen, pulsating about sixty times a minute.

Our cut (Fig. 28, _a_) also represents the pupa, or chrysalis, as seen
lying in its cell. The limbs are folded close to the body in the most
compact way possible. On the head of the semi-pupa, _i.e._, a transition
state between the larva and pupa, there are two prominent tubercles
situated behind the simple eyes, or ocelli; these are deciduous organs,
apparently aiding the insect in moving about its cell. They disappear in
the mature pupa.

[Illustration: Fig. 29. Fig. 30. Fig. 31.

Fig. 31. Larva of Halictus parallelus.

Fig. 29. Larva of Andrena vicina.

Fig. 30. Pupa of Halictus parallelus seen from beneath.]

To those accustomed to rearing butterflies, and seeing the chrysalis at
once assuming its perfected shape, after the caterpillar skin is thrown
off, it may seem strange to hear one speak of a "half-pupa," and of
stages intermediate between the larva and pupa. But the external changes
of form, though rapidly passed through, consisting apparently of a mere
sloughing off of the outer skin, are yet preceded by slow and very
gradual alterations of tissues, resulting from the growth of cells. An
inner layer of the larva-skin separates from the outer, and, by changes
in the form of the muscles, is drawn into different positions, such as
is assumed by the pupa, which thus lies concealed beneath the
larva-skin. But a slight alteration is made in the general form of the
larva, consisting mostly of an enlargement of the thoracic segments,
which is often overlooked, even by the special student, though of great
interest to the philosophic naturalist.

From Mr. Emerton's observations we should judge that the pupa state
lasted from three to four weeks, as the larvæ began to transform the
first of August, and appeared during the last week of the same month as
perfect bees.

The Andrena is seen as late as the first week in September, and again
early in April, about the flowers of the willow. It is one of the
largest of its genus and a common species.

Having, in a very fragmentary way, sketched the life history of our
Andrena and had some glimpses of its subterranean life, let us now
compare with it another genus of solitary bee (Halictus), quite closely
allied in all respects, though a little lower in the scale.

The Halictus parallelus excavates cells almost exactly like those of
Andrena; but since the bee is smaller, the holes are smaller, though as
deep. Mr. Emerton found one nest in a path a foot in depth. Another
nest, discovered September 9th, was about six inches deep. The cells are
in form like those of Andrena, and like them, are glazed within. The egg
is rather slenderer and much curved; in form it is long, cylindrical,
obtuse at one end, and much smaller at the other. The larva (Fig. 31) is
longer and slenderer, being quite different from the rather broad and
flattened larva of Andrena. The body is rather thick behind, but in
front tapers slowly towards the head, which is of moderate size. Its
body is somewhat tuberculated, the tubercle aiding the grub in moving
about its cell. Its length is nearly one-half (.40) of an inch. On the
pupa are four quite distinct conical tubercles forming a transverse line
just in front of the ocelli; and there are also two larger, longer
tubercles, on the outer side of each of which, an ocellus is situated.
Figure 30 represents the pupa seen from beneath.

Search was made on July 16th, where the ground was hard as stone for six
inches in depth, below which the soil was soft and fine, and over twenty
cells were dug out. "The upper cells contained nearly mature pupæ, and
the lower ones, larvæ of various sizes, the smallest being hardly
distinguishable by the naked eye. Each of these small larvæ was in a
cell by itself, and situated upon a lump of pollen, which was the size
and shape of a pea, and was found to lessen in size as the larva grew
larger. These young were probably the offspring of several females, as
four mature bees were found in the hole." The larva of an English
species hatches in ten days after the eggs are laid.

Another brood of bees appeared the middle of September, as on the ninth
of that month (1864) Mr. Emerton found several holes of the same species
of bee, made in a hard gravel road near the turnpike. When opened, they
were found to contain several bees with their young. September 2nd, of
this year, the same kind of bee was found in holes, and just ready to
leave the cell. It is probable that these bees winter over.

We have incidentally noticed the presence in the nests of Andrena and
Halictus of a stranger bee, clad in gay, fantastic hues, which lives a
parasitic life on its hosts. This parasitism does not go far enough to
cause the death of the host, since we find the young of the parasitic
Cuckoo bee, in cells containing the young of the former.

Mr. F. Smith, in his "Catalogue of British Bees," says of this genus:
"No one appears to know anything beyond the mere fact of their entering
the burrows of Andrenidæ and Apidæ, except that they are found in the
cells of the working bees in their perfect condition: it is most
probable that they deposit their eggs on the provision laid up by the
working bee, that they close up the cell, and that the working bee,
finding an egg deposited, commences a fresh cell for her own progeny."

He has, however, found two specimens of Nomada, sexfasciata in the cells
of the long-horned bee, Eucera longicornis. He also states, that while
some species are constant in their attacks on certain Halicti and
Andrenæ, others attack different species of these genera
indiscriminately. In like manner another Cuckoo bee (Coelioxys) is
parasitic on Megachile and Saropoda; Stelis is a parasite on Osmia, the
Mason bee: and Melecta infests the cells of Anthophora.

The observations of Mr. Emerton enable us still further to clear up the
history of this obscure visitor. He found both the larva and pupa, as
well as the perfect bee, in the cells of both genera; so that either
both kinds of bee, when hatched from eggs laid in the same cell, feed on
the same pollen mass, which therefore barely suffices for the
nourishment of both; or the hostess, discovering the strange egg laid,
cuckoo-like, in her own nest, has the forethought to deposit another
ball of pollen to secure the safety of her young.

Is such an act the operation of a blind instinct? Does it not rather
ally our little bee with those higher animals which undoubtedly possess
a reasoning power? Its _instinct_ teaches it to build cells, and prepare
its pollen mass, and lay an egg thereon. Its _reason_ enables it, in
such an instance as this, when the life of the brood is threatened, to
guard against any such danger by means to which it does not habitually
resort. This instance is paralleled by the case of our common summer
Yellow bird, which, on finding an egg of the Cow bunting in its nest,
often builds a new nest above it, to the certain destruction of the
unwelcome egg in the nest beneath.

In the structure of the bee, and in all its stages of growth, our
parasite seems lower in the zoölogical scale than its host. It is
structurally a degraded form of Working-bee, and its position socially
is unenviable. It is lazy, not having the provident habits of the
Working-bees; it aids not in the least, so far as we know, the
cross-fertilization of plants--one great office in the economy of nature
which most bees perform,--since it is not a pollen-gatherer, but on the
contrary is seemingly a drag and hinderance to the course of nature. But
yet nature kindly, and as if by a special interposition, provides for
its maintenance, and the humble naturalist can only exclaim, "God is
great, and his ways mysterious," and go on studying and collecting
facts, leaving to his successors the more difficult task, but greater
joy of discovering the cause and reason of things that are but a puzzle
to the philosophers of this day.

The larva of Nomada may be known from those of its host, by its
slenderer body and smaller head, while the body is smoother and more
cylindrical. Both sexes of Nomada imbricata and N. pulchella were found
by Mr. Emerton, the former in both the Andrena and Halictus nests, and
both were found in a single Andrena nest.

[Illustration: Wood Wasp.]




CHAPTER III.

THE PARASITES OF THE HONEY BEE.


Very few bee-keepers are probably aware how many insect parasites infest
the Honey bee. In our own literature we hear almost nothing of this
subject, but in Europe much has been written on bee parasites. From Dr.
Edward Assmuss' little work on the "Parasites of the Honey Bee," we
glean some of the facts now presented, and which cannot fail to interest
the general reader as well as the owner of bees.

The study of the habits of animal parasites has of late gained much
attention among naturalists, and both the honey and wild bees afford
good examples of the singular relation between the host and the
parasites which live upon it. Among insects generally, there are certain
species which devour the contents of the egg of the victim. Others, and
this is the most common mode of parasitism, attack the insect in its
larva state; others, in the pupa state, and still others in the perfect,
or imago state. Dr. Leidy has shown that the wood-devouring species of
beetle, Passalus cornutus, and some Myriopods, or "thousand legs," are,
in some cases, tenanted by myriads of microscopic plants and worms which
luxuriate in the alimentary canal, while the "caterpillar-fungus"
attacks sickly caterpillars, filling out their bodies, and sending out
shoots into the air, so that the insect looks as if transformed into a
vegetable.

The Ichneumon flies, of which there are undoubtedly several thousand
species in this country, are the most common insect parasites. Next to
these are the different species of Tachina and its allied genera. These,
like Ichneumons, live in the bodies of their hosts, consuming the fatty
parts, and finishing their transformations just as the exhausted host
is ready to die, issue from their bodies as flies, closely resembling
the common housefly.

A small fly has been found in Europe to be the most formidable foe of
the hive bee, sometimes producing the well-known disease called
"foul-brood," which is analogous to the typhus fever of man.

[Illustration: 32. Phora and its Young.]

This fly, belonging to the genus Phora (Fig. 32, Phora incrassata; _a_,
larva; _b_, puparium; _c_, another species from Mammoth Cave), is a
small insect about a line and a half long, and found in Europe during
the summer and autumn flying slowly about flowers and windows, and in
the vicinity of beehives. Its white, transparent larva is cylindrical, a
little pointed before, but broader behind. The head is small and
rounded, with short, three-jointed antennæ, and at the posterior end of
the body are several slender spines. The puparium, or pupa case,
inclosing the delicate chrysalis, is oval, consisting of eight segments,
flattened above, with two large spines near the head, and four on the
extremity of the body.

When impelled by instinct to provide for the continuance of its species,
the Phora enters the beehive and gains admission to a cell, when it
bores with its ovipositor through the skin of the bee larva, laying its
long oval egg in a horizontal position just under the skin. The embryo
of the Phora is already well developed, so that in three hours after the
egg is inserted in the body of its unsuspecting and helpless host, the
embryo is nearly ready to hatch. In about two hours more it actually
breaks off the larger end of the egg-shell and at once begins to eat the
fatty tissues of its victim, its posterior half still remaining in the
shell. In an hour more, it leaves the egg entirely and buries itself
completely in the fatty portion of the young bee.

The maggot moults three times. In twelve hours after the last moult it
turns around with its head towards the posterior end of the body of its
host, and in another twelve hours, having become full-fed, it bores
through the skin of the young, eats its way through the brood-covering
of the cell and falls to the bottom of the hive, where it changes to a
pupa in the dust and dirt, or else creeps out of the door and transforms
in the earth. Twelve days after, the fly appears.

The young bee, emaciated and enfeebled by the attacks of its ravenous
parasite, dies, and its decaying body fills the bottom of the cell with
a slimy, foul-smelling mass, called "foul-brood." This gives rise to a
miasma which poisons the neighboring brood, until the contagion (for the
disease is analogous to typhus, jail or ship-fever) spreads through the
whole hive, unless promptly checked by removing the cause and thoroughly
cleansing the hive.

Foul-brood sometimes attacks our American hives, and, though the cause
may not be known, yet from the hints given above we hope to have the
history of our species of Phora cleared up, should our disease be found
to be sometimes due to the attacks of such a parasitic fly.

[Illustration: 33. Bee Louse and Larva.]

We figure the Bee louse of Europe (Fig. 33 b, Braula cæca), which is a
singular wingless spider-like fly, allied to the wingless Sheep tick
(Melophagus), the wingless Bat tick (Nycteribia) and the winged Horse
fly (Hippobosca). The head is very large, without eyes or ocelli (simple
eyes), while the ovate hind-body consists of five segments, and is
covered with stiff hairs. It is one-half to two-thirds of a line long.
This spider fly is "pupiparous," that is, the young, of which only a
very few are produced, is not born until it has assumed the pupa state
or is just about to do so. The larva (Fig. 33 _a_) is oval,
eleven-jointed, and white in color. The very day it is hatched, it sheds
its skin and changes to an oval puparium of a dark brown color.

Its habits resemble those of the flea. Indeed, should we compress its
body strongly, it would bear a striking resemblance to that insect. It
is evidently a connecting link between the flea, and the two winged
flies. Like the former it lives on the body of its host, and obtains its
food by plunging its stout beak into the bee and sucking its blood.

It has not been noticed in this country, but is liable to be imported on
the bodies of Italian bees. Generally, one or two of the Braulas may, on
close examination, be detected on the body of the bee; sometimes the
poor bees are loaded down by as many as a hundred of these hungry
blood-suckers. Assmuss recommends rubbing them off with a feather, as
the bee goes in and out of the door of its hive.

[Illustration: 34. Hive Trichodes.]

Among the beetles are a few forms occasionally found in bees' nests and
also parasitic on the body of the bee. Trichodes apiarius (Fig. 34, _a_,
larva; _b_, pupa, front view) has long been known in Europe to attack
the young bees. In its perfect, or beetle state it is found on flowers,
like our Trichodes Nuttallii, which is commonly found on the Spiræa in
August, and which may yet prove to enter our beehives. The larva devours
the brood, but with the modern hive its ravages may be readily detected.

[Illustration: 35. Meloë.]

The Oil beetle, Meloë angusticollis (Fig. 35, male, differing from the
female by having the antennæ as if twisted into a knot; Fig. 36, the
active larva found on the body of the bee), is a large dark blue insect
found crawling in the grass in the vicinity of the nests of Andrena,
Halictus, and other wild bees in May, and again in August and
September. The eggs are laid in a mass covered with earth at the root
of some plant. During April and early in May, when the willows are in
blossom, we have found the young recently hatched larvæ in considerable
abundance creeping briskly over the bees, or with their heads plunged
between the segments of the body, greedily sucking in the juices of
their host. Those that we saw occurred on the Humble and other wild
bees, and on various flies (Syrphus and Muscidæ), and there is no reason
why they should not infest the Honey bee, which frequents similar
flowers, as they are actually known to do in Europe. These larvæ are
probably hatched out near where the bees hibernate, so as to creep into
their bodies before they fly in the spring, as it would be impossible
for them to crawl up a willow tree ten feet high or more, their feet
being solely adapted for climbing over the hairy body of the bee, which
they do not leave until about to undergo their strange and unusual
transformations.

[Illustration: Early Stages of Meloë.]

In Europe, Assmuss states that on being brought into the nest by the
bee, they leave the bee and devour the eggs in the bee cells, and then
attack the bee bread. When full-fed and ready to pass through their
transformations to attain the beetle state, instead of at once assuming
the pupa and imago forms, as in the Trichodes represented in fig. 34,
they pass through a _hyper-metamorphosis_, as Fabre, a French
naturalist, calls it. In other words, the changes in form which are
preparatory to assuming the pupa and imago states are more marked and
almost coequal with the larva and pupa states, so that the Meloë,
instead of passing through three states (the egg, larva and pupa), in
realty passes through these and two others in addition, which are
intermediate. The whole subject of the metamorphosis of this beetle
needs revision, but Fabre states that the larva, soon after entering the
nest of its host, changes its skin and assumes a second larva form.
Newport, who with Siebold has carefully described the metamorphoses of
Meloë, does not mention this stage in its development, which Fabre calls
"pseudo-chrysalis." It is motionless, the head is mask-like, without
movable appendages, and the feet are represented by six tubercles. This
is more properly speaking the semi-pupa, and the mature pupa grows
beneath its mask-like form, which is finally moulted. This form,
however, according to Fabre, changes its skin and turns into a third
larva form (Fig. 37). After some time it assumes its true pupa form
(Fig. 38), and finally moults this skin to appear as a beetle.

Fabre has also, in a lively and well-written account, given a history of
Sitaris, a European beetle, somewhat resembling Meloë. He states that
Sitaris lays its eggs near the entrance of bees' nests, and at the very
moment that the bee lays her egg in the honey cell, the flattened, ovate
Sitaris larva drops from the body of the bee upon which it has been
living, and feasts upon the contents of the freshly laid egg. After
eating this delicate morsel it devours the honey in the cells of the bee
and changes into a white, cylindrical, nearly footless grub, and after
it is full-fed, and has assumed a supposed "pupa" state, the skin,
without bursting, incloses a kind of hard "pupa" skin, which is very
similar in outline to the former larva, within whose skin is found a
whitish larva which directly changes into the true pupa. In a succeeding
state this pupa in the ordinary way changes to a beetle which belongs to
the same group of Coleoptera as Meloë. We cannot but think, from
observations made on the humble bee, the wasp, two species of moths and
several other insects, that this "hyper-metamorphosis" is not so
abnormal a mode of insect metamorphosis as has been supposed, and that
the changes of these insects, made beneath the skin of the mature larva
before assuming the pupa state, are almost as remarkable as those of
Meloë and Sitaris, though less easily observed than they. Several other
beetles allied to Meloë are known to be parasitic on wild bees, though
the accounts of them are fragmentary.


THE STYLOPS PARASITE.

The history of Stylops, a beetle allied to Meloë, is no less strange
than that of Meloë, and is in some respects still more interesting. On
June 18th I captured an Andrena vicina which had been "stylopized." On
looking at my capture I saw a pale reddish-brown triangular mark on the
bee's abdomen; this was the flattened head and thorax of a female
Stylops (Fig. 39_a_, position of the female of Stylops, seen in profile
in the abdomen of the bee; Fig. 39_b_, the female seen from above. The
head and thorax are soldered into a single flattened mass, the baggy
hind-body being greatly enlarged like that of the gravid female of the
white ant, and consisting of nine segments).

[Illustration: 39. Female Stylops.]

On carefully drawing out the whole body (Pl. 1, Fig. 6, as seen from
above, and showing the alimentary canal ending in a blind sac; Fig.
6_a_, side view), which is very extensible, soft and baggy, and
examining it under a high power of the microscope, we saw multitudes, at
least several hundred, of very minute larvæ, like particles of dust to
the naked eye, issuing in every direction from the body of the parent
now torn open in places, though most of them made their exit through an
opening on the under side of the head-thorax. The Stylops, being hatched
while still in the body of the parent, is, therefore viviparous. She
probably never lays eggs.

On the last of April, when the Mezereon was in blossom, I caught the
singular looking male (Stylops Childreni, Fig. 40; a, side view; it is
about one-fourth of an inch long), which was as unlike its partner as
possible. I laid it under a tumbler, when the delicate insect flew and
tumbled about till it died of exhaustion in a few hours.

It appears, then, that the larvæ are hatched during the middle or last
of June from eggs fertilized in April. The larvæ then crawl out upon the
body of the bee, on which they are transported to the nest, where they
enter, according to Peck's observations, the body of the larva, on whose
fatty parts they feed. Previous to changing to a pupa the larva lives
with its head turned towards that of its host, but before assuming the
perfect state (which they do in the late summer or autumn) it must
reverse its position. The female protrudes the front part of her body
between the segments of the abdomen of her host, as represented in our
figure. This change, Newport thinks, takes place after the bee-host has
undergone its metamorphoses, though the bee does not leave her earthen
cells until the following spring. Though the male Stylops deserts his
host, his wingless partner is imprisoned during her whole life within
her host, and dies immediately after giving birth to her myriad (for
Newport thinks she produces over two thousand) offspring.

[Illustration: 40. Male Stylops.]

Xenos Peckii, an allied insect, was discovered by Dr. Peck to be
parasitic in the body of wasps, and there are now known to be several
species of this small but curious family, Stylopidæ, which are known to
live parasitically on the bodies of our wild bees and wasps. The
presence of these parasites finally exhausts the host, so that the
sterile female bee dies prematurely.

As in the higher animals, bees are afflicted with parasitic worms which
induce disease and sometimes death. The well-known hair worm, Gordius,
is an insect parasite. The adult form is about the size of a slender
knitting needle, and is seen in moist soil and in pools. It lays,
according to Dr. Leidy, "millions of eggs connected together in long
cords." The microscopical, tadpole-shaped young penetrate into the
bodies of insects frequenting damp localities. Fairly ensconced within
the body of their unsuspecting host, they luxuriate on its fatty
tissues, and pass through their metamorphoses into the adult form, when
they desert their living house and take to the water to lay their eggs.
In Europe, Siebold has described Gordius subbifurcus, which infests the
drones of the Honey bee, and also other insects. Professor Siebold has
also described Mermis albicans, which is a similar kind of hair worm,
from two to five inches long, and whitish in color. This worm is also
found, strangely enough, only in the drones, though it is the workers
which frequent watery places to appease their thirst.

[Illustration: 41. Bee fungus.]

Thousands of insects are carried off yearly by parasitic fungi. The
ravages of the Muscardine, caused by a minute fungus (Botrytris
Bassiana), have threatened the extinction of silk culture in Europe, and
the still more formidable disease called _pebrine_ is thought to be of
vegetable origin. Dr. Leidy mentions a fungus which must annually carry
off myriads of the Seventeen Year Locust. A somewhat similar fungus,
Mucor mellitophorus (Fig. 41), infests bees, filling the stomach with
microscopical colorless spores, so as greatly to weaken the insect.

As there is a probability that many insects, parasites on the wild bees,
may sooner or later afflict the Honey bee, and also to illustrate
farther the complex nature of insect parasitism, we will for a moment
look at some other bee parasites.

[Illustration: Pl. 1

PARASITES OF BEES.]

Among the numerous insects preying in some way upon the Humble bee are
to be found other species of bees and moths, flies and beetles. Insect
parasites often imitate their host: Apathus (Plate I, Fig. 1, A.
Ashtoni) can scarcely be distinguished from its host, and yet it lives
cuckoo-like in the cells of the Humble bee, though we know not yet how
injurious it really is. Then there are Conops and Volucella, the
former of which lives like Tachina and Phora within the bee's body,
while the latter devours the brood. The young (Plate I, Figs. 5, 5_a_)
of another fly allied to Anthomyia, of which the Onion fly (Fig. 42) is
an example, is also not unfrequently met with. A small beetle (Plate 1.
Fig. 4, Antherophagus ochraceus) is a common inmate of Humble bees'
nests, and probably feeds upon the wax and pollen. We have also found
several larvæ (Fig. 43) of a beetle of which we do not know the adult
form. Of similar habits is probably a small moth (Nephopteryx Edmandsii,
Plate I, Figs. 2; 2_a_, larva; Fig. 2_b_, chrysalis, or pupa) which
undoubtedly feeds upon the waxen walls of the bee cells, and thus, like
the attacks of the common bee moth (Galleria cereana, whose habits are
so well known as not to detain us, must prove very prejudicial to the
well being of the colony. This moth is in turn infested by an Ichneumon
fly (Microgaster nephoptericis, Plate I, Figs. 3, 3_a_) which must prove
quite destructive.

[Illustration: 42. Onion Fly and Maggot.]

[Illustration: 43. Larva of Beetle.]

The figures of the early stages of a minute ichneumon represented on the
same plate (Fig. 7, larva, and 7_a_, pupa, of Anthophorabia megachilis)
which is parasitic on Megachile, the Leaf-cutter bee, illustrates the
transformations of the Ichneumon flies, the smallest species of which
yet known (and we believe the smallest insect known at all) is the
Pteratomus Putnami (Pl. I, Fig. 8, wanting the hind leg), or "winged
atom," which is only one-ninetieth of an inch in length, and is
parasitic on Anthophorabia, itself a parasite. A species of mite (Plate
I, Figs. 9; 9_a_, the same seen from beneath) is always to be found In
humble bees' nests, but it is not thought to be specially obnoxious to
the bees themselves, though several species of mites (Gamasus, etc.) are
known to be parasitic on insects.




CHAPTER IV.

A FEW WORDS ABOUT MOTHS.


The butterflies and moths from their beauty and grace, have always been
the favorites among amateur entomologists, and rare and costly works
have been published in which their forms and gorgeous colors are
represented in the best style of natural history art. We need only
mention the folio volume of Madam Merian of the last century, Harris's
Aurelian, the works of Cramer, Stoll, Drury, Hübner, Horsfield,
Doubleday and Westwood, and Hewitson, as comprising the most luxurious
and costly entomological works.

Near the close of the last century, John Abbot went from London and
spent several years in Georgia, rearing the larger and more showy
butterflies and moths, and painting them in the larva, chrysalis and
adult, or imago stage. These drawings he sent to London to be sold. Many
of them were collected by Sir James Edward Smith, and published under
the title of "The Natural History of the Rarer Lepidopterous Insects of
Georgia, collected from the Observations of John Abbot, with the Plants
on which they Feed." (London, 1797. 2 vols., fol.) Besides these two
rare volumes there are sixteen folio volumes of drawings by Abbot in the
Library of the British Museum. This work is of especial interest to the
American student as it illustrates the early stages of many of our
butterflies and moths.

Indeed the study of insects possesses most of its interest when we
observe their habits and transformations. Caterpillars are always to be
found, and with a little practice are easy to raise; we would therefore
advise any one desirous of beginning the study of insects to take up the
butterflies and moths. They are perhaps easier to study than any other
group of insects, and are more ornamental in the cabinet. As a
scientific study we would recommend it to ladies as next to botany in
interest and in the ease in which specimens may be collected and
examined. The example of Madam Merian, and several ladies in this
country who have greatly aided science by their well filled cabinets,
and critical knowledge of the various species and their transformations,
is an earnest of what may be expected from their followers. Though the
moths are easy to study compared with the bees, flies, beetles and bugs,
and dragon flies, yet many questions of great interest in philosophical
entomology have been answered by our knowledge of their structure and
mode of growth. The great works of Herold on the evolution of a
caterpillar; of Lyonet on the anatomy of the Cossus; of Newport on that
of the Sphinx; and of Siebold on the parthenogenesis of insects, are
proofs that the moths have engaged the attention of some of the master
minds in science.

The study of the transformations of the moths is also of great
importance to one who would acquaint himself with the questions
concerning the growth and metamorphoses and origin of animals. We should
remember that the very words "metamorphosis" and "transformation," now
so generally applied to other groups of animals and used in
philosophical botany, were first suggested by those who observed that
the moth and butterfly attain their maturity only by passing through
wonderful changes of form and modes of life.

The knowledge of the fact that all animals pass through some sort of a
metamorphosis is very recent in physiology. Moreover the fact that these
morphological eras in the life of an individual animal accord most
unerringly with the gradation of forms in the type of which it is a
member, was the discovery of the eminent physiologist Von Baer. Up to
this time the true significance of the luxuriance and diversity of
larval forms had never seriously engaged the attention of systematists
in entomology.

What can possibly be the meaning of all this putting on and taking off
of caterpillar habiliments, or in other words, the process of moulting,
with the frequent changes in ornamentation, and the seeming
fastidiousness and queer fancies and strange conceits of these young and
giddy insects seems hidden and mysterious to human observation. Indeed,
few care to spend the time and trouble necessary to observe the insect
through its transformations; and that done, if only the larva of the
perfect insect can be identified and its form sketched how much was
gained! A truthful and circumstantial biography, in all its relations,
of a single insect has yet to be written!

We should also apply our knowledge of the larval forms of insects to the
details of their classification into families and genera, constantly
collating our knowledge of the early stages with the structural
relations that accompany them in the perfect state.

The simple form of the caterpillar seems to be a concentration of the
characters of the perfect insect, and presents easy characters by which
to distinguish the minor groups; and the relative rank of the higher
divisions will only be definitely settled when their forms and methods
of transformation are thoroughly known. Thus, for example, in two groups
of the large Attacus-like moths, which are so amply illustrated in Dr.
Harris's "Treatise on Insects injurious to Vegetation"; if we take the
different forms of the caterpillars of the Tau moth of Europe, which are
figured by Duponchel and Godard, we find that the very young larva has
four horn-like processes on the front, and four on the back part of the
body. The full grown larva of the Regalis moth, of the Southern and
Middle states, is very similarly ornamented. It is an embryonic form,
and therefore inferior in rank to the Tau moth. Multiply these horns
over the surface of the body, lessen their size, and crown them with
hairs, and we have our Io moth, so destructive to corn. Now take off the
hairs, elongating and thinning out the tubercles, and make up the loss
by the increased size of the worm, and we have the caterpillar of our
common Cecropia moth. Again, remove the naked tubercles almost wholly,
smooth off the surface of the body, and contract its length, thus giving
a greater convexity and angularity to the rings, and we have before us
the larva of the stately Luna moth that tops this royal family. Here are
certain criteria for placing these insects before our minds in the order
that nature has placed them. We have certain facts for determining which
of these three insects is highest and which lowest in the scale, when we
see the larva of the Luna moth throwing off successively the Io and
Cecropia forms to take on its own higher features. So that there is a
meaning in all this shifting of insect toggery.

This is but an example of the many ways in which both pleasure and
mental profit may be realized from the thoughtful study of caterpillar
life.

In collecting butterflies and moths for cabinet specimens, one needs a
gauze net a foot and a half deep, with the wire frame a foot in
diameter; a wide-mouthed bottle containing a parcel of cyanide of
potassium gummed on the side, in which to kill the moths, which should,
as soon as life is extinct, be pinned in a cork-lined collecting box
carried in the coat pocket. The captures should then be spread and dried
on a grooved setting board, and a cabinet formed of cork-lined boxes or
drawers; as a substitute for cork, frames with paper tightly stretched
over them may be used, or the pith of corn-stalks or palm wood.
Caterpillars should be preserved in spirits, or in glycerine with a
little alcohol added.

Some persons ingeniously empty the skins and inflate them over a flame
so that they may be pinned by the side of the adult.

Some of the most troublesome and noxious insects are found among the
moths. I need only mention the canker worm and American tent
caterpillar, and the various kinds of cut worms, as instances.

[Illustration: 43. Parasite of the American Silk Worm.]

We must not, however, forget the good done by insects. They undoubtedly
tend by their attacks to prevent an undue growth of vegetation. The
pruning done to a tree or herb by certain insects undoubtedly causes a
more healthy growth of the branches and leaves, and ultimately a greater
production fruit. Again, as pollen-bearers, insects are a most powerful
agency in nature. It is undoubtedly the fact that the presence, of bees
in orchards increases the fruit crop, and thus the thousands of moths
(though injurious as caterpillars), wild bees and other insects, that
seem to live without purpose, are really, though few realize it, among
the best friends and allies of man.

Moreover, insects are of great use as scavengers; such are the young or
maggots of the house fly, the mosquitoes, and numerous other forms, that
seem created only to vex us when in the winged state. Still a larger
proportion of insects are directly beneficial from their habit of
attacking injurious species, such as the ichneumons (Fig. 43, the
ichneumon of the American silk worm) and certain flies (Fig. 44,
Tachina); also many carnivorous species of wasps beetles and flies,
dragon flies and Aphis lions (Fig. 45, the lace-winged fly; adult, larva
and eggs).

[Illustration: 44. Tachina, parasite of Colorado Potato Beetle.]

[Illustration: 45. The Lace-winged Fly, Its Larva and Eggs.]

But few, however, suspect how enormous are the losses to crops in this
country entailed by the attacks of the injurious species. In Europe, the
subject of applied entomology has always attracted a great deal of
attention. Most sumptuous works, elegant quartos prepared by naturalists
known the world over, and published at government expense, together with
smaller treatises, have frequently appeared; while the subject is taught
in the numerous agricultural colleges and schools, especially of
Germany.

In the densely populated countries of Europe, the losses occasioned by
injurious insects are most severely felt, though from many causes, such
as the greater abundance of their insect parasites, and the far greater
care taken by the people to exterminate their insect enemies, they have
not proved so destructive as in our own land.

In this connection I may quote from one of Dr. Asa Fitch's reports on
the noxious insects of New York, where he says: "I find that in our
wheat-fields here, the midge formed 59 per cent. of all the insects on
this grain the past summer; whilst in France, the preceding summer, only
7 per cent. of the insects on wheat were of this species. In France the
parasitic destroyers amounted to 85 per cent.; while in this country our
parasites form only 10 per cent."

"A true knowledge of practical entomology may well be said to be in its
infancy in our own country, when, as is well-known to agriculturists,
the cultivation of wheat has almost been given up in New England, New
York, Pennsylvania, Ohio and Virginia, from the attacks of the wheat
midge, Hessian fly, joint worm, and chinch bug. According to Dr.
Shimer's estimate, says Mr. Riley, in his Second Annual Report on the
Injurious Insects of Missouri, which may be considered a reasonable
one, in the year 1864 three-fourths of the wheat, and one-half of the
corn crop were destroyed by the chinch bug throughout many extensive
districts, comprising almost the entire North-West. At the annual rate
of increase, according to the United States Census, in the State of
Illinois, the wheat crop ought to have been about thirty millions of
bushels, and the corn crop about one hundred and thirty-eight million
bushels. Putting the cash value of wheat at $1.25, and that of corn at
50 cents, the cash value of the corn and wheat destroyed by this
insignificant little bug, no bigger than a grain of rice, in one single
State and one single year, will therefore, according to the above
figures, foot up to the astounding total of _over seventy-three millions
of dollars_!"

The imported cabbage butterfly (Pieris rapæ), recently introduced from
Europe, is estimated by the Abbé Provatncher, a Canadian entomologist,
to destroy annually two hundred and forty thousand dollars' worth of
cabbages around Quebec. The Hessian fly, according to Dr. Fitch,
destroyed fifteen million dollars' worth of wheat in New York State in
one year (1854). The army worm of the North (Leucania unipuncta), which
was so abundant in 1861, from New England to Kansas, was reported to
have done damage that year in Eastern Massachusetts exceeding half a
million of dollars. The joint worm (Isosoma hordei) alone sometimes cuts
off whole fields of grain in Virginia and northward. The Colorado potato
beetle is steadily moving eastward, now ravaging the fields in Indiana
and Ohio, and only the forethought and ingenuity in devising means of
checking its attacks, resulting from a thorough study of its habits,
will deliver our wasted fields from its direful assaults.

These are the injuries done by the more abundant kinds of insects
injurious to crops. We should not forget that each fruit or shade tree,
garden shrub or vegetable, has a host of insects peculiar to it, and
which, year after year, renew their attacks. I could enumerate upwards
of fifty species of insects which prey upon cereals and grass, and as
many which infest our field crops. Some thirty well known species ravage
our garden vegetables. There are nearly fifty species which attack the
grape vine, and their number is rapidly increasing. About seventy-five
species make their annual onset upon the apple tree, and nearly an equal
number may be found upon the plum, pear, peach and cherry. Among our
shade trees, over fifty species infest the oak; twenty-five the elm;
seventy-five the walnut, and over one hundred species of insects prey
upon the pine.

Indeed, we may reasonably calculate the annual loss in our country
alone, from noxious animals and the lower forms of plants, such as rust,
smut and mildew, as (at a low estimate) not far from five hundred
million dollars annually. Of this amount, at least one-tenth, or fifty
million dollars, could probably be saved by human exertions.

To save a portion of this annual loss of food stuffs, fruits and lumber,
should be the first object of farmers and gardeners. When this saving is
made, farming will become a profitable and safe profession. But while a
few are well informed as to the losses sustained by injurious insects,
and use means to ward off their attacks, their efforts are constantly
foiled by the negligence of their neighbors. As illustrated so well by
the history of the incursions of the army worm and canker worm, it is
only by a combination between farmers and orchardists that these and
other pests can be kept under. The matter can be best reached by
legislation. We have fish and game laws; why should we not have an
insect law? Why should we not frame a law providing that farmers, and
all owning a garden or orchard, should cooperate in taking preventive
measures against injurious insects, such as early or late planting of
cereals, to avert the attacks of the wheat midge and Hessian fly; the
burning of stubble in the autumn and spring to destroy the joint worm;
the combined use of proper remedies against the canker worm, the
various cut worms, and other noxious caterpillars? A law carried out by
a proper State entomological constabulary, if it may be so designated,
would compel the idle and shiftless to clear their farms and gardens of
noxious animals.

[Illustration: 46. Pickle Worm and its Moth.]

Among some of the injurious insects reported on by Mr. Riley, the State
Entomologist of Missouri, is a new pest to the cucumber in the West, the
Pickle worm (Phacellura nitidalis, Fig. 46). This is a caterpillar which
bores into the cucumbers when large enough to pickle, and which is
occasionally found in pickles. Three or four worms sometimes occur in a
cucumber, and in the garden a single one will cause it to rot. One of
the most troublesome intruders in our graperies is the Vine dresser
(Choerocampa pampinatrix, Fig. 47, larva and pupa; Fig. 48, adult), a
single caterpillar of which will sometimes "strip a small vine of its
leaves in a few nights," and occasionally nips off bunches of half-grown
grapes.

[Illustration: 48. Vine Dresser Moth.

47. Vine Dresser and Chrysalis.]

Another caterpillar, which is sometimes so abundant as nearly to
defoliate the grape vine, is the eight spotted Alypia (Fig. 49; _a_,
larva; _b_, side view of a segment). This must not be confounded with
the bluish larva of the Wood Nymph, Eudryas grata (Fig. 50), which
differs from the Alypia caterpillar in being bluish, and in wanting the
white patches on the side of the body, and the more prominent hump on
the end of the body. Another moth (Psychomorpha epimenis, Fig. 51,
_a_, larva; _b_, side view of a segment; _c_, top view of the hump),
also feeds on the grape, eating the terminal buds. It is also bluish,
and wants the orange bands on the side of the body. Another moth of this
family is the American Procris (Acoloithus Americana, Fig. 52_a_, larva;
_b_, pupa; _c_, cocoon; _d_, _e_, imago); a dark blue moth, with a deep
orange collar, whose black and yellow caterpillar is gregarious (Fig.
53), living in companies of a dozen or more and eating the softer parts
of the leaves. It is quite common in the Western and Southern States.
The figure represents two separate broods of caterpillars feeding on
either side of the midrib of the leaf. But if the moths are, as a rule,
the enemies of our crops, there are the silk worms of the East and
Southern Europe and California, which afford the means of support to
multitudes of the poorer classes, and supply one of the most valuable
articles of clothing. Blot out the silk worm, and we should remove one
of the most important sources of national wealth, the annual revenue
from the silk trade of the world amounting to $254,500,000.

[Illustration: 49. Eight-spotted Alypia and Larva.]

[Illustration: 50. Eudryas grata.]

[Illustration: 51. Larva of Psychomorpha.]

[Illustration: 52. American Procris and Young.]

[Illustration: 53. Larvæ of American Procris.]

Silk culture is rapidly assuming importance in California, and though
the Chinese silk worm has not been successfully cultivated in the
Eastern States, yet the American silk worm, Teleas Polyphemus (see
frontispiece, male; Fig. 54, larva; 55, pupa; 56, cocoon), can, we are
assured by Mr. Trouvelot, be made a source of profit.

This is a splendid member of the group of which the gigantic Attacus
Atlas of China is a type. It is a large, fawn colored moth with a tawny
tinge; the caterpillar is pale green, and is of the size indicated in
the cut. Mr. Trouvelot says that of the several kinds of silk worms, the
larva of the present species alone deserves attention. The cocoons of
Platysamia Cecropia may be rendered of some commercial value, as the
silk can be carded, but the chief objection is the difficulty of raising
the larva.

"The Polyphemus worm spins a strong, dense, oval cocoon, which is closed
at each end, while the silk has a very strong and glossy fibre." Mr.
Trouvelot, from whose interesting account in the first volume of the
"American Naturalist" we quote, says that in 1865 "not less than a
million could be seen feeding in the open air upon bushes covered with a
net; five acres of woodland were swarming with caterpillar life." The
bushes were scrub oaks, the worms being protected by a net. After
meeting with such great success Mr. Trouvelot lost all his worms by
pebrine, the germs being imported in eggs received from Japan through M.
Guérin-Méneville of Paris. Enough, however, was done to prove that silk
raising can be carried on profitably, when due precautions are taken, as
far north as Boston. As this moth extends to the tropics, it can be
reared with greater facility southwards. The cocoon is strong and dense,
and closed at each end, so that the thread is continuous, while the silk
has a very strong and glossy fibre.

[Illustration: 54. American Silk Worm.]

Next in value to the American silk worm, is the Ailanthus silk worm
(Samia Cynthia) a species allied to our Callosamia Promethea. It
originated from China, where it is cultivated, and was introduced into
Italy in 1858, and thence spread into France, where it was introduced by
M. Guérin-Méneville. Its silk is said to be much stronger than the fibre
of cotton, and is a mean between fine wool and ordinary silk. The worm
is very hardy, and can be reared in the open air both in this country
and in Europe. The main drawback to its culture is the difficulty in
unreeling the tough cocoon, and the shortness of the thread, the cocoon
being open at one end.

The Yama-maï moth (Antheræa Yama-maï) was introduced into France from
Japan in 1861. It is closely allied to the Polyphemus moth, and its
caterpillar also feeds on the oak. Its silk is said to be quite
brilliant, but a little coarser and not so strong as that of the Bombyx
mori. The Perny silk worm is extensively cultivated by the Chinese in
Manchouria, where it feeds on the oak. Its silk is coarser than that of
the common silk worm, but is yet fine, strong and glossy. Bengal has
furnished the Tussah moth, which lives in India on the oak and a variety
of other trees. It is largely raised in French and English India,
according to Nogués, and is used in the manufacture of stuffs called
corahs.

[Illustration: 55. Chrysalis of American Silk Worm.]

[Illustration: 56. Cocoon of American Silk Worm.]

The last kind of importance is the Arrhindy silk worm, from India. It
has been naturalized in France and Algeria by M. Guérin-Méneville, who
has done so much in the application of entomology to practical life. It
is closely allied to the Cynthia or Ailanthus worm, with the same kind
of silk and a similar cocoon, and feeds on the castor oil plant.

The diseases of silk worms naturally receive much attention. Like those
afflicting mankind, they arise from bad air, resulting from too close
confinement, bad food, and other adverse causes. The most fatal and
wide-spread disease, and one which since 1854 has threatened the
extermination of silk worms in Europe, is the _pebrine_. It is due to
the presence of minute vegetable corpuscles, which attack both the worms
and the eggs. It was this disease which swept off thousands of Mr.
Trouvelot's Polyphemus worms, and put a sudden termination to his
important experiments, the germs having been implanted in eggs of the
Yama-maï moth imported from Japan by M. Guérin-Méneville, and which were
probably infected as they passed through Paris. Though the disaster
happened several years since, he tells us that it will be useless for
him to attempt the raising of silk worms in the town where his
establishment is situated, as the germs of the disease are most
difficult to eradicate.

So direful in France were the ravages of this disease that two of the
most advanced naturalists in France, Quatrefages and Pasteur, were
commissioned by the French government to investigate the disease.
Pasteur found that the infected eggs differed in appearance from the
sound ones, and could thus be sorted out by aid of the microscope and
destroyed. Thus these investigations, carried on year after year, and
seeming to the ignorant to tend to no practical end, resulted in saving
to France her silk culture. During the past year (1871) so successful
has his method proved that a French scientific journal expresses the
hope of the complete reestablishment and prosperity of this great
industry. A single person who obtained in 1871 in his nurseries 30,000
ounces of eggs, hopes the next year to obtain 100,000 ounces, from which
he expects to realize about one million dollars.

[Illustration: The Potato Caterpillar.]




CHAPTER V.

THE CLOTHES MOTH.


For over a fortnight we once enjoyed the company of the caterpillar of a
common clothes moth. It is a little pale, delicate worm (Fig. 57,
magnified), about the size of a darning needle, and rather less than
half an inch in length, with a pale horn-colored head, the ring next the
head being of the same color. It has sixteen feet, the first six of them
well developed and constantly in use to draw the slender body in and out
of its case. Its head is armed with a formidable pair of jaws, with
which, like a scythe, it mows its way through thick and thin.

But the case is the most remarkable feature in the history of this
caterpillar. Hardly has the helpless, tiny worm broken out of the egg,
previously laid in some old garment of fur or wool, or perhaps in the
haircloth of a sofa, when it begins to make a shelter by cutting the
woolly fibres or soft hairs into bits, which it places at each end in
successive layers, and, joining them together by silken threads,
constructs a cylindrical tube (Fig. 58) of thick, warm felt, lined
within with the finest silk the tiny worm can spin. The case is not
perfectly cylindrical, being flattened slightly in the middle, and
contracted a little just before each end, both of which are always kept
open. The case before us is of a stone-gray color, with a black stripe
along the middle, and with rings of the same color round each opening.
Had the caterpillar fed on blue or yellow cloth, the case would, of
course, have been of those colors. Other cases, made by larvæ which had
been eating loose cotton, were quite irregular in form, and covered
loosely with bits of cotton thread, which the little tailor had not
trimmed off.

Days go by. A vigorous course of dieting on its feast of wool has given
stature to our hero. His case has grown uncomfortably small. Shall he
leave it and make another? No housewife is more prudent and saving. Out
come those scissor-jaws, and, lo! a fearful rent along each side of one
end of the case. Two wedge-shaped patches mend the breach; the
caterpillar retires for a moment and reappears at the other end; the
scissors are once more pulled out; two rents appear, to be filled up by
two more patches or gores, and our caterpillar once again breathes more
freely, laughs and grows fat upon horse hair and lambs' wool. In this
way he enlarges his case till he stops growing.

[Illustration: 59. 58. 57.

Early Stages of the Clothes Moth.]

Our caterpillar seeming to be full-grown, and apparently out of
employment, we cut the end of his case half off. Two or three days
after, he had mended it from the inside, drawing the two edges together
by silken threads, and, though he had not touched the outside, yet so
neatly were the two parts joined together that we had to search for some
time, with a lens, to find the scar.

To keep our friend busy during the cold, cheerless weather, for it was
mid-winter, we next cut a third of the case entirely off. Nothing
daunted, the little fellow bustled about, drew in a mass of the woolly
fibres, filling up the whole mouth of his den, and began to build on
afresh, and from the inside, so that the new-made portion was smaller
than the rest of the case. The creature worked very slowly, and the
addition was left in a rough, unfinished state.

We could easily spare these voracious little worms hairs enough to serve
as food, and to afford material for the construction of their paltry
cases; but that restless spirit that ever urges on all beings endowed
with life and the power of motion, never forsakes the young clothes moth
for a moment. He will not be forced to drag his heavy case over rough
hairs and furzy wool, hence with his keen jaws he cuts his way through.
Thus, the more he travels, the more mischief he does.

After taking his fill of this sort of life he changes to a chrysalid
(Fig. 59), and soon appears as one of those delicate, tiny, demure
moths that fly in such numbers from early in the spring until the
autumn.

Very many do not recognize these moths in their perfect stage, so small
are they, and vent their wrath on those great millers that fly around
lamps in warm summer evenings. It need scarcely be said that these large
millers are utterly guiltless of any attempts upon our wardrobes; they
make their attacks in a more open form on our gardens and orchards.

We will give a more careful description of the clothes moth, which was
found in its different stages June 12th in a mass of loose cotton. The
larva is white, with a tolerably plump body, which tapers slightly
towards the tail, while the head is much of the color of gum-copal. The
rings of the body are thickened above, especially on the thoracic ones,
by two transverse thickened folds. It is one-fifth of an inch long.

The body of the chrysalis, or pupa, is considerably curved, with the
head smooth and rounded. The long antennæ, together with the hind legs,
which are folded along the breast, reach to the tip of the hind body, on
the upper surface of each ring of which is a short transverse row of
minute spines, which aid the chrysalis in moving towards the mouth of
its case, just before the moth appears. At first the chrysalis is
whitish, but just before the exclusion of the moth becomes the color of
varnish.

When about to cast its pupa skin, the skin splits open on the back, and
the perfect insect glides out. The act is so quickly over with, that the
observer has to look sharp to observe the different steps in the
operation.

[Illustration: 60. Clothes Moth.]

Our common clothes moth (Tinea flavifrontella, Fig. 60) is of a uniform
light-buff color, with a silky iridescent lustre, the hind wings and
abdomen being a little paler. The head is thickly tufted with hairs and
is a little tawny, and the upper side of the densely hirsute feelers
(palpi) is dusky. The wings are long and narrow, with the most beautiful
and delicate long silken fringe, which increases in length towards the
base of the wing.

They begin to fly in May, and last all through the season, fluttering
with a noiseless, stealthy flight in our apartments, and laying their
eggs in our woollens.

Successive broods of the clothes moth appear through the summer. In the
autumn they cease eating, retire within their cases, and early in spring
assume the chrysalis state.

There are several allied species which have much the same habits, except
that they do not all construct cases, but eat carpets, clothing,
articles of food, grain, etc., and objects of natural history.

Careful housewives are not much afflicted with these pests. The slovenly
and thriftless are overrun with them. Early in June woollens and furs
should be carefully dusted, shaken and beaten. Dr. T. W. Harris states
that "powdered black pepper, strewed under the edge of carpets, is said
to repel moths. Sheets of paper sprinkled with spirits of turpentine,
camphor in coarse powder, leaves of tobacco, or shavings of Russia
leather, should be placed among the clothes when they are laid aside for
the summer; and furs and other small articles can be kept by being sewed
in bags with bits of camphor wood, red cedar, or of Spanish cedar; while
the cloth lining of carriages can be secured forever from the attacks of
moths by being washed or sponged on both sides with a solution of the
corrosive sublimate of mercury in alcohol, made just strong enough not
to leave a white stain on a black feather." The moths can be most
readily killed by pouring benzine among them, though its use must be
much restricted from the disagreeable odor which remains. The recent
experiments made with carbolic acid, however, convince us that this will
soon take the place of other substances as a preventive and destroyer of
noxious insects.

[Illustration: The Juniper Sickle-wing.]




CHAPTER VI.

THE MOSQUITO AND ITS FRIENDS.


The subject of flies becomes of vast moment to a Pharaoh, whose ears are
dinned with the buzz of myriad winged plagues, mingled with angry cries
from malcontent and fly-pestered subjects; or to the summer traveller in
northern lands, where they oppose a stronger barrier to his explorations
than the loftiest mountains or the broadest streams; or to the African
pioneer, whose cattle, his main dependence, are stung to death by the
Tsetze fly; or the fariner whose eyes on the evening of a warm spring
day, after a placid contemplation of his growing acres of wheat blades,
suddenly detects in dismay clouds of the Wheat midge and Hessian fly
hovering over their swaying tops. The subject, indeed, has in such cases
a national importance, and a few words regarding the main points in the
habits of flies--how they grow, how they do not grow (after assuming the
winged state), and how they bite; for who has not endured the smart and
sting of these dipterous Shylocks, that almost torment us out of our
existence while taking their drop of our heart's blood--may be welcome to
our readers.

[Illustration: 61. Head of the Mosquito.]

The Mosquito will be our first choice. As she leaps off from her light
bark, the cast chrysalis skin of her early life beneath the waters, and
sails away in the sunlight, her velvety wings fringed with silken hairs,
and her neatly bodiced trim figure (though her nose is rather salient,
considering that it is half as long as her entire body), present a
beauty and grace of form and movement quite unsurpassed by her dipterous
allies. She draws near and softly alights upon the hand of the charmed
beholder, subdues her trumpeting notes, folds her wings noiselessly upon
her back, daintily sets down one foot after the other, and with an
eagerness chastened by the most refined delicacy for the feelings of her
victim, and with the air of Velpeau redivivus, drives through crushed
and bleeding capillaries, shrinking nerves and injured tissues, a
many-bladed lancet of marvellous fineness, of wonderful complexity and
fitness. While engorging herself with our blood, we will examine under
the microscope the mosquito's mouth. The head (Fig. 61) is rounded, with
the two eyes occupying a large part of the surface, and nearly meeting
on the top of the head. Out of the forehead, so to speak, grow the long,
delicate, hairy antennm (_a_), and just below arises the long beak which
consists of the bristle-like maxillæ (_mx_, with their palpi, _mp_) and
mandibles (_m_), and the single hair-like labrum, these five
bristle-like organs being laid in the hollowed labium (_l_). Thus massed
into a single awl-like beak, the mosquito, without any apparent effort,
thrusts them all except the labium into the flesh. Her hind body may be
seen tilling with the red blood, until it cries quits, and the insect
withdraws its sting and flies sluggishly away. In a moment the wounded
parts itch slightly, though a very robust person may not notice the
irritation, or a more delicate individual if asleep; though if weakened
by disease, or if stung in a highly vascular and sensitive part, such as
the eyelid, the bite becomes really a serious matter. Multiply the
mosquito a thousand fold, and one flees their attacks and avoids their
haunts as he would a nest of hornets. Early in spring the larva (Fig.
62, A) of the mosquito may be found in pools and ditches. It remains at
the bottom feeding upon decaying matter (thus acting as a scavenger, and
in this state doing great benefit in clearing swamps of miasms), until
it rises to the surface for air, which it inhales through a single
respiratory tube (_c_) situated near the tail. When about to transform
into the pupa state, it contracts and enlarges anteriorly near the
middle, the larval skin is thrown off, and the insect appears in quite a
different form (Fig. 62, a). The head and thorax are massed together,
the rudiments of the mouth parts and of the wings and legs being folded
upon the breast, while there are two breathing tubes (_d_) situated upon
the back instead of the tail, which ends in two broad paddles (_a_); so
that it comes to the surface, head foremost instead of tail first, a
position according better with its increased age and experience in pond
life. In a few days the pupa skin is cast; the insect, availing itself
of its old habiliments as a raft upon which to float while its body is
drying, grows lighter, and its wings expand for its marriage flight. The
males are beautiful, both physically and morally, as they do not bite;
their manners are more retiring than those of their stronger minded
partners, as they rarely enter our dwellings, and live unnoticed in the
woods. They may be easily distinguished from the females by their long
maxillary palpi, and their thick, bushy, feathered antennæ. The female
lays her elongated, oval eggs in a boat-shaped mass, which floats on the
water. A mosquito lives three or four weeks in the water before changing
to the adult or winged stage. How many days they live in the latter
state we do not know.

[Illustration: 62. Larva and Pupa of the Mosquito.]

Our readers will understand, then, that all flies, like our mosquito for
example, grow while in the larva and pupa state, _and after they acquire
wings do not grow_, so that the small midges are not young mosquitoes,
but the adult winged forms of an entirely different species and genus of
fly; and the myriads of small flies, commonly supposed to be the young
of larger flies, are adult forms belonging to different species of
different genera, and perhaps of different families of the suborder of
Diptera. The typical species of the genus Culex, to which the mosquito
belongs, is Culex pipiens, described by Linnæus, and there are already
over thirty North American species of this genus described in various
works. Few insects live in the sea, but along the coast of New England
a small, slender white larva (Fig. 63a, magnified, and head greatly
enlarged; Fig. 64, pupa and fore foot of larva, showing the hooks),
whose body is no thicker than a knitting needle, lives between tides,
and has even been dredged at a depth of over a hundred feet, which
transforms into a yellow mosquito-like fly (Fig. 65, with head of the
female, magnified) which swarms in summer in immense numbers. I have
called it provisionally Chironomus oceanicus, or Ocean gnat. The larvæ
of other species have been found by Mr. S. I. Smith living at great
depths in our Northern lakes. These kinds of gnats are usually seen
early in spring hovering in swarms in mid air.

[Illustration: 65. Ocean Gnat.]

[Illustration: 63. Larva of Ocean Gnat.]

[Illustration: 64. Pupa of Ocean Gnat.]

The strange fact has been discovered by Grimm, a Russian naturalist,
that the pupa of a feathered gnat is capable of laying eggs which
produce young during the summer time. Previous to this it had been
discovered that a larva of a gnat (Fig. 66 _a_, eggs from which the
young are produced) which lives under the bark of trees in Europe, also
produced young born alive.

The Hessian fly (Fig. 67, _a_, larva; _b_ pupa; _c_, stalk of wheat
injured by larvæ) and Wheat midge, which are allied to the mosquito, are
briefly referred to in the calendar, so that we pass over these to
consider another pest of our forests and prairies.

[Illustration: 66. Viviparous gall larva.]

[Illustration: 67. Hessian Fly and its Young.]

The Black fly is even a more formidable pest than the mosquito. In the
northern, subarctic regions, it opposes a barrier against travel. The
Labrador fisherman spends his summer on the sea shore, scarcely daring
to penetrate the interior on account of the swarms of these flies.
During a summer residence on this coast, we sailed up the Esquimaux
river for six or eight miles, spending a few hours at a house situated
on the bank. The day was warm and but little wind blowing, and the
swarms of black flies were absolutely terrific. In vain we frantically
waved our net among them, allured by some rare moth; after making a few
desperate charges in the face of the thronging pests, we had to retire
to the house, where the windows actually swarmed with them; but here
they would fly in our faces, crawl under one's clothes, where they even
remain and bite in the night. The children in the house were sickly and
worn by their unceasing torments; and the shaggy Newfoundland dogs whose
thick coats would seem to be proof against their bites ran from their
shelter beneath the bench and dashed into the river, their only retreat.
In cloudy weather, unlike the mosquito, the black fly disappears, only
flying when the sun shines. The bite of the black fly is often severe,
the creature leaving a large clot of blood to mark the scene of its
surgical triumphs. Prof. E. T. Cox, State Geologist of Indiana, has sent
us specimens of a much larger fly, which Baron Osten Sacken refers to
this genus, which is called on the prairies, where it is said to bite
horses to death, the Buffalo Gnat. Westwood states that an allied fly
(Rhagio Columbaschensis) is one of the greatest scourges of man and
beast in Hungary, where it has been known to kill cattle.

[Illustration: 68. Black fly.]

[Illustration: 69. Black Fly Larva.]

The Simulium molestum (Fig. 68, enlarged), as the black fly is called,
lives during the larva state in the water. The larva of a Labrador
species (Fig. 69, enlarged) which we found, is about a quarter of an
inch long, and of the appearance here indicated. The pupa is also
aquatic, having long respiratory filaments attached to each side of the
front of the thorax. According to Westwood, "the posterior part of its
body is enclosed in a semioval membranous cocoon, which is at first
formed by the larva, the anterior part of which is eaten away before
changing to a pupa, so as to be open in front. The imago is produced
beneath the surface of the water, its fine silky covering serving to
repel the action of the water."

[Illustration: 70. Mycetobia.]

Multitudes of a long, slender, white worm may often be found living in
the dirt, and sour sap running from wounds in the elm tree. Two summers
ago we discovered some of these larvæ, and on rearing them found that
they were a species of Mycetobia (Fig. 70; _a_, larva; _b_, pupa). The
larva is remarkable for having the abdominal segments divided into two
portions, the hinder much smaller than the anterior division. Its whole
length is a little over a third of an inch. The pupæ were found sticking
out in considerable numbers from the tree, being anchored by the little
spines at the tail. The head is square, ending in two horns, and the
body is straight and covered with spines, especially towards the end of
the tail. They were a fifth of an inch in length. The last of June the
flies appeared, somewhat resembling gnats, and about a line long. The
worms continued to infest the tree for six weeks, the flies remaining
either upon or near it.

[Illustration: 71. Mouth Parts of Tabanus.]

We now come to that terror of our equine friends, the Horse fly, Gad, or
Breeze fly. In its larval state, some species live in water, and in damp
places under stones and pieces of wood, and others in the earth away
from water, where they feed on animal, and, probably, on decaying
matter. Mr. B. D. Walsh found an aquatic larva of this genus, which,
within a short time, devoured eleven water snails. Thus at this stage of
existence, this fly, often so destructive, even at times killing our
horses, is beneficial. During the hotter parts of summer, and when the
sun is shining brightly, thousands of these Horse flies appear on our
marshes and inland prairies. There are many different kinds, over one
hundred species of the genus Tabanus alone, living in North America. Our
most common species is the "Green head," or Tabanus lineola. When about
to bite, it settles quietly down upon the hand, face or foot, it matters
not which, and thrusts its formidable lancet-like jaws deep into the
flesh. Its bite is very painful, as we can testify from personal
experience. We were told during the last summer that a horse, which
stood fastened to a tree in a field near the marshes at Rowley, Mass.,
was bitten to death by these Green heads; and it is known that horses
and cattle are occasionally killed by their repeated harassing bites. In
cloudy weather they do not fly, and they perish on the cool frosty
nights of September. The Timb, or Tsetze fly, is a species of this group
of flies, and while it does not attack man, plagues to death, and is
said to poison by its bite, the cattle in certain districts of the
interior of Africa, thus almost barring out explorers. On comparing the
mouth-parts of the Horse fly (Fig. 71, mouth of T. lineola), we have all
the parts seen in the mosquito, but greatly modified. Like the mosquito,
the females alone bite, the male Horse fly being harmless, and
frequenting flowers, living upon their sweets. The labrum (_lb_),
mandibles (_m_) and maxillæ (_mx_), are short, stiff and lancet-like,
and the maxillary palpi (_mp_; _a_, the five terminal joints of the
antennæ) are large, stout, and two-jointed. While the jaws (both maxillæ
and mandibles) are thrust into the flesh, the tongue (_l_) spreads
around the tube thus formed by the lancets, and pumps up the blood
flowing from the wound, by aid of the sucking stomach, or crop, being a
sac appended to the throat. Other Gad flies, but much smaller, though as
annoying to us in woods and fields, are the species of Golden eyed
flies, Chrysops, which fly and buzz interminably about our ears, often
taking a sudden nip. They plague cattle, settling upon them and drawing
their blood at their leisure.

[Illustration: 72. Carpet Fly.]

[Illustration: 73. Carpet Worm.]

We turn to a comparatively unknown insect, which has occasionally
excited some distrust in the minds of housekeepers. It is the carpet
fly, Scenopinus pallipes (Fig. 72), which, in the larva state, is found
under carpets, on which it is said to feed. The worm (Fig. 73) has a
long, white, cylindrical body, divided into twelve segments, exclusive
of the head, while the first eight abdominal segments are divided by a
transverse suture, so that there appear to be seventeen abdominal
segments, the sutures appearing too distinct in the cut. Mr. F. G.
Sanborn has reared the fly, here figured, from the worm. The larva also
lives in rotten wood; it is too scarce ever to prove very destructive in
houses. Either this or a similar fly was once found, we are told by a
scientific friend, in great numbers in a "rat" used in dressing a young
lady's hair; the worms were living upon the hair stuffing.

One of the most puzzling objects to the collector of shells or insects,
is the almost spherical larva of Microdon globosus (Fig. 74). It is
flattened and smooth beneath and seems to adhere to the under side of
stones, where it might be mistaken for a snail.

The Syrphus fly, or Aphis eater, deserves more than the passing notice
which we bestow upon it. The maggot (Fig. 75, in the act of devouring an
Aphis) is to be sought for established in a group of plant lice (Aphis),
which it seizes by means of the long extensible front part of the body.
The adult fly (Fig. 76) is gayly spotted and banded with yellow,
resembling closely a wasp. It frequents flowers.

[Illustration: 74. Microdon.]

[Illustration: 75. Syrphus Larva.] 76. Syrphus Fly.]

[Illustration: 77. Larva of Rat-tailed Fly. 78. Rat-tailed Fly and its
Pupa.]

The singular rat-tailed pupa-case of Eristalis (Fig. 77) lives in water,
and when in want of air, protrudes its long respiratory tube out into
the air. We present the figure of an allied fly, Merodon Bardus (Fig.
78; _a_, puparium, natural size). We will not describe at length the
fly, as the admirable drawings of Mr. Emerton cannot fail to render it
easily recognizable. The larva is much like the puparium or pupa case,
here figured, which closely resembles that of Eristalis, in possessing
along respiratory filament, showing that the maggot undoubtedly lives in
the water, and when desirous of breathing, protrudes the tube out of the
water, thus drawing in air enough to fill its internal respiratory tubes
(tracheæ). The Merodon Narcissa probably lives in the soil, or in rotten
wood, as the pupa-case has no respiratory tube, having instead a very
short, sessile, truncated tube, scarcely as long as it is thick. The
case itself is cylindrical, and rounded alike at each end.

[Illustration: 79. Human Bot Worm.]

We now come to the Bot flies, which are among the most extraordinary, in
their habits, of all insects. The history of the Bot flies is in brief
thus. The adult two-winged fly lays its eggs on the exterior of the
animal to be infested. They are conveyed into the interior of the host,
where they hatch, and the worm or maggot lives by sucking in the
purulent matter, caused by the irritation set up by its presence in its
host; or else the worm itself, after hatching, bores under the skin.
When fully grown, it quits the body and finishes its transformations to
the fly-state under ground. Many quadrupeds, from mice, squirrels, and
rabbits, up to the ox, horse, and even the rhinoceros, suffer from their
attacks, while man himself is not exempt. The body of the adult fly is
stout and hairy, and it is easily recognized by having the opening of
the mouth very small, the mouth-parts being very rudimentary. The larvæ
are, in general, thick, fleshy, footless grubs, consisting of eleven
segments, exclusive of the head, which are covered with rows of spines
and tubercles, by which they move about within the body, thus irritating
the animals in which they take up their abode. The breathing pores
(stigmata) open in a scaly plate at the posterior end of the body. The
mouth-parts (mandibles, etc.) of the subcutaneous larvæ consist of
fleshy tubercles, while in those species which live in the stomachs and
frontal sinuses of their host, they are armed with horny hooks.

[Illustration: 80. Horse Bot Fly.]

The larvæ attain their full size after moulting twice. Just before
assuming the pupa state, the maggot leaves its peculiar dwelling place,
descends into the ground and there becomes a pupa, though retaining its
larval skin, which serves as a protection to it, whence it is called a
"puparium."

Several well-authenticated instances are on record of a species of bot
fly inhabiting the body of man, in Central and South America, producing
painful tumors under the skin of the arm, legs and abdomen. It is still
under dispute whether this human bot fly is a true or accidental
parasite, the more probable opinion being that its proper host is the
monkey or dog. In Cayenne, this revolting grub is called the Ver macaque
(Fig. 79); in Para, Ura; in Costa Rica, Torcel; and in New Granada,
Gusano peludo, or Nuche. The Dermatobia noxialis, supposed to be the Ver
moyocuil of the inhabitants of Mexico and New Granada, lives beneath the
skin of the dog.

[Illustration: 81. Bot Fly of Ox, and Larva.]

[Illustration: 82. Sheep Bot.]

[Illustration: 83. Skin Bot Fly.]

The Bot fly of the horse, (Gastrophilus equi, Fig. 80 and larva), is
pale yellowish, spotted with red, with short, grayish, yellow hairs, and
the wings are banded with reddish. She lays her eggs upon the knees of
the horse. They are conveyed into the stomach, where the larva lives
from May until October, and when full grown are found hanging by their
mouth hooks on the edge of the rectum of the horse, whence they are
carried out in the excrement. The pupa state lasts for thirty or forty
days, and the perfect fly appears the next season, from June until
October.

The Bot fly of the ox (Hypoderma bovis, Fig. 81, and larva), is black
and densely hairy, and the thorax is banded with yellow and white. The
larva is found during the month of May, and also in summer, living in
tumors on the backs of cattle. When fully grown, which is generally in
July, they make their way out and fall to the ground, and live in the
pupa-case from twenty-six to thirty days, the fly appearing from May
until September. It is found all over the world. The Oestrus ovis, or
sheep Bot fly (Fig. 82, larva), is of a dirty ash color. The abdomen is
marbled with yellowish and white flecks, and is hairy at the end. This
species of Bot fly is larviparous, i.e., the eggs are hatched within the
body of the mother, the larvæ being produced alive. M. F. Brauer, of
Vienna, the author of the most thorough work we have on these flies,
tells me that he knows of but one other Bot fly (a species of
Cephanomyia) which produces living larvæ instead of eggs. The eggs of
certain other species of Bot flies do not hatch until three or four days
after they are laid. The larvæ of the sheep Bot fly live, during April,
May and June, in the frontal sinus of the sheep, and also in the nasal
cavity, whence they fall to the ground when fully grown. In twenty-four
hours they change to pupæ, and the flies appear during the summer.

We also figure the Cuterebra buccata (Fig. 83; _a_, side view,) which
resembles in the larval state the ox Bot fly. Its habits are not known,
though the young of other species infest the opossum, squirrel, hare,
etc., living in subcutaneous tumors.

[Illustration: The banded Lithacodes.]




CHAPTER VII.

THE HOUSE FLY AND ITS ALLIES.


[Illustration: 84. Mouth-parts of the House fly.]

The common House fly, Musca domestica, scarcely needs an introduction to
any one of our readers, and its countenance is so well known that we
need not present a portrait here. But a study of the proboscis of the
fly reveals a wonderful adaptability of the mouth-parts of this insect
to their uses. We have already noticed the most perfect condition of
these parts as seen in the horse fly. In the proboscis of the house fly
the hard parts are obsolete, and instead we have a fleshy tongue like
organ (Fig. 84), bent up beneath the head when at rest. The maxillæ are
minute, their palpi (_mp_) being single-jointed, and the mandibles (_m_)
are comparatively useless, being very short and small, compared with the
lancet-like jaws of the mosquito or horse fly. But the structure of the
tongue itself (labium, l) is most curious. When the fly settles upon a
lump of sugar or other sweet object, it unbends its tongue, extends it,
and the broad knob-like end divides into two broad, flat, muscular
leaves (_l_), which thus present a sucker-like surface, with which the
fly laps up liquid sweets. These two leaves are supported upon a
framework of tracheal tubes. In the cut given above, Mr. Emerton has
faithfully represented these modified trachæ, which end in hairs
projecting externally. Thus the inside of this broad fleshy expansion
is rough like a rasp, and as Newport states, "is easily employed by the
insect in scraping or tearing delicate surfaces. It is by means of this
curious structure that the busy house fly occasions much mischief to the
covers of our books, by scraping off the albuminous polish, and leaving
tracings of its depredations in the soiled and spotted appearance which
it occasions on them. It is by means of these also that it teases us in
the heat of summer, when it alights on the hand or face to sip the
perspiration as it exudes from, and is condensed upon, the skin."

[Illustration: 85. Larva; _a_, Pupa-case of House fly.]

[Illustration: 86. Larva of Flesh fly.]

Every one notices that house flies are most abundant around barns in
August and September, and it is in the ordure of stables that the early
stages of this insect are passed. No one has traced the transformations
of this fly in our country, but we copy from Bouché's work on the
transformations of insects, the rather rude figures of the larva (Fig.
85), and pupa-case (_a_) of the Musca domestica of Europe, which is
supposed to be our species. Bouché states that the larva is cylindrical,
rounded posteriorly, smooth and shining, fleshy, and yellowish white,
and four lines long. The pupa-case, or puparium, is dark reddish-brown,
and three lines in length. It remains in the pupa state from eight to
fourteen days. In Europe it is preyed upon by minute ichneumon flies
(Chalcids). The flesh fly, Musca Cæsar, or the Blue-bottle fly, feeds
upon decaying animal matter. Its larva (Fig. 86) is long, cylindrical,
the head being pointed, and the body conical, the posterior end being
squarely docked. The larva of a Sargus-like form which feeds on offal,
transforms into a flattened pupa-case (Fig. 87), provided with long,
scattered hairs. The House fly disappears in autumn, at the approach of
cold weather, though a few individuals pass through the winter,
hibernating in houses, and when the rooms are heated may often be seen
flying on the windows. Other species fly early in March, on warm days,
having hibernated under leaves, and the bark of trees, moss, etc. An
allied species, the M. vomitoria, is the Meat fly. Closely allied are
the parasitic species of Tachina, which live within the bodies of
caterpillars and other insects, and are among the most beneficial of
insects, as they prey on thousands of injurious caterpillars. Another
fly of this Muscid group, the Idia Bigoti, according to Coquerel and
Mondiere, produces in the natives of Senegal, hard, red, fluctuating
tumors, in which the larva resides.

[Illustration: 87. Larva of a Sargus-like fly.]

Many of the smaller Muscids mine leaves, running galleries within the
leaf, or burrowing in seeds or under the bark of plants. We have often
noticed blister-like swellings on the bark of the willow, which are
occasioned by a cylindrical, short, fleshy larva (Fig. 88_a_, much
enlarged), about a line in length, which changes to a pupa within the
old larval skin, assuming the form here represented (Fig. 88_b_), and
about the last of June changes to a small black fly (Fig. 88), which
Baron Osten Sacken refers doubtfully to the genus Lonchæa.

[Illustration: 86. Willow Blister fly.]

The Apple midge frequently does great mischief to apples after they are
gathered. Mr. F. G. Sanborn states that nine-tenths of the apple crop in
Wrentham, Mass., were destroyed by a fly supposed to be the Molobrus
mali, or Apple midge, described by Dr. Fitch. "The eggs were supposed to
have been laid in fresh apples, in the holes made by the Coddling moth
(Carpocapsa pomonella), whence the larvæ penetrated into all parts of
the apple, working small cylindrical burrows about one-sixteenth of an
inch in diameter." Mr. W. C. Fish has also sent me, from Sandwich,
Mass., specimens of another kind of apple worm, which he writes has been
very common in Barnstable county. "It attacks mostly the earlier
varieties, seeming to have a particular fondness for the old fashioned
Summer, or High-top Sweet. The larvæ (Fig. 89 _a_) enter the fruit
usually where it has been bored by the Apple worm (Carpocapsa), not
uncommonly through the crescent-like puncture of the curculio, and
sometimes through the calyx, when it has not been troubled by other
insects. Many of them arrive at maturity in August, and the fly soon
appears, successive generations of the maggots following until cold
weather. I have frequently found the pupæ in the bottom of barrels in a
cellar in the winter, and the flies appear in the spring. In the early
apples, the larvæ work about in every direction. If there be several in
an apple, they make it unfit for use. Apples that appear perfectly sound
when taken from the tree, will sometimes, if kept, be all alive with
them in a few weeks." Baron Osten Sacken informs me that it is a
Drosophila, "the species of which live in putrescent vegetable matter,
especially fruits."

[Illustration: 89. Apple Worm and its Larva.]

[Illustration: 90. Parent of the Cheese Maggot.]

[Illustration: 91. Pupa case of Wine-fly.]

An allied fly is the parent of the cheese maggot. The fly itself
(Piophila casei, Fig. 90) is black, with metallic green reflections, and
the legs are dark and paler at the knee-joints, the middle and hind pair
of tarsi being dark honey yellow. The Wine fly is also a Piophila, and
lives the life of a perpetual toper in old wine casks, and partially
emptied beer, cider and wine bottles, where, with its pupa-case (Fig.
91), it may be found floating dead in its favorite beverage.

[Illustration: 92. Bird Tick.]

We now come to the more degraded forms of flies which live parasitically
on various animals. We figure, from a specimen in the Museum of the
Peabody Academy of Science, the Bird tick (Ornithomyia, Fig. 92), which
lives upon the Great Horned Owl. Its body is much flattened, adapted for
its life under the feathers, where it gorges itself with the blood of
its host.

[Illustration: 93. The Horse Tick.]

Here belongs also the Horse tick (Hippobosca equina, Fig. 93). It is
about the size of the house fly, being black, with yellow spots on the
thorax. Verrill[4] says that "it attacks by preference those parts where
the hair is thinnest and the skin softest, especially under the belly
and between the hind legs. Its bite causes severe pain, and will
irritate the gentlest horses, often rendering them almost unmanageable,
and causing them to kick dangerously. When found, they cling so firmly
as to be removed with some difficulty, and they are so tough as not to
be readily crushed. If one escapes when captured, it will instantly
return to the horse, or, perchance, to the head of its captor, where it
is an undesirable guest. Another species sometimes infests the ox."

[Illustration: 94. Sheep Tick.]

[Illustration: 95. Bat Tick.]

In the wingless Sheep tick (Melophagus ovinus, Fig. 94, with the
pupa-case on the left), the body is wingless and very hairy, and the
proboscis is very long. The young are developed within the body of the
parent, until they attain the pupa state, when she deposits the pupa
case, which is nearly half as large as her abdomen. Other genera are
parasitic on bats; among them are the singular spider-like Bat ticks
(Nycteribia, Fig. 95), which have small bodies and enormous legs, and
are either blind, or provided with four simple eyes. They are of small
size, being only a line or two in length. Such degraded forms of Diptera
have a remarkable resemblance to the spiders, mites, ticks, etc. The
reader should compare the Nycteribia with the young six-footed moose
tick figured farther on. Another spider-like fly is the Chionea valga
(Fig. 96; and 97, larva of the European species), which is a degraded
Tipula, The latter genus standing near the head of the Diptera. The
Chionea, according to Harris, lives in its early, stages in the ground
like many other gnats, and is found early in the spring, sometimes
crawling over the snow. We have also figured and mentioned previously
(page 41) the Bee louse, Braula, another wingless spider-like fly.

[Illustration: 96. Spider fly.]

[Illustration: 97. Larva of Spider fly.]

The Flea is also a wingless fly, and is probably, as has been suggested
by an eminent entomologist, as Baron Osten Sacken informs us, a degraded
genus of the family to which Mycetobia belongs. Its transformations are
very unlike those of the fly ticks, and agree closely with the early
stages of Mycetophila, one of the Tipulid family. In its adult condition
the flea combines the characters of the Diptera, with certain features
of the grasshoppers and cockroaches, and the bugs. The body of the flea
(Fig. 98, greatly magnified; _a_, antennæ; _b_, maxillæ, and their
palpi, _c_; _d_, mandibles; the latter, with the labium, which is not
shown in the figure, forming the acute beak) is much compressed, and
there are minute wing-pads, instead of wings, present in some species.

[Illustration: 98. Flea, magnified.]

[Illustration: 99. Larva of Flea.]

Dr. G. A. Perkins, of Salem, has succeeded in rearing in considerable
numbers from the eggs, the larvæ of this flea. The larvæ (Fig. 99, much
enlarged; _a_, antenna; _b_, the terminal segments of the abdomen), when
hatched, are half a line in length. The body is long, cylindrical, and
pure white, with thirteen segments exclusive of the head, and provided
with rather long hairs. It is very active in its movements, and lives on
blood clots, remaining on unswept floors of out-houses, or in the straw
or bed of the animals they infest. In six days after the eggs are laid
the larvæ appear, and in a few days after leaving the egg they mature,
spin a rude cocoon, and change to pupæ, and the perfect insects appear
in about ten days. A good authority states that the human flea does not
exist in America. We never saw a specimen in this country.

A practical point is how to rid dogs of fleas. As a preventive measure,
we would suggest the frequent sweeping and cleansing of the floors of
their kennels, and renewing the straw or chips composing their
beds,--chips being the best material for them to sleep upon. Flea
afflicted dogs should be washed every few days in strong soapsuds, or
weak tobacco or petroleum water.

A writer in "Science-Gossip" recommends the "use of the Persian Insect
Destroyer, one package of which suffices for a good sized dog. The
powder should be well rubbed in all over the skin, or the dog, if small,
can be put into a bag previously dusted with the powder; in either case
the dog should be washed soon after."

[Illustration: 100. Chique.]

One of the most serious insect torments of the tropics of America is the
Sarcopsylla penetrans, called by the natives the Jigger, Chigoe, Bicho,
Chique, or Pique (Fig. 100, enlarged; a, gravid female, natural size).
The female, during the dry season, bores into the feet of the natives,
the operation requiring but a quarter of an hour, usually penetrating
under the nails, and lives there until her body becomes distended with
eggs, the hind-body swelling out to the size of a pea; her presence
often causes distressing sores. The Chigoe lays about sixty eggs,
depositing them in a sort of sac on each side of the external opening of
the oviduct. The young develop and feed upon the swollen body of the
parent flea until they mature, when they leave the body of their host
and escape to the ground. The best preventive is cleanliness and the
constant wearing of shoes or slippers when in the house, and of boots
when out of doors.

[Illustration: The Willow Gall Fly.]


CHAPTER VIII.

THE BORERS OF OUR SHADE TREES.


In no way can the good taste and public spirit of our citizens be better
shown than in the planting of shade trees. Regarded simply from a
commercial point of view one cannot make a more paying investment than
setting out an oak, elm, maple or other shade tree about his premises.
To a second generation it becomes a precious heirloom, and the planter
is duly held in remembrance for those finer qualities of heart and head,
and the wise forethought which prompted a deed simple and natural, but a
deed too often undone. What an increased value does a fine avenue of
shade trees give to real estate in a city? And in the country the single
stately elm rising gracefully and benignantly over the wayside cottage,
year after year like a guardian angel sending down its blessings of
shade, moisture and coolness in times of drought, and shelter from the
pitiless storm, recalls the tenderest associations of generation after
generation that go from the old homestead.

Occasionally the tree, or a number of them, sicken and die, or linger
out a miserable existence, and we naturally after failing to ascribe the
cause to bad soil, want of moisture or adverse atmospheric agencies,
conclude that the tree is infested with insects, especially if the bark
in certain places seems diseased. Often the disease is in streets
lighted by gas, attributed to the leakage of the gas. Such a case has
come up recently at Morristown, New Jersey. An elm was killed by the Elm
borer (Compsidea tridentata), and the owner was on the point of suing
the Gas Company for the loss of the tree from the supposed leakage of a
gas pipe. While the matter was in dispute, a gentleman of that city took
the pains to peel off a piece of the bark and found, as he wrote me,
"great numbers of the larvæ of this beetle in the bark and between the
bark and the wood, while the latter is 'tattooed' with sinuous grooves
in every direction and the tree is completely girdled by them in some
places. There are three different sizes of the larvæ, evidently one, two
and three years old, or more properly six, eighteen and thirty months
old." The tree had to be cut down.

Dr. Harris, in his "Treatise on Injurious Insects," gives an account of
the ravages of this insect, which we quote: "On the 19th of June, 1846,
Theophilus Parsons, Esq., sent me some fragments of bark and insects
which were taken by Mr. J. Richardson from the decaying elms on Boston
Common, and among the insects I recognized a pair of these beetles in a
living state. The trees were found to have suffered terribly from the
ravages of these insects. Several of them had already been cut down, as
past recovery; others were in a dying state, and nearly all of them were
more or less affected with disease or premature decay. Their bark was
perforated, to the height of thirty feet from the ground, with numerous
holes, through which insects had escaped; and large pieces had become so
loose, by the undermining of the grubs, as to yield to slight efforts,
and come off in flakes. The inner bark was filled with burrows of the
grubs, great numbers of which, in various stages of growth, together
with some in the pupa state, were found therein; and even the surface of
the wood, in many cases, was furrowed with their irregular tracks. Very
rarely did they seem to have penetrated far into the wood itself; but
their operations were mostly confined to the inner layers of the bark,
which thereby became loosened from the wood beneath. The grubs rarely
exceed three-quarters of an inch in length. They have no feet, and they
resemble the larvæ of other species of Saperda, except in being rather
more flattened. They appear to complete their transformations in the
third year of their existence.

"The beetles probably leave their holes in the bark during the month of
June and in the beginning of July, for, in the course of thirty years, I
have repeatedly taken them at various dates, from the fifth of June to
the tenth of July. It is evident, from the nature and extent of their
depredations, that these insects have alarmingly hastened the decay of
the elm trees on Boston Mall and Common, and that they now threaten
their entire destruction. Other causes, however, have probably
contributed to the same end. It will be remembered that these trees
have greatly suffered, in past times, from the ravages of canker-worms.
Moreover, the impenetrable state of the surface soil, the exhausted
condition of the subsoil, and the deprivation of all benefit from the
decomposition of accumulated leaves, which, in a state of nature, the
trees would have enjoyed, but which a regard for neatness has
industriously removed, have doubtless had no small influence in
diminishing the vigor of the trees, and thus made them fall
unresistingly a prey to insect devourers. The plan of this work
precludes a more full consideration of these and other topics connected
with the growth and decay of these trees; and I can only add, that it
may be prudent to cut down and burn all that are much infested by the
borers."

[Illustration: 101. Elm Tree Beetle.]

The Three-toothed Compsidea (Fig. 101), is a rather flat-bodied, dark
brown beetle, with a rusty red curved line behind the eyes, two stripes
on the thorax, and a three-toothed stripe on the outer edge of each wing
cover. It is about one-half an inch in length.

[Illustration: 102. Elm Tree Borer.]

The larva (Fig. 102) is white, subcylindrical, a little flattened, with
the lateral fold of the body rather prominent; the end of the body is
flattened, obtuse, and nearly as wide at the end as at the first
abdominal ring. The head is one-half as wide as the prothoracic ring,
being rather large. The prothoracic ring, or segment just behind the
head, is transversely oblong, being twice as broad as long; there is a
pale dorsal corneous transversely oblong shield, being about two-thirds
as long as wide, and nearly as long as the four succeeding segments;
this plate is smooth, except on the posterior half, which is rough, with
the front edge irregular and not extending far down the sides. Fine
hairs arise from the front edge and side of the plate, and similar hairs
are scattered over the body and especially around the end. On the upper
side of each segment is a transversely oblong ovate roughened area, with
the front edge slightly convex, and the hinder slightly arcuate. On the
under side of each segment are similar rough horny plates, but arcuate
in front, with the hinder edge straight.

It differs from the larva of the Linden tree borer (Saperda vestita) in
the body being shorter, broader, more hairy, with the tip of the abdomen
flatter and more hairy. The prothoracic segment is broader and flatter,
and the rough portion of the dorsal plates is larger and less
tranversely ovate. The structure of the head shows that its generic
distinctness from Saperda is well founded, as the head is smaller and
flatter, the clypeus being twice as large, and the labrum broad and
short, while in S. vestita it is longer than broad. The mandibles are
much longer and slenderer, and the antennæ are much smaller than in S.
vestita.

[Illustration: 103. Linden Tree Beetle.]

[Illustration: 104. Linden Tree Borer.]

The Linden tree borer (Fig. 103) is a greenish snuff-yellow beetle, with
six black spots near the middle of the back; and it is about
eight-tenths of an inch in length, though often smaller. The beetles,
according to Dr. Paul Swift, as quoted by Dr. Harris, were found (in
Philadelphia) upon the small branches and leaves on the 28th day of May,
and it is said that they come out as early as the first of the month,
and continue to make their way through the back of the trunk and large
branches during the whole of the warm season. They immediately fly into
the top of the tree, and there feed upon the epidermis of the tender
twigs, and the petioles of the leaves, often wholly denuding the latter,
and causing the leaves to fall. They deposit their eggs, two or three in
a place, upon the trunk or branches especially about the forks, making
slight incisions or punctures for their reception with their strong
jaws. As many as ninety eggs have been taken from a single beetle. The
grubs (Fig. 104, _e_; _a_, enlarged view of the head seen from above;
_b_, the under view of the same: _c_, side view, and _d_, two rings of
the body enlarged), hatched from these eggs, undermine the bark to the
extent of six or eight inches, in sinuous channels, or penetrate the
solid wood an equal distance. It is supposed that three years are
required to mature the insect. Various expedients have been tried to
arrest their course, but without effect. A stream, thrown into the tops
of trees from the hydrant, is often used with good success to dislodge
other insects; but the borer-beetles, when thus disturbed, take wing and
hover over the trees till all is quiet, and then alight and go to work
again. The trunks and branches of some of the trees have been washed
over with various preparations without benefit. Boring the trunk near
the ground and putting in sulphur and other drugs, and plugging, have
been tried with as little effect.

[Illustration: 105. Poplar Tree Borer.]

The city of Philadelphia has suffered grievously from this borer.

[Illustration: 106. Broad-necked Prionus.]

Dr. Swift remarks, in 1844, that "the trees in Washington and
Independence Squares were first observed to have been attacked about
seven years ago. Within two years it has been found necessary to cut
down forty-seven European lindens in the former square alone, where
there now remain only a few American lindens, and these a good deal
eaten." In New England this beetle should be looked for during the first
half of June.

[Illustration: 107. Larva of the Plain Saperda.]

The Poplar tree is infested by an other species of Saperda (S.
calcarata). This is a much larger beetle than those above mentioned,
being an inch or a little more in length. It is grey, irregularly
striped, with ochre, and the wing-covers end in a sharp point. The grub
(Fig. 105 _a_; _b_, top view of the head; _e_, under side) is about two
inches long and whitish yellow. It has, with that of the Broad-necked
Prionus (P. laticollis of Drury, Fig. 106, adult and pupa), as Harris
states, "almost entirely destroyed the Lombardy poplar in this vicinity"
(Boston). It bores in the trunks, and the beetle flies by night in
August and September. We also figure the larva of another borer (Fig.
107 _c_; _a_, top view of the head; _b_, under side; _e_, dorsal view of
an abdominal segment; _d_, end of the body, showing its peculiar form),
the Saperda inornata of Say, the beetle of which is black, with ash gray
hairs, and without spines on the wing-covers. It is much smaller than
any of the foregoing species, being nine-twentieths of an inch in
length. Its habits are not known. We also figure the Locust and Hickory
borer (Fig. 108; _a_, larva; _b_, pupa), which has swept off the locust
tree from New England. The beautiful yellow banded beetles are very
abundant on the flowers of the golden rod in September.

[Illustration: 108. Locust Borer.]

FOOTNOTES:

[Footnote 4: The External and Internal Parasites of Man and Domestic
Animals. By Prof. A. E. Verrill, 1870. We are indebted to the author for
the use of this and the figures of the Bot fly of the horse, the turkey,
duck and hog louse, the Cattle tick, the itch insect and mange insect of
the horse.]




CHAPTER IX.

CERTAIN PARASITIC INSECTS.


The subject of our discourse is not only a disagreeable but too often a
painful one. Not only is the mere mention of the creature's name of
which we are to speak tabooed and avoided by the refined and polite, but
the creature itself has become extinct and banished from the society of
the good and respectable. Indeed under such happy auspices do a large
proportion of the civilized world now live that their knowledge of the
habits and form of a louse may be represented by a blank. Not so with
some of their great-great-grandfathers and grandmothers, if history,
sacred and profane, poetry,[5] and the annals of literature testify
aright; for it is comparatively a recent fact in history that the louse
has awakened to find himself an outcast and an alien. Among savage
nations of all climes, some of which have been dignified with the apt,
though high sounding name of Phthiriophagi, and among the Chinese and
other semi-civilized peoples, these lords of the soil still flourish
with a luxuriance and rankness of growth that never diminishes, so that
we may say without exaggeration that certain mental traits and fleshly
appetites induced by their consumption as an article of food may have
been created, while a separate niche in our anthropological museums is
reserved for the instruments of warfare, both offensive and defensive,
used by their phthiriophagous hunters. Then have we not in the very
centres of civilization the poor and degraded, which are most faithfully
attended lay these revolting satellites!

But bantering aside, there is no more engaging subject to the naturalist
than that of animal parasites. Consider the great proportion of animals
that gain their livelihood by stealing that of others. While a large
proportion of plants are more or less parasitic, they gain, thereby in
interest to the botanist, and many of them are eagerly sought as the
choicest ornaments of our conservatories. Not so with their zoölogical
confréres. All that is repulsive and uncanny is associated with them,
and those who study them, though perhaps among the keenest intellects
and most industrious observers, speak of them without the limits of
their own circle in subdued whispers or under a protest, and their works
fall under the eyes of the scantiest few. But the study of animal
parasites has opened up new fields of research, all bearing most
intimately on those two questions that ever incite the naturalist to the
most laborious and untiring diligence--what is life and its origin? The
subjects of the alternation of generations, or parthenogenesis, of
embryology and biology, owe their great advance, in large degree, to the
study of such animals as are parasitic, and the question whether the
origin of species be due to creation by the action of secondary laws or
not, will be largely met and answered by the study of the varied
metamorphoses and modes of growth, the peculiar modification of organs
that adapt them to their strange modes of life, and the consequent
variation in specific characters so remarkably characteristic of those
animals living parasitically upon others.[6]

With these considerations in view surely a serious, thoughtful, and
thorough study of the louse, in all its varieties and species, is
neither belittling nor degrading, nor a waste of time. We venture to
say, moreover, that more light will be thrown on the classification and
morphology of insects by the study of the parasitic species, and other
degraded, wingless forms that do not always live parasitically,
especially of their embryology and changes after leaving the egg, than
by years of study of the more highly developed insects alone. Among
Hymenoptera the study of the minute Ichueumons, such as the
Proctotrupids and Chalcids, especially the egg-parasites; among moths
the study of the wingless canker-worm moth and Orgyla; among Diptera the
flea, bee louse, sheep tick, bat tick, and other wingless flies; among
Coleoptera, the Meloë, and singular Stylops and Xenos; among Neuroptera,
the snow insect, Boreus, the Podura (Fig. 109) and Lepisma, and
especially the hemipterous lice, will throw a flood of light on these
prime subjects in philosophical entomology.

[Illustration: 109. Podura.]

Without farther apology, then, and very dependent on the labors of
others for our information, we will say a few words on some interesting
points in the natural history of lice. In the first place, how does the
louse bite? It is the general opinion among physicians, supported by
able entomologists, that the louse has jaws, and bites. But while the
bird lice (Mallophaga) do have biting jaws, whence the Germans call them
skin-eaters (_pelzfresser_), the mouth parts of the genus Pediculus, or
true louse, resemble in their structure those of the bed-bug (Fig. 110),
and other Hemiptera. In its form the louse closely resembles the
bed-bug, and the two groups of lice, the Pediculi and Mallophaga, should
be considered as families of Hemiptera, though degraded and at the base
of the hemipterous series. The resemblance is carried out in the form of
the egg, the mode of growth of the embryo, and the metamorphosis of the
insect after leaving its egg.

[Illustration: 110. Bed-bug.]

Schiödte, a Danish entomologist, has, it seems to us, forever settled
the question as to whether the louse bites the flesh or sucks blood, and
decides a point interesting to physicians, _i.e._, that the loathsome
disease called phthiriasis is a nonentity. From this source not only
many living in poverty and squalor are said to have died, but also men
of renown, among whom Denny in his work on the Anoplura, or lice, of
Great Britain, mentions the name of "Pheretima, as recorded by
Herodotus, Antiochus Epiphanes, the Dictator Sylla, the two Herods, the
Emperor Maximian, and Phillip the Second." Schiödte, in his essay "On
Phthirius, and on the Structure of the Mouth in Pediculus" (Annals and
Magazine of Natural History, 1866, page 213), says that these statements
will not bear examination, and that this disease should be placed on the
"retired list," for such a malady is impossible to be produced by simply
blood-sucking animals, and that they are only the disgusting attendants
on other diseases. Our author thus describes the mouth parts of the
louse.

"Lice are no doubt to be regarded as bugs, simplified in structure and
lowered in animal life in accordance with their mode of living as
parasites, being small, flattened, apterous, myopic, crawling and
climbing, with a conical head, moulded as it were to suit the rugosities
of the surface they inhabit, provided with a soft, transversely furrowed
skin, probably endowed with an acute sense of feeling, which can guide
them in that twilight in which their mode of life places them. The
peculiar attenuation of the head in front of the antennæ at once
suggests to the practised eye the existence of a mouth adapted for
suction. This mouth differs from that of the Hemiptera (bed-bug, etc.)
generally, in the circumstance that the labium is capable of being
retracted into the upper part of the head, which therefore presents a
little fold, which is extended when the labium is protruded. In order to
strengthen this part, a flat band of chitine is placed on the under
surface, just as the shoemaker puts a small piece of gutta-percha into
the back of an India-rubber shoe; as, however, the chitine is not very
elastic, this band is rather thinner in the middle, in order that it may
bend and fold a little when the skin is not extended by the lower lip.
The latter consists, as usual, of two hard lateral pieces, of which the
fore ends are united by a membrane so that they form a tube, of which
the interior covering is a continuation of the elastic membrane in the
top of the head; inside its orifice there are a number of small hooks,
which assume different positions according to the degree of protrusion;
if this is at its highest point the orifice is turned inside out, like a
collar, whereby the small hooks are directed backwards, so that they can
serve as barbs. These are the movements which the animal executes after
having first inserted the labium through a sweat-pore. When the hooks
have got a firm hold, the first pair of setæ (the real mandibles
transformed) are protruded; these are, towards their points, united by a
membrane so as to form a closed tube, from which, again, is inserted the
second pair of setæ, or maxillæ, which in the same manner are
transformed into a tube ending in four small lobes placed crosswise. It
follows that when the whole instrument is exserted, we perceive a long
membranous flexible tube hanging down from the labium, and along the
walls of this tube the setiform mandibles and maxillæ in the shape of
long narrow bands of chitine. In this way the tube of suction can be
made longer or shorter as required, and easily adjusted to the thickness
of the skin in the particular place where the animal is sucking, whereby
access to the capillary system is secured at any part of the body. It is
apparent, from the whole structure of the instrument, that it is by no
means calculated on being used as a sting, but is rather to be compared
to a delicate elastic probe, in the use of which the terminal lobes
probably serve as feelers. As soon as the capillary system is reached,
the blood will at once ascend into the narrow tube, after which the
current is continued with increasing rapidity by means of the pulsation
of the pumping ventricle and the powerful peristaltic movement of the
digestive tube."

[Illustration:[7]111. Mouth of the Louse.]

If we compare the form of the louse (Fig. 112, Pediculus capitis, the
head louse; Fig. 113, P. vestimenti, the body louse) with the young
bed-bug as figured by Westwood (Modern Classification of Insects, ii,.p.
475) we shall see a very close resemblance, the head of the young Cimex
being proportionally larger than in the adult, while the thorax is
smaller, and the abdomen is more ovate, less rounded; moreover the body
is white and partially transparent.

[Illustration: 113. Body Louse.]

[Illustration: 112. Head Louse.]

Under a high power of the microscope specimens treated with diluted
potash show that the mandibles and maxillæ arise near each other in the
middle of the head opposite the eyes, their bases slightly diverging.
Thence they converge to the mouth, over which they meet, and beyond are
free, being hollow, thin bands of chitine, meeting like the maxillæ, or
tongue, of butterflies to form a hollow tube for suction. The mandibles
each suddenly end in a curved, slender filament, which is probably used
as a tactile organ to explore the best sites in the flesh of their
victim for drawing blood. On the other hand the maxillæ, which are much
narrower than the mandibles, become rounded towards the end, bristle
like, and tipped with numerous exceedingly fine barbs, by which the bug
anchors itself in the flesh, while the blood is pumped through the
mandibles. The base of the large, tubular labium, or beak, which
ensheathes the mandibles and maxillæ, is opposite the end of the clypeus
or front edge of the upper side of the head, and at a distance beyond
the mouth equal to the breadth of the labium itself. The labium, which
is divided into three joints, becomes flattened towards the tip, which
is square, and ends in two thin membranous lobes, probably endowed with
a slight sense of touch. On comparing these parts with those of the
louse, it will be seen how much alike they are with the exception of the
labium, a very variable organ in the Hemiptera. From the long sucker of
the Pediculus, to the stout chitinous jaws of the Mallophaga, or bird
lice, is a sudden transition, but on comparing the rest of the head and
body it will be seen that the distinction only amounts to a family one,
though Burmeister placed the Mallophaga among the Orthoptera
(grasshoppers and crickets) on account of the mandibles being adapted
for biting. It has been a common source of error to depend too much upon
one or a single set of organs. Insects have been classified on
characters drawn from the wings, or the number of the joints of the
tarsi, or the form of the mouth parts. We must take into account in
endeavoring to ascertain the limits of natural groups, as the internal
anatomy and the embryology and metamorphosis of insects, before we can
hope to obtain a natural classification.

The family of bird lice is a very extensive one, embracing many genera,
and several hundred species. One or more species infest the skin of all
our domestic and wild mammals and birds, some birds sheltering beneath
their feathers four or five species of lice. Before giving a hasty
account of some of our more common species; we will give a sketch of the
embryological history of the lice, with special reference to the
structure of the mouth parts.

[Illustration: 114. Embryo of the Louse.]

[Illustration: 115. Mouth Parts of the Louse.]

The eggs (Fig. 114, egg of the head louse) are long, oval, somewhat
pear-shaped, with the hinder end somewhat pointed, while the anterior
end is flattened, and bears little conical micropyles (_m_, minute
orifices for the passage of the spermatozoa into the egg), which vary in
form in the different species and genera; the opposite end of the egg is
provided with a few bristles. The female attaches her eggs to the hairs
or feathers of her host.

[Illustration: 116. Mouth Parts of the Louse.]

[Illustration: 118. Mouth Parts of Louse.]

[Illustration: 117. Mouth Parts of Louse.]

After the egg has been fertilized by the male, the blastoderm, or
primitive skin, forms, and subsequently two layers, or embryonal
membranes, appear; the outer is called the amnion (Fig. 114, _am_),
while the inner visceral membrane (_db_) partially wraps the rude form
of the embryo in its folds. The head (_vk_) of the embryo is now
directed towards the end of the egg on which the hairs are situated;
afterwards the embryo revolves on its axis and the head lies next to the
opposite end of the egg. Eight tubercles bud out from the under side of
the head, of which the foremost and longest are the antennæ (_as_),
those succeeding are the mandibles, maxillæ, and second maxillæ, or
labium. Behind them arise six long, slender tubercles forming the legs,
and the primitive streak rudely marks the lower wall of the thorax and
abdomen not yet formed. Figure 115 represents the head and mouth parts
of the embryo of the same louse; _vk_ is the forehead, or clypeus;
_ant_, the antennæ; _mad_, the mandibles; _max_1, the
first pair of maxillæ, and _max_^2, the second pair
of maxillæ, or labium. Figure 116 represents the mouth parts of the
same insect a little farther advanced, with the jaws and labium
elongated and closely folded together. Figure 117 represents the same
still farther advanced; the mandibles (_mad_) are sharp, and resemble
the jaws of the Mallophaga; and the maxillæ (_max_^1) and labium
(_max_^2) are still large, while afterwards the labium becomes nearly
obsolete. Figure 118 represents a front view of the mouth parts of a
bird louse, Goniodes; _lb_, is the upper lip, or labrum, lying under the
clypeus; _mad_, the mandibles; max, the maxillæ; _l_, the lyre-formed
piece; and _pl_, the "plate."

[Illustration: 119. Louse of Cow.]

We will now describe some of the common species of lice found on a few
of our domestic animals, and the mallophagous parasites occurring on
certain mammals and birds. The family Pediculina, or true lice, is
higher than the bird lice, their mouth parts, as well as the structure
of the head, resembling the true Hemiptera, especially the bed bug. The
clypeus, or front of the head, is much smaller than in the bird lice,
the latter retaining the enlarged forehead of the embryo, it being in
some species half as large as the rest of the head.

All of our domestic mammals and birds are plagued by one or more species
of lice. Figure 119 represents the Hæmatopinus vituli, which is brownish
in color. As the specimen figured came from the Burnett collection of
the Boston Society of Natural History, together with those of the goat
louse, the louse of the common fowl, and of the cat, they are
undoubtedly naturalized here. Quite a different species is the louse of
the hog (H. suis, Fig. 120).

[Illustration: 120. Louse of Hog.]

The remaining parasites belong to the skin-biting lice, or Mallophaga,
and I will speak of the several genera referred to in their natural
order, beginning with the highest form and that which is nearest allied
to Pediculus.

[Illustration: 121. Louse of Domestic Fowl.]

The common barn-yard fowl is infested by a louse that we have called
Goniocotes Burnettii (Fig. 121), in honor of the late Dr. W. I. Burnett,
a young and talented naturalist and physiologist, who paid more
attention than any one else in this country to the study of these
parasites, and made a large collection of them, now in the museum of the
Boston Society of Natural History. It differs from the G. hologaster of
Europe, which lives on the same bird, in the short second joint of the
antennæ, which are also stouter; and in the long head, the clypeus being
much longer and more acutely rounded; while the head is less hollowed
out at the insertion of the antennæ. The abdomen is oval, and one-half
as wide as long, with transverse, broad, irregular bands along the edges
of the segments. The mandibles are short and straight, two toothed. The
body is slightly yellowish, and variously streaked and banded with
pitchy black. The duck is infested by a remarkably slender form (Fig.
122, Philopterus squalidus). Figure 123 represents the louse of the cat,
and another species (Fig. 124) of the same genus (Trichodes) lives upon
the goat.

The most degraded genus is Gyropus. Mr. C. Cook has found Gyropus ovalis
of Europe abundant on the Guinea pig. A species is also found on the
porpoise; an interesting fact, as this is the only insect we know of
that lives parasitically on any marine animal.

[Illustration: 122. Duck Louse.]

The genus Goniodes (Fig. 125, G. stylifer, the turkey louse) is of great
interest from a morphological and developmental point of view, as the
antennæ are described and figured by Denny as being "in the males
cheliform (Fig. 126, _a_, male; _b_, female); the first joint being very
large and thick, the third considerably smaller, recurved towards the
first, and forming a claw, the fourth and fifth very small, arising
from the back of the third." He farther remarks, that "the males of this
[which lives on the turkey] and all the other species of Goniodes, use
the first and third joints of the antennæ with great facility, acting
the part of a finger and thumb." The antennæ of the females are of the
ordinary form. This hand-like structure, is, so far as we know, without
a parallel among insects, the antennæ of the Hemiptera being almost
uniformly filiform, and from two to nine-jointed. The design of this
structure is probably to enable the male to grasp its consort and also
perhaps to cling to the feathers, and thus give it a superiority over
the weaker sex in its advances towards courtship. Why is this advantage
possessed by the males of this genus alone? The world of insects, and of
animals generally abounds in such instances, though existing in other
organs, and the developmentist dimly perceives in such departures from a
normal type of structure, the origin of new generic forms, whether due
at first to a seemingly accidental variation, or, as in this instance,
perhaps, to long use as prehensile organs through successive generations
of lice having the antennæ slightly diverging from the typical
condition, until the present form has been developed. Another generation
of naturalists will perhaps unanimously agree that the Creator has thus
worked through secondary laws, which many of the naturalists of the
present day are endeavoring, in a truly scientific and honest spirit of
inquiry, to discover.

[Illustration: 124. Louse of the Goat.]

[Illustration: 123. Louse of the Cat.]

In their claw or leg-like form these male antennæ also repeat in the
head, the general form of the legs, whose prehensile and grasping
functions they assume. We have seen above that the appendages of the
head and thorax are alike in the embryo, and the present case is an
interesting example of the unity of type of the jointed appendages of
insects, and articulates generally.

[Illustration: 120. Antennæ of Goniodes.]

Another point of interest in these degraded insects is, that the process
of degradation begins either late in the life of the embryo or during
the changes from the larval to the adult, or winged state. An instance
of the latter may be observed in the wingless female of the canker worm,
so different from the winged male; this difference is created after the
larval stage, for the caterpillars of both sexes are the same, so far as
we know. So with numerous other examples among the moths. In the louse,
the embryo, late in its life, resembles the embryos of other insects,
even Corixa, a member of a not remotely allied family. But just before
hatching the insect assumes its degraded louse physiognomy. The
developmentist would say that this process of degradation points to
causes acting upon the insect just before or immediately after birth,
inducing the retrogression and retardation of development, and would
consider it as an argument for the evolution of specific forms by causes
acting on the animal while battling with its fellows in the struggle for
existence, and perhaps consider that the metamorphoses of the animal
within the egg are due to a reflex action of the modes of life of the
ancestors of the animal on the embryos of its descendants.

[Illustration: 125. The Turkey Louse.]

FOOTNOTES:

[Footnote 5:

  Ha! whare ye gaun, ye crowlin ferlie!
  Your impudence protects you sairly:
  I canna say but ye struift rarely,
      Owre gauze and lace;
  Tho' faith, I fear ye dine but sparely
      On sic a place.

  Ye ugly, creepin, blastic wormer,
  Detested, shunn'd by saunt and sinner,
  How dare ye set your fit upon her
      Sae fine a lady!
  Gae somewhere else and seek your dinner
      On some poor body.

(To a Louse.--Burns.)]

[Footnote 6: We notice while preparing this article that a journal of
Parasitology has for some time been issued in Germany--that favored land
of specialists. It is the "Zeitschrift fur Parasitenkunde," edited by
Dr. E. Hallier and F A. Zurn. 8vo, Jena.]

[Footnote 7: Figure 111 represents the parts of the mouth in a large
specimen of _Pediculus_ vestimenti, entirely protruding, and seen from
above, magnified one hundred and sixty times; aa, the summit of the head
with four bristles on each side; _bb_, the chitinous band, and _c_, the
hind part of the lower lip, such as they appear through the skin by
strong transmitted light; _dd_, the foremost protruding part of the
lower lip (the haustellum); _ee_, the hooks turned outwards; _f_, the
inner tube of suction, slightly bent and twisted; the two pairs of jaws
are perceived on the outside as thin lines; a few blood globules are
seen in the interior of the tube.]




CHAPTER X.

THE DRAGON FLY.


Were we to select from among the insects a type of all that is savage,
relentless, and bloodthirsty, the Dragon fly would be our choice. From
the moment of its birth until its death, usually a twelve-month, it
riots in bloodshed and carnage. Living beneath the waters perhaps eleven
months of its life, in the larva and pupa states, it is literally a
walking pitfall for luckless aquatic insects; but when transformed into
a fly, ever on the wing in pursuit of its prey, it throws off all
concealment, and reveals the more unblushingly its rapacious character.

Not only do its horrid visage and ferocious bearing frighten children,
who call it the "Devil's Darning-needle," but it even distresses older
persons, so that its name has become a byword. Could we understand the
language of insects, what tales of horror would be revealed! What
traditions, sagas, fables, and myths must adorn the annals of animal
life regarding this Dragon among insects!

To man, however, aside from its bad name and its repulsive aspect, which
its gay trappings do not conceal, its whole life is beneficent. It is a
scavenger, being like that class ugly and repulsive, and holding
literally, among insects, the lowest rank in society. In the water, it
preys upon young mosquitoes and the larvæ of other noxious insects. It
thus aids in maintaining the balance of life, and cleanses the swamps of
miasmata, thus purifying the air we breathe. During its existence of
three or four weeks above the waters, its whole life is a continued good
to man. It hawks over pools and fields and through gardens, decimating
swarms of mosquitoes, flies, gnats, and other baneful insects. It is a
true Malthus' delight, and, following that sanguinary philosopher, we
may believe that our Dragon fly is an entomological Tamerlane or
Napoleon sent into the world by a kind Providence to prevent too close a
jostling among the myriads of insect life.

We will, then, conquer our repugnance to its ugly looks and savage mien,
and contemplate the hideous monstrosity,--as it is useless to deny that
it combines the graces of the Hunchback of Notre Dame and Dickens'
Quilp, with certain features of its own,--for the good it does in
Nature.

Even among insects, a class replete with forms the very incarnation of
ugliness and the perfection of all that is hideous in nature, our Dragon
fly is most conspicuous. Look at its enormous head, with its beetling
brows, retreating face, and heavy under jaws,--all eyes and teeth,--and
hung so loosely on its short, weak neck, sunk beneath its enormous
hunchback,--for it is wofully round-shouldered,--while its long, thin
legs, shrunken as if from disease, are drawn up beneath its breast, and
what a hobgoblin it is!

Its gleaming wings are, however, beautiful objects. They form a broad
expanse of delicate parchment-like membrane drawn over an intricate
network of veins. Though the body is bulky, it is yet light, and easily
sustained by the wings. The long tail undoubtedly acts as a rudder to
steady its flight.

These insects are almost universally dressed in the gayest colors. The
body is variously banded with rich shades of blue, green, and yellow,
and the wings give off the most beautiful iridescent and metallic
reflections.

During July and August the various species of Libellula and its allies
most abound. The eggs are attached loosely in bunches to the stems of
rushes and other water-plants. In laying them, the Dragon fly, according
to Mr. P. R. Uhler's observations, "alights upon water-plants, and,
pushing the end of her body below the surface of the water, glues a
bunch of eggs to the submerged stem or leaf. Libellula auripennis I have
often seen laying eggs, and I think I was not deceived in my observation
that she dropped a bunch of eggs into the open ditch while balancing
herself just a little way above the surface of the water. I have, also,
seen her settled upon the reeds in brackish water with her abdomen
submerged in part, and there attaching a cluster of eggs. I feel pretty
sure that L. auripennis does not always deposit the whole of her eggs at
one time, as I have seen her attach a cluster of not more than a dozen
small yellow eggs. There must be more than one hundred eggs in one of
the large bunches. The eggs of some of the Agrions are bright
apple-green, but I cannot be sure that I have ever seen them in the very
act of oviposition. They have curious habits of settling upon leaves and
grass growing in the water, and often allow their abdomens to fall below
the surface of the water; sometimes they fly against the surface, but I
never saw what I could assert to be the projecting of the eggs from the
body upon plants or into the water. The English entomologists assert
that the female Agrion goes below the surface to a depth of several
inches to deposit eggs upon the submerged stems of plants." The Agrions,
however, according to Lucaze Duthiers, a French anatomist, make, with
the ovipositor, a little notch in the plant upon which they lay their
eggs.

[Illustration: 127. Under side of head of Diplax, with the labium or
mask fully extended. _x_, _x_', _x_''the three subdivisions of the
labium. _y_, the maxillæ or second pair of jaws.]

These eggs soon hatch, probably during the heat of summer. The larva is
very active in its habits, being provided with six legs, attached to the
thorax, on the back of which are the little wing-pads, or rudimentary
wings. The large head is provided with enormous eyes, while a pair of
simple, minute eyelets (ocelli) are placed near the origin of the small
bristle-like feelers, or antennæ. Seen from beneath, instead of the
formidable array of jaws and accessory organs commonly observed in most
carnivorous larvæ, we see nothing but a broad, smooth mask covering the
lower part of the face; as if from sheer modesty our young Dragon fly
was endeavoring to conceal a gape. But wait a moment. Some unwary insect
comes within striking distance. The battery of jaws is unmasked, and
opens upon the victim. This mask (Fig. 127) is peculiar to the young,
or larva and pupa of the Dragon fly. It is the labium, or under lip
greatly enlarged, and armed at the broad spoon-shaped extremity (Fig.
127, _x_) with two sharp hooks, adapted for seizing and retaining its
prey. At rest, the terminal half is so bent up as to conceal the face,
and thus the creature crawls about, to all appearance, the most innocent
and lamb-like of insects.

[Illustration: 128. Abdominal valves; _a_, side view.]

Not only does the immature Dragon fly walk over the bottom of the pool
or stream it inhabits, but it can also leap for a considerable distance,
and by a most curious contrivance. By a syringe-like apparatus lodged in
the end of the body, it discharges a stream of water for a distance of
two or three inches behind it, thus propelling the insect forwards. This
apparatus combines the functions of locomotion and respiration. There
are, as usual, two breathing pores (stigmata) on each side of the
thorax. But the process of breathing seems to be mostly carried on in
the tail. The tracheæ are here collected in a large mass, sending their
branches into folds of membrane lining the end of the alimentary canal,
and which act like a piston to force out the water. The entrance to the
canal is protected by three to five triangular horny valves (Fig. 128,
9, 10, 128 _a_, side view), which open and shut at will. When open, the
water flows in, bathing the internal gill-like organs, which extract the
air from the water, which is then suddenly expelled by a strong muscular
effort.

[Illustration: 129. Agrion; _b_, False Gill of Larva.]

In the smaller forms, such as Agrion (A. saucium, Fig. 129; Fig. 129
_b_, side view of false gill, showing but one leaf), the respiratory
leaves, called the tracheary, or false-gills, are not enclosed within
the body, but form three broad leaves, permeated by tracheæ, or
air-vessels. They are not true gills, however, as the blood is not
aerated in them. They only absorb air to supply the tracheæ, which
aerate the blood only within the general cavity of the body. These false
gills also act as a rudder to aid the insect in swimming.

It is interesting to watch the Dragon flies through their
transformations, as they can easily be kept in aquaria. Little, almost
nothing, is known regarding their habits, and any one who can spend the
necessary time and patience in rearing them, so as to trace up the
different stages from the larva to the adult fly, and describe and
figure them accurately, will do good service to science.

[Illustration: 130. Pupa of Cordulia.]

Mr. Uhler states that at present we know but little of the young stages
of our species, but the larva and pupa of the Libellulas may be always
known from the Æschnas by the shorter, deeper and more robust form, and
generally by their thick clothing of hair. Figure 130 represents the
pupa of Cordulia lateralis, and figure 131 that of a Dragon fly referred
doubtfully to the genus Didymops. For descriptions and figures of other
forms the reader may turn to Mr. Louis Cabot's essay "On the Immature
State of the Odonata," published by the Museum of Comparative Zoology at
Cambridge.

[Illustration: 131. Pupa of Didymops?]

The pupa scarcely differs from the larva, except in having larger
wing-pads (Fig. 132). It is still active, and as much of a gourmand as
ever. When the insect is about to assume the pupa state, it moults its
skin. The body having outgrown the larva skin, by a strong muscular
effort a rent opens along the back of the thorax, and the insect having
fastened its claws into some object at the bottom of the pool, the pupa
gradually works its way out of the larva-skin. It is now considerably
larger than before. Immediately after this tedious operation, its body
is soft, but the crust soon hardens. This change, with most species,
probably occurs early in summer.

[Illustration: 132. Pupa of Æschna.]

When about to change into the adult fly, the pupa climbs up some plant
near the surface of the water. Again its back yawns wide open, and from
the rent our Dragon fly slowly emerges. For an hour or more, it remains
torpid and listless, with its flabby, soft wings remaining motionless.
The fluids leave the surface, the crust hardens and dries, rich and
varied tints appear, and our Dragon fly rises into its new world of
light and sunshine a gorgeous, but repulsive being. Tennyson thus
describes these changes in "The Two Voices":--

  To-day I saw the Dragon fly
  Come from the wells where he did lie.
  An inner impulse rent the veil
  Of his old husk: from head to tail
  Came out clear plates of sapphire mail.

  He dried his wings; like gauze they grew;
  Through crofts and pastures wet with dew
  A living flash of light he flew.

Of our more common, typical forms of Dragon flies, we figure a few,
commonly observed during the summer. The three-spotted Dragon fly
(Libellula trimaculata), of which figure 133 represents the male, is so
called from the three dark clouds on the wings of the female. But the
opposite sex differs in having a dark patch at the front edge of the
wings, and a single broad cloud just beyond the middle of the wing.

Libellula quadrimaculata, the four-spotted Dragon fly (Fig. 134), is
seen on the wing in June, flying through dry pine woods far from any
standing water.

[Illustration: 133. Libellula trimaculata, male.]

[Illustration: 134. Libellula quadrimaculata.]

The largest of our Dragon flies are the "Devil's Darning-needles,"
Eschna heros and grandis, seen hawking about our gardens till dusk. They
frequently enter houses, carrying dismay and terror among the children.
The hind-body is long and cylindrical, and gaily colored with bright
green and bluish bands and spots.

[Illustration: 135. Diplax Berenice, male.]

[Illustration: 136. Diplax Berenice, female.]

[Illustration: 137. Larva of Diplax.]

One of our most common Dragon flies is the ruby Dragon fly, Diplax
rubicundula, which is yellowish-red. It is seen everywhere flying over
pools, and also frequents dry sunny woods and glades. Another common
form is Diplax Berenice (Fig. 135 male, Fig. 136 female. The
accompanying cut (137) represents the larva, probably of this species,
according to Mr. Uhler.) It is black, the head blue in front, spotted
with yellow, while the thorax and abdomen are striped with yellow. There
are fewer stripes on the body of the male, which has only four large
yellow spots on each side of the abdomen. Still another pretty species
is Diplax Elisa (Fig. 138). It is black, with the head yellowish and
with greenish-yellow spots on the sides of the thorax and base of the
abdomen. There are three dusky spots on the front edge of each wing, and
a large cloud at the base of the hind pair towards the hind angles of
the wing.

Rather a rare form, and of much smaller stature is the Nannophya bella
(Fig. 138, female). It was first detected in Baltimore, and we
afterwards found it not unfrequently by a pond in Maine. Its abdomen is
unusually short, and the reticulations of the wings are large and
simple. The female is black, while the male is frosted over with a
whitish powder. Many more species of this family are found in this
country, and for descriptions of them we would refer the reader to Dr.
Hagen's "Synopsis of the Neuroptera of North America," published by the
Smithsonian Institution.

[Illustration: 138. Diplax Elisa.]

[Illustration: 139. Nannophya bella.]

[Illustration: 140. May Fly.]

The Libellulidæ, or family of Dragon flies, and the Ephemeridæ, or May
flies (Fig. 140), are the most characteristic of the Neuroptera, or
veiny-winged insects. This group is a most interesting one to the
systematist, as it is composed of so many heterogeneous forms which it
is almost impossible to classify in our rigid and at present necessarily
artificial systems. We divide them into families and sub-families,
genera and sub-genera, species and varieties, but there is an endless
shifting of characters in these groups. The different groups would seem
well limited after studying certain forms, when to the systematist's
sorrow, here comes a creature, perhaps mimicking an ant, or aphis, or
other sort of bug, or even a butterfly, and for which they would be
readily mistaken by the uninitiated. Bibliographers have gone mad over
books that could not be classified. Imagine the despair of an
insect-hunter and entomophile, as he sits down to his box of dried
neuroptera. He seeks for a true neuropter in the white ant before him,
but its very form and habits summon up a swarm of true ants; and then
the little wingless book louse (Atropos, Fig. 141) scampering
irreverently over the musty pages of his Systema Naturæ, reminds him of
that closest friend of man--Pediculus vestimenti. Again, his studies
lead him to that gorgeous inhabitant of the South, the butterfly-like
Ascalaphus, with its resplendent wings, and slender, knobbed antennæ so
much like those of butterflies, and visions of these beautiful insects
fill his mind's eye; or sundry dun-colored caddis flies, modest,
delicate neuroptera, with finely fringed wings and slender feelers,
create doubts as to whether they are not really allies of the clothes
moth, so close is the resemblance.

[Illustration: 141. Death Tick.]

Thus the student is constantly led astray by the wanton freaks Nature
plays, and becomes sceptical as regards the truth of a natural system,
though there is one to be discovered; and at last disgusted with the
stiff and arbitrary systems of our books,--a disgust we confess most
wholesome, if it only leads him into a closer communion with nature. The
sooner one leaves those maternal apron-strings,--books,--and learns to
identify himself with nature, and thus goes out of himself to affiliate
with the spirit of the scene or object before him,--or, in other words,
cultivates habits of the closest observation and most patient
reflection,--be he painter or poet, philosopher or insect-hunter of low
degree, he will gain an intellectual strength and power of interpreting
nature, that is the gift of true genius.

[Illustration: The Ant Lion and adult.]




CHAPTER XI.

MITES AND TICKS.


But few naturalists have busied themselves with the study of mites. The
honored names of Hermann, Von Heyden, Dugés, Dujardin and Pagenstecher,
Nicolet, Koch and Robin, and the lamented Claparède of Geneva, lead the
small number who have published papers in scientific journals. After
these, and except an occasional note by an amateur microscopist who
occasionally pauses from his "diatomaniacal" studies, and looks upon a
mite simply as a "microscopic object," to be classed in his micrographic
Vade Mecum with mounted specimens of sheep's wool, and the hairs of
other quadrupeds, a distorted proboscis of a fly, and podura scales, we
read but little of mites and their habits. But few readers of our
natural history text-books learn from their pages any definite facts
regarding the affinities of these humble creatures, their organization
and the singular metamorphosis a few have been known to pass through. We
shall only attempt in the present article to indicate a few of the
typical forms of mites, and sketch, with too slight a knowledge to speak
with much authority, an imperfect picture of their appearance and modes
of living.

Mites are lowly organized Arachnids. This order of insects is divided
into the Spiders, the Scorpions, the Harvestmen and the Mites (Acarina).
They have a rounded oval body, without the usual division between the
head-thorax and abdomen observable in spiders, the head-thorax and
abdomen being merged in a single mass. There are four pairs of legs, and
the mouth parts consist, as seen in the adjoining figure of a young tick
(Fig. 142, young Ixodes albipictus), of a pair of maxillæ (_c_), which
in the adult terminates in a two or three-jointed palpus, or feeler; a
pair of mandibles (_b_), often covered with several rows of fine teeth,
and ending in three or four larger hooks and a serrated labium (_a_).
These parts form a beak which the mite or tick insinuates into the flesh
of its host, upon the blood of which it subsists. While many of the
mites are parasitic on animals, some are known to devour the eggs of
insects and other mites, thrusting their beaks into the egg, and sucking
the contents. We have seen a mite (Nothrus ovivorus, Fig. 143) busily
engaged in destroying the eggs of a moth like that of the Canker worm,
and Dr. Shimer has observed the Acarus? malus sucking the eggs of the
Chinch bug. I have also observed another mite devouring the Aphides on
the rose leaves in my garden, so that a few mites may be set down as
beneficial to vegetation. While a few species are injurious to man, the
larger part are beneficial, being either parasitic and baneful to other
noxious animals, or more directly useful as scavengers, removing
decaying animal and vegetable substances.

[Illustration: 142, Ixodes albipictus and young.[8]]

The transformations of the mites are interesting to the philosophic
zoologist, since the young of certain forms are remarkably different
from the adults, and in reaching the perfect state the mite passes
through a metamorphosis more striking than that of many insects. The
young on leaving the egg have six legs, as we have seen in the case of
the Ixodes. Sometimes, however, as, for example, in the larva, as we may
call it, of a European mite, Typhlodromus pyri, the adult of which,
according to A. Scheuten, is allied to Acarus, and lives under the
epidermis of the leaves of the pear in Europe (while Mr. T. Taylor, of
the Department of Agriculture at Washington, has found a species in the
pear leaves about Washington, and still another form in peach leaves),
there are but two pairs of legs present, and the body is long,
cylindrical and in a degree worm-like.

I have had the good fortune to observe the different stages of a bird
mite, intermediate in its form between the Acarus and Sarcoptes, or Itch
mite. On March 6th, Mr. C. Cooke called my attention to certain little
mites which were situated on the narrow groove between the main stem of
the barb and the outer edge of the barbules of the feathers of the Downy
Woodpecker, and subsequently we found the other forms in the down under
the feathers. These long worm-like mites were evidently the young of a
singular Sarcoptes-like mite, as they were found on the same specimen of
Woodpecker at about the same date, and it is known that the growth of
mites is rapid, the metamorphoses, judging by the information which we
now possess, occupying usually but a few days.

[Illustration: 143. Egg-eating Mite.]

The young (though there is, probably, a still earlier hexapodous stage)
of this Sarcoptid has an elongated, oblong, flattened body, with four
short legs, provided with a few bristle-like hairs, and ending in a
stalked sucker, by aid of which the mite is enabled to walk over smooth,
hard surfaces. The body is square at the end, with a slight median
indentation, and four long bristles of equal length. They remained
motionless in the groove on the barb of the feather, and when removed
seemed very inert and sluggish. A succeeding stage of this mite, which
may be called the pupal, is considerably smaller than the larva and
looks somewhat like the adult, the body having become shorter and
broader. The adult is a most singular form, its body being rudely ovate,
with the head sunken between the fore legs, which are considerably
smaller than the second pair, while the third pair are twice as large as
the second pair, and directed backwards, and the fourth pair are very
small, not reaching the extremity of the body, which is deeply cleft and
supports four long bristles on each side of the cleft, while other
bristles are attached to the legs and body, giving the creature,
originally ill-shapen, a haggard, unkempt appearance. The two stigmata
or breathing pores open near the cleft in the end of the body, and the
external opening of the oviduct is situated between the largest and
third pair of legs. No males were observed. In a species of Acarus
(Tyroglyphus), somewhat like the Cheese mite, which we have alive at
the time of writing, in a box containing the remains of a Lucanus larva,
which they seem to have consumed, as both young and old are swarming
there by myriads, the young are oval and like the adults, except that
they are six-legged, the fourth pair growing out after a succeeding
moult.

Such is a brief summary of what has been generally known regarding the
metamorphoses of a few species of mites. In a few kinds no males have
been found; the females have been isolated after being hatched, and yet
have been known to lay eggs, which produced young without the
interposition of the males. This parthenogenesis has been noticed in
several species.

[Illustration: 144. Cheyletus.]

These insects often suddenly appear in vast numbers on various articles
of food and about houses, so as to be very annoying. Mr. J. J. H.
Gregory, of Marblehead, Mass., has found a mite allied to the European
species here figured (Fig. 144) very injurious to the seeds of the
cabbage, which it sucked dry. This is an interesting form, and we have
called it Cheyletus seminivorus It is of medium size, and especially
noticeable from the tripartite palpi, which are divided into an outer,
long, curved, claw-like lobe, with two rounded teeth at the base, and
two inner, slender lobes pectinated on the inner side, the third
innermost lobe being minute. The beak terminates in a sharp blade-like
point.

We have received a Cheyletus-like mite, said to have been "extracted
from the human face" in New Orleans. The body is oblong, square behind;
the head is long and pointed, while the maxillæ end in a long, curved,
toothed, sickle-like blade. That this creature has the habits of the
itch mite is suggested by the curious, large, hair-like spines with
which the body and legs are sparsely armed, some being nearly half as
long as the body. These hairs are covered with very fine spinules. Those
on the end of the body are regularly spoon-shaped. These strange hairs,
which are thickest on the legs, probably assisted the mite in anchoring
itself in the skin of its host. We have read no account of this strange
and interesting form. It is allied to the Acaropsis Mericourti which
lives in the human face.

A species, "apparently of the genus Gamasus," according to Dr. Leidy,
has been found living in the ear (at the bottom of the external auditory
meatus, and attached to the membrana tympani) of steers. "Whether this
mite is a true parasite of the ear of the living ox, or whether it
obtained access to the position in which it was found after the death of
the ox in the slaughter house, has not yet been determined."

We will now give a hasty glance at the different groups of mites,
pausing to note those most interesting from their habits or relation to
man.

The most highly organized mite (and by its structure most closely allied
to the spider) is the little red garden mite, belonging to the genus
Trombidium, to which the genus Tetranychus is also nearly related. Our
own species of the former genus have not been "worked up," or in other
words identified and described, so that whether the European T.
holosericeum Linn. is our species or not, we cannot tell. The larvæ of
this and similar species are known to live parasitically upon Harvestmen
(Phalangium), often called Daddy-long-legs; and upon Aphides,
grasshoppers and other insects. Mr. Riley has made known to us through
the "American Naturalist" (and from his account our information is
taken), the habits of certain young of the garden mite (Trombidium)
which are excessively annoying in the Southwestern States. The first is
the Leptus? Americanus (Fig. 145), or American Harvest mite. It is only
known as yet in the larval or Leptus state, when it is of the form
indicated in the cut, and brick red in color. "This species is barely
visible with the naked eye, moves readily and is found more frequently
upon children than upon adults. It lives mostly on the scalp and under
the arm pits, but is frequently found on the other parts of the body. It
does not bury itself in the flesh, but simply insinuates the anterior
part of the body just under the skin, thereby causing intense
irritation, followed by a little red pimple. As with our common ticks,
the irritation lasts only while the animal is securing itself, and its
presence would afterwards scarcely be noticed but for the pimple which
results."

[Illustration: 145 _a._ American Harvest Mite; _b._ Irritating Harvest
Mite; the dots underneath indicating the natural size.]

The second species (Fig. 145 _b_, Leptus? irritans) is also only known
in the Leptus stage. It is evidently the larva of a distinct genus from
the other form, having enormous maxillæ and a broad body; it is also
brick red. Mr. Riley says that "this is the most troublesome and,
perhaps, best known of the two, causing intense irritation and swelling
on all parts of the body, but more especially on the legs and around the
ankles. Woe betide the person who, after bathing in the Mississippi
anywhere in this latitude, is lured to some green dressing-spot of weeds
or grass! He may, for the time, consider himself fortunate in getting
rid of mud and dirt, but he will afterwards find to his sorrow that he
exchanged them for something far more tenacious in these microscopic
Harvest-mites. If he has obtained a good supply of them, he will in a
few hours begin to suffer from severe itching, and for the next two or
three days will be likely to scratch until his limbs are sore.

"With the strong mandibles and the elbowed maxillæ which act like arms,
this mite is able to bury itself completely in the flesh, thereby
causing a red swelling with a pale pustulous centre containing watery
matter. If, in scratching, he is fortunate enough to remove the mite
before it enters, the part soon heals. But otherwise the irritation
lasts for two, three or four days, the pustulous centre reappearing as
often as it is broken.

"The animal itself, on account of its minute size, is seldom seen, and
the uninitiated, when first troubled with it, are often alarmed at the
symptoms and at a loss to account for them. Fortunately these little
plagues never attach themselves to persons in such immense numbers as do
sometimes young or so-called 'seed' ticks; but I have known cases where,
from the irritation and consequent scratching, the flesh had the
appearance of being covered with ulcers; and in some localities, where
these pests most abound, sulphur is often sprinkled during 'jigger'
season in the boots or shoes as a protection.

"Sulphur ointment is the best remedy against the effects of either of
these mites, though when that cannot be obtained, saleratus water and
salt water will partially allay the irritation.

"The normal food of either must, apparently, consist of the juices of
plants, and the love of blood proves ruinous to those individuals who
get a chance to indulge it. For unlike the true Jigger, the female of
which deposits eggs in the wound she makes, these Harvest-mites have no
object of the kind, and when not killed by the hands of those they
torment, they soon die victims to their sanguinary appetite."

[Illustration: 146. Astoma of the Fly.]

Another Leptus-like form is the parasite of the fly, described by Mr.
Riley under the name of Astoma? muscarum (Fig. 146). How nearly allied
it is to the European Astoma parasiticum we have not the means of
judging.

The European Tetranychus telarius Linn., or web-making mite, spins large
webs on the leaves of the linden tree. Then succeed in the natural order
the water mites (Hydrachna), which may be seen running over submerged
sticks and on plants, mostly in fresh water, and rarely on the borders
of the sea. The young after leaving the egg differ remarkably from the
adults, so as to have been referred to a distinct genus (Achlysia) by
the great French naturalist, Audouin. They live as parasites on various
water insects, such as Dytiscus, Nepa and Hydrometra, and when mature
live free in the water, though Von Baer observed an adult Hydrachna
concharum living parasitically on the gills of the fresh-water mussel,
Anodon. The species are of minute size. Collectors of beetles often meet
with a species of Uropoda attached firmly to their specimens of
dung-inhabiting or carrion beetles. It is a smoothly polished, round,
flattened mite, with short, thick legs, scarcely reaching beyond the
body.

[Illustration: 147. Cattle Tick.]

We now come to the Ticks, which comprise the largest mites. The genus
Argas closely resembles Ixodes. Gerstaecker states that the Argas
Persicus is very annoying to travellers in Persia. The habits of the
wood ticks (Ixodes) are well known. Travellers in the tropics speak of
the intolerable torment occasioned by these pests which, occurring
ordinarily on shrubs and trees, attach themselves to all sorts of
reptiles, beasts and cattle, and even man himself as he passes by within
their reach. Sometimes cases fall within the practice of the physician,
who is called to remove the tick, which is found sometimes literally
buried beneath the skin. Mr. J. Stauffer writes me, that "on June 23d
the daughter of Abraham Jackson (colored), playing among the leaves in a
wood, near Springville, Lancaster County, Penn., on her return home
complained of pain in the arm. No attention was paid to it till the next
day, when a raised tumor was noticed, a small portion protruding through
the skin, apparently like a splinter of wood. The child was taken to Dr.
Morency, who applied the forceps, and after considerable pain to the
child, and labor to himself, extracted a species of Ixodes, nearly
one-quarter of an inch long, and of an oval form and brown mahogany
color, with a metallic spot, like silver bronze, centrally on the dorsal
region." This tick proved, from Mr. Stauffer's figures, to be, without
doubt, Ixodes unipunctata. It has also been found in Massachusetts by
Mr. F. G. Sanborn.

Another species is the Ixodes bovis (Fig. 147), the common cattle tick
of the Western States and Central America. It is very annoying to horned
cattle, gorging itself with their blood, but is by no means confined to
them alone, as it lives indifferently upon the rattlesnake, the iguana,
small mammals and undoubtedly any other animal that brushes by its
lurking-place in the forest. It is a reddish, coriaceous, flattened,
seed-like creature, with the body oblong oval, and contracted just
behind the middle. When fully grown it measures from a quarter to half
an inch in length. We have received it from Missouri, at the hands of
Mr. Riley, and Mr. J. A. McNiel has found it very abundantly on horned
cattle on the western coast of Nicaragua.

We now come to the genus Acarus (Tyroglyphus), of which the cheese and
sugar mites are examples. Some species of Acarian mites have been found
in the lungs and blood-vessels, and even the intestinal canal of certain
vertebrates, while the too familiar itch insect lurks under the skin of
the hand and other parts of the body of certain uncleanly human bipeds.

[Illustration: 148. Sugar Mite.]

Many people have been startled by statements in newspapers and more
authoritative sources, as to the immense numbers of mites (Acarus
sacchari, Fig. 148) found in unrefined or raw sugar. According to Prof.
Cameron, of Dublin, as quoted in the "Journal of the Franklin
Institute," for November, 1868, "Dr. Hassel (who was the first to notice
their general occurrence in the raw sugar sold at London) found them in
a living state in no fewer than sixty-nine out of seventy-two samples.
He did not detect them in a single specimen of refined sugar. In an
inferior sample of raw sugar, examined in Dublin by Mr. Cameron, he
reports finding five hundred mites in ten grains of sugar, so that in a
pound's weight occurred one hundred thousand of these little creatures,
which seem to have devoted themselves with a martyr-like zeal to the
adulteration of sugar. They appear as white specks in the sugar. The
disease known as grocer's itch is, undoubtedly, due to the presence of
this mite, which, like its ally the Sarcoptes, works its way under the
skin of the hand, in this case, however, of cleanly persons. Mr. Cameron
states that "the kind of sugar which is both healthful and economical,
is the dry, large-grained and light-colored variety."

Closely allied to the preceding, is the Cheese mite (Acarus siro Linn.),
which often abounds in newly made cheese. Lyonet states that during
summer this mite is viviparous. Acarus farinæ DeGeer, as its name
indicates, is found in flour. Other species have been known to occur in
ulcers.

[Illustration: 149. Mange Mite.]

We should also mention the Mange insect of the horse (Psoroptes equi,
Fig. 149, much enlarged; _a_, head more magnified). According to Prof.
Verrill it is readily visible to the naked eye and swarms on horses
afflicted with the mange, which is a disease analogous to the itch in
man. It has a soft, depressed body, spiny beneath at the base of the
legs and on the thorax. One or both of the two posterior pairs of feet
bear suckers, and all are more or less covered with long, slender hairs.
This insect may be destroyed by the same remedies as are used for lice
and for the human itch. The best remedy is probably a solution of
sulphuret of potassium.

[Illustration: 150. Itch Mite.]

[Illustration: 151. Nose Mite.]

The itch insect (Sarcoptes scabiei, Fig. 150) was first recognized by an
Arabian author of the twelfth century, as the cause of the disease which
results from its attacks. The body of the insect is rounded, with the
two hind pair of feet rudimentary and bearing long hairs. It buries
itself in the skin on the more protected parts of the body, and by its
punctures maintains a constant irritation. Other species are known to
infest the sheep and dog. Another singular mite is the Demodex
folliculorum (Fig. 151), which was discovered by Dr. Simon, of Berlin,
buried in the diseased follicles of the wings of the nose in man. It is
a long, slender, worm-like form, with eight short legs, and in the
larva state has six legs. This singular form is one of the lowest and
most degraded of the order of Arachnids. A most singular mite was
discovered by Newport on the body of a larva of a wild bee, and
described by him under the name of Heteropus ventricosus. The body of
the fully formed female is long and slender. After attaining this form,
its small abdomen begins to enlarge until it assumes a globular form,
and the mass of mites look like little beads. Mr. Newport was unable to
discover the male, and thought that this mite was parthenogenous. It
will be seen that the adult Demodex retains the elongated, worm-like
appearance of the larva of the higher mites, such as Typhlodromus. This
is an indication of its low rank, and hints of a relationship to the
Tardigrades and the Pentastoma, the latter being a degraded mite, and
the lowest of its order, living parasitically within the bodies of other
animals.

[Illustration: Harvestman.]

FOOTNOTES:

[Footnote 8: The figure at the bottom on the left represents the adult,
fully-gorged tick.]




CHAPTER XII.

BRISTLE-TAILS AND SPRING-TAILS.


The Thysanura, as the Poduras and their allies, the Lepismas, are
called, have been generally neglected by entomologists, and but few
naturalists have paid special attention to them.[9] Of all those
microscopists who have examined Podura scales as test objects, we wonder
how many really know what a Podura is?

In preparing the following account I have been under constant
indebtedness to the admirable and exhaustive papers of Sir John Lubbock,
in the London "Linnæan Transactions" (vols. 23, 26 and 27).
Entomologists will be glad to learn that he is shortly going to press
with a volume on the Poduras, which, in distinction from the Lepismas,
to which he restricts the term Thysanura, he calls Collembola, in
allusion to the sucker-like tubercle situated on the under side of the
body, which no other insects are known to possess.

The group of Bristle-tails, as we would dub the Lepismas in distinction
from the Spring-tails, we will first consider. They are abundant in the
Middle States under stones and leaves in forests, and northward are
common in damp houses, while one beautiful species that we have never
noticed elsewhere, is our "cricket on the hearth," abounding in the
chinks and crannies of the range of our house, and also in closets,
where it feeds on sugar, etc., and comes out like cockroaches, at night,
shunning the light. Like the cockroaches, which it vaguely resembles in
form, this species loves hot and dry localities, in distinction from the
others which seek moisture as well as darkness. By some they are called
"silver witches," and as they dart off, when disturbed, like a streak of
light, their bodies being coated in a suit of shining mail, which the
arrangement of the scales resembles, they have really a weird and
ghostly look.

The most complicated genus, and the one which stands at the head of the
family, is Machilis, one species of which lives in the Northern and
Middle States, and another in Oregon. They affect damp places, living
under leaves and stones. They all have rounded, highly arched bodies,
and large compound eyes, the two being united together. The maxillary
palpi are greatly developed, but the chief characteristics are the
two-jointed stylets arranged in nine pairs along each side of the
abdomen, reminding us of the abdominal legs of Myriopods. The body ends
in three long bristles, as in Lepisma.

The Lepisma saccharina of Linnæus, if, as is probable, that is the name
of our common species, is not uncommon in old damp houses, where it has
the habits of the cockroach, eating cloths, tapestry, silken trimmings
of furniture, and doing occasional damage to libraries by devouring the
paste, and eating holes in the leaves and covers of books.

In general form Lepisma may be compared to the larva of Perla, a
net-veined Neuropterous insect, and also to the narrow-bodied species of
cockroaches, minus the wings. The body is long and narrow, covered with
rather coarse scales, and ends in three many jointed anal stylets, or
bristles, which closely resemble the many jointed antennæ, which are
remarkably long and slender. The thermophilous species already alluded
to may be described as perhaps the type of the genus, the L. saccharina
being simpler in its structure. The body is narrow and flattened; the
basal joints of the legs being broad, flat and almost triangular, like
the same joints in the cockroaches. The legs consist of six joints, the
tarsal joints being large and two in number, and bearing a pair of
terminal curved claws. The three thoracic segments are of nearly equal
size, and the eight abdominal segments are also of similar size. The
tracheæ are well developed, and may be readily seen in the legs. The end
of the rather long and weak abdomen is propped up by two or three pairs
of bristles, which are simple, not jointed, but moving freely at their
insertion; thus they take the place of legs, and remind one of the
abdominal legs of the Myriopods; and we shall see in certain other
genera (Machilis and Campodea) of the Bristle-tails that there are
actually two-jointed bristles arranged in pairs along the abdomen. They
may probably be directly compared with the abdominal legs of Myriopods.
Further study, however, of the homologies of these peculiar appendages,
and especially a knowledge of the embryological development of Lepisma
and Machilis, is needed before this interesting point can be definitely
settled. The three many jointed anal stylets may, however, be directly
compared with the similar appendages of Perla and Ephemera. The mode of
insertion of the antennæ of this family is much like that of the
Myriopods, the front of the head being flattened, and concealing the
base of the antennæ, as in the Centipedes and Pauropus. Indeed, the head
of any Thysanurous insect seen from above, bears a general resemblance
in some of its features to that of the Centipede and its allies. So in a
less degree does the head of the larvæ of certain Neuroptera and
Coleoptera. The eyes are compound, the single facets forming a sort of
heap. The clypeus and labrum, or upper lip, is, in all the Thysanura,
carried far down on the under side of the head, the clypeus being almost
obsolete in the Poduridæ, this being one of the most essential
characters of that family. Indeed, it is somewhat singular that these
and other important characteristics of this group have been almost
entirely passed over by authors, who have consequently separated these
insects from other groups on what appear to the writer as comparatively
slight and inconsiderable characters. The mouth-parts of the Lepismatidæ
(especially the thermophilous Lepisma, which we now describe) are most
readily compared with those of the larva of Perla. The rather large,
stout mandibles are concealed at their tips, under the upper lip, which
moves freely up and down when the creature opens its mouth. The mandible
is about one-third as broad as long, armed with three sharp teeth on the
outer edge, and with a broad cutting edge within, and still further
inwards a lot of straggling spinules. In all these particulars, the
mandible of Lepisma is comparable with that of certain Coleoptera and
Neuroptera. So also are the maxillæ and labium, though we are not aware
that any one has indicated how close the homology is. The accompanying
figure (152) of the maxilla of a beetle may serve as an example of the
maxilla of the Coleoptera, Orthoptera and Neuroptera. In these insects
it consists almost invariably of three lobes, the outer being the
palpus, the middle lobe the galea, and the innermost the lacinia; the
latter undergoing the greatest modifications, forming a comb composed of
spines and hairs varying greatly in relative size and length. How much
the palpi vary in these groups of insects is well known. The galea
sometimes forms a palpus-like appendage. Now these three lobes may be
easily distinguished in the maxilla of Lepisma. The palpus instead of
being directed forward, as in the insects mentioned above (in the pupa
of Ephemera the maxilla is much like that of Lepisma), is inserted
nearer the base than usual and thrown off at right angles to the
maxilla, so that it is stretched out like a leg, and in moving about the
insect uses its maxillæ partly as supports for its head. They are very
long and large, and five or six-jointed. The galea, or middle division,
forms a simple lobe, while the lacinia has two large chitinous teeth on
the inner edge, and internally four or five hairs arising from a thin
edge.

[Illustration: 152. Maxilla.]

The labium is much as in that of Perla, being broad and short, with a
distinct median suture, indicating its former separation in embryonic
life into a pair of appendages. The labial palpi are three-jointed, the
joints being broad, and in life directed backwards instead of forwards
as in the higher insects.

There are five American species of the genus Lepisma in the Museum of
the Peabody Academy. Besides the common L. saccharina? there are four
undescribed species; one found about out-houses and cellars, and the
heat-loving form, perhaps an imported, species, found in a kitchen in
Salem, and apparently allied to the L. thermophila Lucas, of houses in
Brest, France; and lastly two allied forms, one from Key West, and
another from Polvon, Western Nicaragua, collected by Mr. McNiel. The
last three species are beautifully ornamented with finely spinulated
hairs arranged in tufts on the head; while the sides of the body, and
edges of the basal joints of the legs are fringed with them.

The interesting genus Nicoletia stands at the bottom of the group. It
has the long, linear, scaleless body of Campodea, in the family below,
but the head and its appendages are like Lepisma, the maxillary palpi
being five-jointed, and the labial palpi four-jointed. The eyes are
simple, arranged in a row of seven on each side of the head. The abdomen
ends in three long and many jointed stylets, and there are the usual
"false branchial feet" along each side of the abdomen. There are two
European species which occur in greenhouses. No species have yet been
found in America.

[Illustration: 153. Japyx solifugus.]

The next family of Thysanura is the Campodeæ, comprising the two genera
Campodea and Japyx. These insects are much smaller than the Lepismidæ,
and in some respects are intermediate between that family and the
Poduridæ (including the Smynthuridæ).

In this family the body is long and slender, and the segments much alike
in size. There is a pair of spiracles on each thoracic ring. The
mandibles are long and slender, ending in three or four teeth, and with
the other appendages of the mouth are concealed within the head, "only
the tips of the palpi (and of the maxillæ when these are opened)
projecting a very little beyond the rounded entire margin of the
epistoma," according to Haliday. The maxillæ are comb-shaped, due to the
four slender, minutely ciliated spines placed within the outer tooth.
The labium in Japyx is four-lobed and bears a small two-jointed palpus.
The legs are five-jointed, the tarsi consisting of a single joint,
ending in two large claws. The abdomen consists of ten segments, and in
Campodea along each side is a series of minute, two-jointed appendages
such as have been described in Machilis. These are wanting in Japyx.
None of the species in this family have the body covered with scales.
They are white, with a yellowish tinge.


The more complicated genus of the two is Japyx (Fig. 153, Japyx
solifugus, found under stones in Southern Europe; _a_, the mouth from
beneath, with the maxillæ open; _b_, maxilla; _d_, mandible; _c_,
outline of front of head seen from beneath, with the labial palpi in
position) which, as remarked by the late Mr. Haliday (who has published
an elaborate essay on this genus in the Linnæan Transactions, vol. 24,
1864), resembles Forficula in the large forceps attached to its tail. An
American species (J. Saussurii) lives in Mexico, and we look for its
discovery in Texas.

[Illustration: 154. Campodea staphylinus.]

Campodea (C. staphylinus Westw., Fig. 154, enlarged; _a_, mandible; _b_,
maxilla), otherwise closely related, has more rudimentary mouth-parts,
and the abdomen ends in two many jointed appendages.

[Illustration: Fig. 155. Larva of Perla.]

Our common American species of Campodea (C. Americana) lives under
stones in damp places. It is yellowish, about a sixth of an inch in
length, is very agile in its movements, and would easily be mistaken for
a very young Lithobius. A larger species and differing in having longer
antennæ, has been found by Mr. C. Cooke in Mammoth Cave, and has been
described in the "American Naturalist" under the name of Campodea
Cookei. Haliday has remarked that this family bears much resemblance to
the Neuropterous larva of Perla (Fig. 155), as previously remarked by
Gervais; and the many points of resemblance of this family and the
Lepismidæ to the larval forms of some Neuroptera that are active in the
pupa state (the Pseudoneuroptera of Erichson and other authors) are very
striking. Campodea resembles the earliest larval form of Chloëon, as
figured by Sir John Lubbock, even to the single jointed tarsus; and why
these two Thysanurous families should be removed from the Neuroptera we
are unable, at present, to understand, as to our mind they scarcely
diverge from the Neuropterous type more than the Mallophaga, or biting
lice, from the type of Hemiptera.

Haliday, remarking on the opinion of Linnæus and Schrank, who referred
Campodea to the old genus Podura, says with much truth, "it may be
perhaps no unfair inference to draw, that the insect in question is in
some measure intermediate between both," _i. e._, Podura and Lepisma.
This is seen especially in the mouth-parts which are withdrawn into the
head, and become very rudimentary, affording a gradual passage into the
mouth-parts of the Poduridæ, which we now describe.

The next group, the Podurelles of Nicolet, and Collembola of Lubbock,
are considered by the latter, who has studied them with far more care
than any one else, as "less closely allied" to the Lepismidæ "than has
hitherto been supposed." He says "the presence of tracheæ, the structure
of the mouth and the abdominal appendage; all indicate a wide
distinction between the Lepismidæ and the Poduridæ. We must, indeed, in
my opinion, separate them entirely from one another; and I would
venture to propose for the group comprised in the old genus Podura, the
term Collembola, as indicating the existence of a projection, or
mammilla, enabling the creature to attach or glue itself to the body on
which it stands." Then without expressing his views as to the position
and affinities of the Lepismidæ, he remarks "as the upshot of all this,
then, while the Collembola are clearly more nearly allied to the Insecta
than to the Crustacea or Arachnida, we cannot, I think, regard them as
Orthoptera or Neuroptera, or even as true insects. That is to say, the
Coleoptera, Orthoptera, Neuroptera, Lepidoptera, etc., are in my
opinion, more nearly allied to one another than they are to the Poduridæ
or Smynthuridæ. On the other hand, we certainly cannot regard the
Collembola as a group equivalent in value to the Insecta. If, then, we
attempt to map out the Articulata, we must, I think, regard the
Crustacea and Insecta as continents, the Myriopoda and Collembola as
islands--of less importance, but still detached. Or, if we represent the
divisions of the Articulata like the branching of a tree, we must
picture the Collembola as a separate branch, though a small one, and
much more closely connected with the Insecta than with the Crustacea or
the Arachnida." Lamarck regarded them as more nearly allied to the
Crustacea than Insecta. Gervais, also, in the "Histoire Naturelle des
Insectes: Aptères," indicates a considerable diversity existing between
the Lepismidæ and Poduridæ, though they are placed next to each other.
Somewhat similar views have been expressed by so high an authority as
Professor Dana, who, in the "American Journal of Science" (vol. 37,
Jan., 1864), proposed a classification of insects based on the principle
of cephalization, and divided the Hexapodous insects into three groups:
the first (Ptero-prosthenics, or Ctenopters) comprising the Hymenoptera,
Diptera, Aphaniptera (fleas), Lepidoptera, Homoptera, Trichoptera and
Neuroptera; the second group (Ptero-metasthenics, or Elytropters)
comprising the Coleoptera, Hemiptera and Orthoptera; while the Thysanura
compose the third group. Lubbock has given us a convenient historical
view of the opinions of different authors regarding the classification
of these insects, which we find useful. Nicolet, the naturalist who,
previous to Lubbock, has given us the most correct and complete account
of the Thysanura, regarded them as an order, equivalent to the
Coleoptera or Diptera, for example. In this he followed Latreille, who
established the order in 1796. The Abbé Bourlet adopted the same view.
On the other hand Burmeister placed the Thysanura as a separate tribe
between the Mallophaga (Bird Lice) and Orthoptera, and Gerstaecker
placed them among the Orthoptera. Fabricius and Blainville put them with
the Neuroptera, and the writer, in his "Guide to the Study of Insects,"
and previously in 1863, ignorant of the views of the two last named
authors, considered the Thysanura as degraded Neuroptera, and noticed
their resemblance to the larvæ of Perla, Ephemera, and other Neuroptera,
such as Rhaphidia and Panorpa, regarding them as standing "in the same
relation to the rest of the Neuroptera [in the Linnæan sense], as the
flea does to the rest of the Diptera, or the lice and Thrips to the
higher Hemiptera."

After having studied the Thysanura enough to recognize the great
difficulty of deciding as to their affinities and rank, the writer does
not feel prepared to go so far as Dana and Lubbock, for reasons that
will be suggested in the following brief account of the more general
points in their structure, reserving for another occasion a final
expression of his views as to their classification.

The Poduridæ, so well known by name, as affording the scales used by
microscopists as test objects, are common under stones and wet chips, or
in damp places, cellars, mushrooms and about manure heaps. They need
moisture, and consequently shade. They abound most in spring and autumn,
laying their eggs at both seasons, though most commonly in the spring.
During a mild December, they may be found in abundance under sticks and
stones, even in situations so far north as Salem, Mass.

[Illustration: 156. Smynthurus.]

The body of the Poduras is rather short and thick, most so in Smynthurus
(Fig. 156), and becoming long and slender in Tomocerus and Isotoma. The
segments are inclined to be of unequal size, the prothoracic ring
sometimes becoming almost obsolete, and some of the abdominal rings are
much smaller than others; while in Lipura and Anura, the lowest forms of
the group, the segments are all much alike in size.

The head is in form much like that of certain larvæ of Neuroptera and of
Forficula, an Orthopterous insect. The basal half of the head is marked
off from the eye-bearing piece (epicranium) by a V-shaped suture[10]
(Fig. 157, head of Degeeria; compare also the head of the larva of
Forficula, Fig. 158, in which the suture is the same), and the insertion
of the antennæ is removed far down the front, near the mouth, the
clypeus being very short; this piece, so large and prominent in the
higher insects, is not distinctly separated by suture from the
surrounding parts of the head, thus affording one of the best
distinctive characters of the Poduridæ. The eyes are situated on top of
the head just behind the antennæ, and are simple, consisting of a group
of from five to eight or ten united into a mass in Smynthurus, but
separated in the Poduridæ (see Fig. 176, _e_, eye of Anurida). The
antennæ are usually four-jointed, and vary in length in the different
genera.

[Illustration: 157. Head of Degeeria.]

[Illustration: 158. Larva of Forficula.]

The mouth-parts are very difficult to make out, but by soaking the
insect in potash for twenty-four hours, thus rendering the body
transparent, they can be satisfactorily observed. They are constructed
on the same general type as the mouth-parts of the Neuroptera,
Orthoptera and Coleoptera, and except in being degraded, and with
certain parts obsolete, they do not essentially differ.[11] On observing
the living Podura, the mouth seems a simple ring, with a minute labrum
and groups of hairs and spinules, which the observer, partly by
guess-work, can identify as jaws and maxillæ, and labium. But in
studying the parts rendered transparent, we can identify the different
appendages. Figure 159 shows the common Tomocerus plumbeus greatly
enlarged (Fig. 160, seen from above), and as the mouth-parts of the
whole group of Poduras are remarkably constant, a description of one
genus will suffice for all. The labrum, or upper lip, is separated by a
deep suture from the clypeus, and is trapezoidal in form. The mandibles
and maxillæ are long and slender, and buried in the head, with the tips
capable of being extended out from the ring surrounding the mouth for a
very short distance. The mandibles (_md_, Fig. 159) are like those of
the Neuroptera, Orthoptera and Coleoptera in their general form, the tip
ending in from three to six teeth (three on one mandible and six on the
other), while below, is a rough, denticulated molar surface, where the
food seized by the terminal teeth is triturated and prepared to be
swallowed. Just behind the mandibles are the maxillæ, which are
trilobate at the end, as in the three orders of insects above named. The
outer lobe, or palpus, is a minute membranous tubercle ending in a hair
(Fig. 161, _mp_), while the middle lobe, or galea, is nearly obsolete,
though I think I have seen it in Smynthurus, where it forms a lobe on
the outside of the lacinia. The lacinia, or inner lobe (Fig. 161, _lc_;
162, the same enlarged), in Tomocerus consists of two bundles of
spinules, one broad like a ruffle, and the other slender, pencil-like,
ending in an inner row of spines, like the spinules on the lacinia of
the Japyx and Campodea and, more remotely, the laciniæ of the three
sub-orders of insects above referred to. There is also a horny,
prominent, three-toothed portion (Fig. 161, _g_). These homologies have
never been made before, so far as the writer is aware, but they seem
natural, and suggested by a careful examination and comparison with the
above-mentioned mandibulate insects.

[Illustration: 159. 161. 160. 162.

Tomocerus plumbeus and mouth-parts, greatly enlarged.]

The spring consists of a pair of three-jointed appendages, with the
basal joints soldered together early in embryonic life, while the other
two joints are free, forming a fork. It is longest in Smynthurus and
Degeeria, and shortest in Achorutes (Fig. 172, _b_), where it forms a
simple, forked tubercle; and is obsolete in Lipura and Anura, its place
being indicated by an oval scar. The third joint varies in form, being
hairy, serrate and knife-like in form, as in Tomocerus (Fig. 159, _a_),
or minute, with a supplementary tooth, as in Achorutes (Fig. 172,
_c_). This spring is in part homologous with the ovipositor of the
higher insects, which originally consists of three pairs of tubercles,
each pair arising apparently from the seventh, eighth, and ninth (the
latter the penultimate) segments of the abdomen in the Hymenoptera. The
spring of the Podura seems to be the homologue of the third pair of
these tubercles, and is inserted on the penultimate segment. This
comparison I have been able to make from a study of the embryology of
Isotoma.

[Illustration: 163. Catch holding spring of Achorutes.]

Another organ, and one which, so far as I am aware, has been overlooked
by previous observers, I am disposed to consider as possibly an
ovipositor. In the genus Achorutes, it may be found in the segment just
before the spring-bearing segment, and situated on the median line of
the body. It consists (Fig. 163) of two squarish valves, from between
which projects a pair of minute tubercles, or blades, with four rounded
teeth on the under side. This pair of infinitesimal saws reminds one of
the blades of the saw-fly, and I am at a loss what their use can be
unless to cut and pierce so as to scoop out a shallow place in which to
deposit an egg. It is homologous in situation with the middle pair of
blades which composes the ovipositor of higher insects, and if it should
prove to be used by the creature in laying its eggs, we should then
have, with the spring, an additional point of resemblance to the
Neuroptera and higher insects, and instead of this spring being an
important differential character, separating the Thysanura from other
insects, it binds them still closer, though still differing greatly in
representing only a part of the ovipositor of the higher insects. (This
is a catch for holding the spring in place.)

But all the Poduras differ from other insects in possessing a remarkable
organ situated on the basal segment of the abdomen. It is a small
tubercle, with chitinous walls, forming two valves from between which is
forced out a fleshy sucker, or, as in Smynthurus, a pair of long tubes,
which are capable of being darted out on each side of the body, enabling
the insect to attach itself to smooth surfaces, and rest in an inverted
position.

The eggs are laid few in number, either singly or several together, on
the under side of stones, chips or, as in the case of Isotoma Walkerii,
under the bark of trees. They are round, transparent. The development of
the embryo of Isotoma in general accords with that of the Phryganeidæ
and suggests on embryological grounds the near relationship of the
Thysanura to the Neuroptera.

[Illustration: 164. 165. 166. 167.

Development of a Poduran.]

The earliest stage observed was at the time of the appearance of the
primitive band (Fig. 164, _a_, _b_, folding of the primitive band; _c_,
the dotted line crosses the primitive band, and terminates in a large
yolk granule) which surrounds the egg as in the Caddis flies. Soon
after, the primitive segments appear (Fig. 165; 1, antennæ; 2,
mandibles; 3, maxillæ; the labium was not seen; 5-7, legs; _c_, yolk
surrounded by the primitive band) and seem to originate just as in the
Caddis flies. Figure 166 is a front view of the embryo shortly before
it is hatched; figure 167, side view of the same, the figures as in Fig.
165; _sp_, spring; _l_, labrum. The labrum or upper lip, and the clypeus
are large and as distinct as in the embryos of other insects, a fact to
which we shall allude again. The large three-jointed spring is now well
developed, and the inference is drawn that it represents a pair of true
abdominal legs. The embryo when about to hatch throws off the egg-shell
and amnion in a few seconds. The larva is perfectly white and is very
active in its movements, running over the damp, inner surface of the
bark. It is a little over a hundredth of an inch in length, and differs
from the adult in being shorter and thicker, with the spring very short
and stout. In fact the larva assumes the form of the lower genera of the
family, such as Achorutes and Lipura, the adult more closely resembling
Degeeria. The larva after its first moult retains its early clumsy form,
and is still white. After a second moult it becomes purplish, and much
more slender, as in the adult. The eggs are laid and the young hatched
apparently within a period of from six to ten days.

Returning to the stage indicated by figures 166 and 167, I am induced to
quote some remarks published in the Memoirs of the Peabody Academy of
Science, No. 2, p. 18, which seem to support the view that these insects
are offshoots from the Neuroptera.

"The front of the head is so entirely different from what it is in the
adult, that certain points demand our attention. It is evident that at
this period the development of the insect has gone on in all important
particulars much as in other insects, especially the Neuropterous
Mystacides as described by Zaddach. The head is longer vertically than
horizontally, the frontal, or clypeal region is broad, and greater in
extent than the epicranio-occipital region. The antennæ are inserted
high up on the head, next the ocelli, falling down over the clypeal
region. The clypeus, however, is merged with the epicranium, and the
usual suture between them does not appear distinctly in after life,
though its place is seen in figure 167 to be indicated by a slight
indentation. The labrum is distinctly defined by a well marked suture,
and forms a squarish, knob-like protuberance, and in size is quite large
compared to the clypeus. From this time begins the process of
degradation, when the insect assumes its Thysanurous characters, which
consist in an approach to the form of the Myriopodous head, the front,
or clypeal region being reduced to a minimum, and the antennæ and eyes
brought in closer proximity to the mouth than in any other insects."

Sir John Lubbock has given us an admirable account of the internal
anatomy of these little creatures, his elaborate and patient dissections
filling a great gap in our knowledge of their internal structure. The
space at our disposal only permits us to speak briefly of the
respiratory system. Lubbock found a simple system of tracheæ in
Smynthurus which opens by "two spiracles in the head, opposite the
insertion of the antennæ," _i. e._, on the back of the head. (Von Olfers
says that they open on the prothorax.) Nicolet and Olfers claim to have
found tracheæ in several lower genera (Orchesella, Tomocerus, and
Achorutes and allied genera), but Lubbock was unable to detect them, and
I may add that I have not yet been able after careful search to find
them either in living specimens, or those rendered transparent by
potash.

Having given a hasty sketch of the external aspect of the Poduras, I
extract from Lubbock's work a synopsis of the families and genera for
the convenience of the student, adding the names of known American
species, or indications of undescribed native forms.

SMYNTHURIDÆ.--Body globular or ovoid; thorax and abdomen forming one
mass; head vertical or inclined; antennæ of four or eight segments. Eyes
eight on each side, on the top of the head. Legs long and slender.
Saltatory appendage with a supplementary segment.

Smynthurus. Antennæ four-jointed, bent at the insertion of the fourth,
which is nearly as long as the other three, and appears to consist of
many small segments. No conspicuous dorsal tubercles. (In this country
Fitch has described five species: S. arvalis, elegans, hortensis,
Novæboracensis, and signifer. Figure 156 represents a species found in
Maine.)

Dicyrtoma. Antennæ eight-jointed, five before, three after the bend. Two
dorsal tubercles on the abdomen.

Papirius.[12] Antennæ four-jointed, without a well-marked elbow, and
with a short terminal segment offering the appearance of being
many-jointed.

PODURIDÆ.--This family comprises those species of the old genus Podura,
in which the mouth has mandibles [also maxillæ and a labium], and the
body is elongated, with a more or less developed saltatory appendage at
the posterior extremity.

Orchesella. Segments of the body unequal in size, more or less thickly
clothed with clubbed hairs. Antennæ long, six-jointed. Eyes six in
number on each side, arranged in the form of an S. (One or two beautiful
species live about Salem.)

[Illustration: 168. Degeeria.]

Degeeria. Segments of the body unequal in size, more or less thickly
clothed by clubbed hairs. Antennæ longer than the head and thorax,
filiform, four-jointed. Eyes eight in number on each side of the head.
(Two species, Degeeria decem-fasciata, Pl. 10, Figs. 2, 3, and D.
purpurascens, Figs. 4, 5, are figured in the "Guide to the Study of
Insects." Figure 168 represents a species found in Salem, Mass., closely
allied to the European D. nivalis. Five species are already known in New
England.)

Seira. Body covered with scales. Antennæ four-jointed; terminal segment
not ringed. Eyes on a dark patch. Thorax not projecting over the head.
Abdominal segments unequal.

Templetonia. Segments of the body subequal, clothed by clubbed hairs,
and provided with scales. Antennæ longer than the head and thorax,
five-jointed, with a small basal segment, and with the terminal portion
ringed.

Isotoma. Four anterior abdominal segments subequal, two posterior ones
small; body clothed with simple hairs and without scales. Antennæ
four-jointed, longer than the head; segments subequal. Eyes seven in
number on each side, arranged in the form of an S. (Three species are
found in Massachusetts, one of which (I. plumbea) is figured on Pl. 10,
Figs. 6, 7, of the "Guide to the Study of Insects," third edition.)

Tomocerus. Abdominal segments unequal, with simple hairs and scales.
Antennæ very long, four-jointed, the two terminal segments ringed. Eyes
seven in number on each side. (The European T. plumbea, Podura plumbea
of authors, is our species, and is common. Fig. 160, greatly enlarged,
copied from Templeton; Fig. 159, side view, see also Fig. 161, where the
mouth-parts are greatly enlarged, the lettering being the same, _md_,
mandibles; _mx_, maxillæ; _mp_, maxillary palpus; _lb_, labium; _lp_,
labial palpus; _lc_, lacinia; _g_, portion ending in three teeth; _l_,
lobe of labium; _sp_, ventral sucking disk; the dotted line's passing
through the body represent the course of the intestine; _b_, end of
tibia, showing the tarsus, with the claw, and two accessory spines; _a_,
third joint of the spring. Fig. 162, lacinia of maxilla greatly
enlarged. Fig. 169, different forms of scales, showing the great
variation in size and form, the narrow ones running into a linear form,
becoming hairs. The markings are also seen to vary, showing, their
unreliable character as test objects, unless a single scale is kept for
use.)

[Illustration: 169. Scales of Tomocerus.]

[Illustration: 170. Lepidocyrtus.]

[Illustration: 171. Scale of Lepidocyrtus.]

Lepidocyrtus. Abdominal segment unequal, with simple hairs and scales.
Antennæ long, four-jointed. Eyes eight in number on each side. (Fig.
170, L. albinos, an European species, from Hardwicke's "Science Gossip."
Fig. 171, a scale. Two species live in New England.)

Podura. Abdominal segments subequal. Hairs simple, no scales. Antennæ
four-jointed, shorter than the head. Eyes eight in number on each side.
Saltatory appendage of moderate length.

[Illustration: 172. Achorutes.]

Achorutes. Abdominal segments subequal. Antennæ short, four-jointed.
Eyes eight in number on each side. Saltatory appendage quite short.

Figure 172 represents a species of this genus very abundant under the
bark of trees, etc., in New England. It is of a blackish lead color;
_a_, end of tibia bearing a tenant hair, with the tarsal joint and large
claw; _b_, spring; _c_, the third joint of the spring, with the little
spine at the base; figure 163, the supposed ovipositor; _a_, the two
blades spread apart; _b_, side view. The mouth-parts in this genus are
much as in Tomocerus, the maxillæ ending in a lacinia and palpus.

[Illustration: 173. Lipura fimetaria.]

The three remaining genera, Lipura, Anurida and Anura, are placed in the
"family" Lipuridæ, which have no spring. Lubbock remarks that "this
family contains as yet only two[13] genera, Lipura (Burmeister), in
which the mouth is composed of the same parts as those in the preceding
genera, and Anura (Gervais), in which the mandibles and maxillæ
disappear." Our common white Lipura is the European L. fimetaria Linn.
(Fig. 173, copied from Lubbock). The site of the spring is indicated by
an oval scar.

[Illustration: 174. 176. 175.

Anurida maritima.]

Figure 174 represents Anurida maritima found under stones between tide
marks at Nantucket. It is regarded the same as the European species by
Lubbock, to whom I had sent specimens for comparison. This genus differs
in the form of the head from Lipura and also wants the terminal upcurved
spines, while the antennæ are much more pointed. The legs (Fig. 175) end
in a large, long, curved claw. On examining specimens soaked in potash,
I have found that the mouth-parts of this species (Fig. 176,) _md_,
mandibles; _mx_, maxillæ; _e_, eyes, and a singular accessory group of
small cells, are like those of Achorutes, as previously noticed by
Laboulbène. The mandibles, like those of other Poduras, end in from
three to six teeth, and have a broad, many-toothed molar surface below.
The maxillæ; end in a tridentate lacinia as usual, though the palpi and
galea I have not yet studied.

The genus Anura may be readily recognized by the mouth ending in an
acutely conical beak, with its end quite free from the head and hanging
down beneath it. The body is short and broad, much tuberculated, while
the antennæ are short and pointed, and the legs are much shorter than in
Lipura, not reaching more than a third of their length beyond the body.
Our common form occurs under the bark of trees.

For the reason that I can find no valid characters for separating these
three genera as a family from the other Poduras, I am inclined to think
that they form, by the absence of the spring, only a subdivision
(perhaps a subfamily) of the Poduridæ.

The best way to collect Poduras is, on turning up the stick or stone on
the under side of which they live, to place a vial over them, allowing
them to leap into it; they may be incited to leap by pushing a needle
under the vial. They may also be collected by a bottle with a sponge
saturated with ether or chloroform. They may be kept alive for weeks by
keeping moist slips of blotting paper in the vial. In this way I have
kept specimens of Degeeria, Tomocerus and Orchesella, from the middle of
December till late in January. During this time they occasionally
moulted, and Tomocerus plumbeus, after shedding its skin, ate it within
a few hours. Poduras feed ordinarily on vegetable matter, such as dead
leaves and growing cryptogamic vegetation. These little creatures can be
easily preserved in a mixture of alcohol and glycerine, or pure alcohol,
though without the glycerine the colors fade.

We have entered more fully in this chapter into the details of structure
than heretofore, too much so, perhaps, for the patience of our readers.
But the study of the Poduras possesses the liveliest interest, since
these lowest of all the six-footed insects may have been among the
earliest land animals, and hence to them we may look with more or less
success for the primitive, ancestral forms of insect life.

FOOTNOTES:

[Footnote 9: Nicolet, in the "Annales de la Societe Entomologique de
France" (tome v, 1847), has given us the most comprehensive essay on the
group, though Latreille had previously published an important essay, "De
l'Organization Exterieure des Thysanoures" in the "Nouvelles Annales du
Museum d'Histoire Naturelle, Paris, 1832," which I have not seen.
Gervais has also given a useful account of them in the third volume of
"Apteres" of Roret's Suite a Buffion,
published in 1844.

The Abbe Bourlet, Templeton, Westwood, and Haliday have published
important papers on the Thysanura; and Meinert, a Danish naturalist, and
Olfers, a German anatomist, have published important papers on the
anatomy of the group. In this country Say and Fitch have described less
than a dozen species, and the writer has described two American species
of Campodea, C. Americana, our common form, and C. Cookei, discovered by
Mr. C. Cooke in Mammoth Cave, while Humbert has described in a French
scientific journal a species of Jupyx (J. Saussurii) from Mexico.]

[Footnote 10: The direct homology of these parts of the head (the
occiput and the epicranium) with Perla, Forficula, etc., seems to me the
best evidence we could have that the Poduræ are not an independent
group. In these most fundamental characters they differ widely from the
Myriopods. I am not aware that this important relation has been
appreciated by observers.]

[Footnote 11: As we descend to the soft, tube-like, suctorial (?) mouth
of Anura, which is said not to have hard mouth-parts, we see the final
point of degradation to which the mouth of the Thysanura is carried. I
think that this gradual degradation of the mouth-parts in this group
indicates that the appendages in these animals are not formed on an
independent type, intermediate, so to speak, between the mandibulate and
haustellate types, but are simply a modification (through disuse) of the
mandibulate type as seen in Neuropterous insects.]

[Footnote 12: Lubbock considers that Papirius should be placed in a
distinct family from Smynthurus, because it wants tracheæ. Their
presence or absence scarcely seems to us to be a family character, as
they are wanting in the Poduridæ, and are not essential to the life of
these animals, while in other respects Papirius seems to differ but
slightly from Smynthurus.]

[Footnote 13: Dr. Laboulbène has recently, and we think with good
reason, separated Anura maritima from the genus Anura, under the name of
Anurida maritima.]




CHAPTER XIII.

HINTS ON THE ANCESTRY OF INSECTS.


[Illustration: 177. Pentastoma.]

[Illustration: 178. Centipede.]

Though our course through the different groups of insects may have
seemed rambling and desultory enough, and pursued with slight reference
to a natural classification of the insects of which we have spoken, yet
beginning with the Hive bee, the highest intelligence in the vast world
of insects, we have gradually, though with many a sudden step, descended
to perhaps the most lowly organized forms among all the insects, the
parasitic mites. While the Demodex is probably the humblest in its
organization of any of the insects we have treated of, there is still
another mite, which, some eminent naturalists continue to regard as a
worm, which is yet lower in the scale. This is the Pentastoma (Fig. 177,
P. tænioides), which lives in the manner of the tape worm a parasitic
life in the higher animals, though instead of inhabiting the alimentary
canal, the worm-like mite takes up its abode in the nostrils and frontal
sinus of dogs and sheep, and sometimes of the horse. At first, however,
it is found in the liver or lungs of various animals, sometimes in man.
It is then in the earliest or larval state, and assumes its true mite
form, being oval in shape, with minute horny jaws adapted for boring,
and with two pairs of legs armed with sharp retractile claws. Such an
animal as this is little higher than some worms, and indeed is lower
than many of them.

We should also not pass over in silence the Centipedes (Fig. 178,
Scolopocryptops sexspinosa) and Galley worms, or Thousand legs and their
allies (Myriopods), which by their long slender bodies, and great number
of segments and feet, vaguely recall the worms. But they, with the
mites, are true insects, as they are born with only three pairs of feet,
as are the mites and ticks, and breathe by tracheæ; and thus a common
plan of structure underlies the entire class of insects.

[Illustration: 179. Young Pauropus.]

[Illustration: 180. Spring-tail.]

[Illustration: 181. Young Julus.]

A very strange Myriopod has been discovered by Sir John Lubbock in
Europe, and we have been fortunate enough to find a species in this
country. It is the Pauropus. It consists, when fully grown, of nine
segments, exclusive of the head, bearing nine pairs of feet. The young
of Pauropus (Fig. 179) is born with three pairs of feet, and in its
general appearance reminds us of a spring-tail (Fig. 180) as may be seen
by a glance at the cut. This six-legged form of Pauropus may also be
compared with the young galley worm (Fig. 181).

[Illustration: 182. Leptus.]

[Illustration: 183. Tardigrade.]

Passing to the group of spiders and mites, we find that the young mites
when first hatched have but three pairs of feet, while their parents
have four, like the spiders. Figure 182 represents the larva (Leptus)
of the red garden mites; while a figure of the "water bear," or
Tardigrade (Fig. 183), is introduced to compare with it, as it bears a
resemblance to the young of the mites, though their young are born with
their full complement of legs, an exception to their nearest allies, the
true mites. Now if we compare these early stages of mites and myriopods
with those of the true six-footed insects, as in the larval Meloë,
Cicada, Thrips and Dragon fly, we shall see quite plainly that they all
share a common form. What does this mean? To the systematist who
concerns himself with the classification of the myriads of different
insects now living, it is a relief to find that all can be reduced to
the comparatively simple forms sketched above. It is to him a proof of
the unity of organization pervading the world of insects. He sees how
nature, seizing upon this archetypal form has, by simple modifications
of parts here and there, by the addition of wings and other organs
wanting in these simple creatures, rung numberless changes in this
elemental form. And starting from the simplest kinds, such as the
Poduras, Spiders, Grasshoppers and May flies, allied creatures which we
now know were the first to appear in the earlier geologic ages, we rise
to the highest, the bees with their complex forms, their diversified
economy and wonderful instincts. In ascending this scale of being, while
there is a progress upwards, the beetles, for instance, being higher
than the bugs and grasshoppers; and the butterflies and moths, on the
whole, being more highly organized than the flies; and while we see the
hymenopterous saw-flies, with their larvæ mimicking so closely the
caterpillars of the butterflies, in the progress from the saw-flies up
to the bees we behold a gradual loss of the lower saw-fly characters in
the Cynips and Chalcid flies, and see in the sand-wasps and true wasps
a constant and accelerating likeness to the bee form. Yet this
continuity of improving organizations is often broken, and we often see
insects which recall the earlier and more elementary forms.

[Illustration: 184. Male Stylops.]

Again, going back of the larval period, and studying the insect in the
egg, we find that nearly all the insects yet observed agree most
strikingly in their mode of growth, so that, for instance, the earlier
stages of the germ of a bee, fly or beetle, bear a remarkable
resemblance to each other, and suggest again, more forcibly than when we
examine the larval condition, that a common design or pattern at first
pervades all. In the light of the studies of Von Baer, of Lamarck and
Darwin, should we be content to stop here, or does this ideal archetype
become endowed with life and have a definite existence, becoming the
ancestral form of all insects, the prototype which gave birth to the
hundreds of thousands of insect forms which are now spread over our
globe, just as we see daily happens where a single aphis may become the
progenitor of a million offspring clustering on the same tree? Is there
not something more than analogy in the two things, and is not the same
life-giving force that evolves a million young Aphides from the germ
stock of a single Aphis in a single season, the same in kind with the
production of the living races of insects from a primeval ancestor? When
we see the Aphis giving origin in one season to successive generations,
the individuals of which may be counted by the million, it is no less
mysterious than that other succession of forms of insect life which has
peopled the globe during the successive chapters of its history. While
we see in one case the origin of individual forms, and cannot explain
what it is that starts the life in the germ and so unerringly guides the
course of the growing embryo, it is illogical to deny that the same
life-giving force is concerned in the production of specific and generic
forms.

[Illustration: 185. Female Stylops.]

Who can explain the origin of the sexes? What is the cause that
determines that one individual in a brood of Stylops, for example (Fig.
184, male; Fig. 185, grub-like female in the body of its host), shall be
but a grub, living as a parasite in the body of its host, while its
fellow shall be winged and as free in its actions as the most highly
organized insect? It is no less mysterious, because it daily occurs
before our eyes. So perhaps none the less mysterious, and no more
discordant with known natural laws may the law that governs the origin
of species seem to those who come after us. Certainly the present
attempts to discover that law, however fatuitous they may seem to many,
are neither illogical, nor, judging by the impetus already given to
biology, or the science of life, labor altogether spent in vain. The
theory of evolution is a powerful tool, when judiciously used, that must
eventually wrest many a secret from the grasp of nature.

But whether true or unproved, the theory of evolution in some shape has
actually been adopted by the large proportion of naturalists, who find
it indispensable in their researches, and it will be used until found
inadequate to explain facts. Notwithstanding the present distrust, and
even fear, with which it is received by many, we doubt not but that in
comparatively few years all will acknowledge that the theory of
evolution will be to biology what the nebular hypothesis is to geology,
or the atomic theory is to chemistry. While the evolution theory is as
yet imperfect, and many objections, some seemingly insuperable, can be
raised against it, it should be borne in mind that the nebular
hypothesis is still comparatively crude and unsatisfactory, though
indispensable as a working theory to the geologist; and in chemistry,
though the atomic theory may not be satisfactorily demonstrated to some
minds until an atom is actually brought to sight, it is yet invaluable
in research.

Many short sighted persons complain that such a theory sets in the
back-ground the idea of a personal Creator; but minds no less devout,
and perhaps a trifle more thoughtful, see the hand of a Creator not less
in the evolution of plants and animals from prëexistent forms, through
natural laws, than in the evolution of a summer's shower, through the
laws discovered by the meteorologist, who looks back through myriads of
ages to the causes that led to the distribution of mountain chains,
ocean currents and trade winds, which combine to produce the necessary
conditions resulting in that shower.

Indeed, to the student of nature, the evolution theory in biology, with
the nebular hypothesis, and the grand law in physics of the correlation
of forces, all interdependent, and revealing to us the mode in which the
Creator of the Universe works in the world of matter, together form an
immeasurably grander conception of the order of creation and its
Ordainer, than was possible for us to form before these laws were
discovered and put to practical use. We may be allowed, then, in a
reverent spirit of inquiry, to attempt to trace the ancestry of the
insects, and without arriving, perhaps, at any certain result, for it is
largely a matter of speculation, point out certain facts, the thoughtful
consideration of which may throw light on this difficult and
embarrassing question.

Without much doubt the Poduras are the lowest of the six-footed insects.
They are more embryonic in their appearance than others, as seen in the
large size of the head compared with the rest of the body, the large,
clumsy legs, and the equality in the size of the several segments
composing the body. In other characters, such as the want of compound
eyes, the absence of wings, the absence of a complete ovipositor, and
the occasional want of tracheæ, they stand at the base of the insect
series. That they are true insects, however, we endeavored to show in
the previous chapter, and that they are neuropterous, we think is most
probable, since not only in the structure of the insect after birth do
they agree with the larvæ of certain neuropters, but, as we have shown
in another place[14] in comparing the development of Isotoma, a Poduran,
with that of a species of Caddis fly, the correspondence throughout the
different embryological stages, nearly up to the time of hatching, is
very striking. And it is a remarkable fact, as we have previously
noticed, that when it begins to differ from the Caddis fly embryo, it
begins to assume the Poduran characters, and its development
consequently in some degree retrogrades, just as in the lice previous to
hatching, as we have shown in a previous chapter, so that I think we are
warranted at present in regarding the Thysanura, and especially the
family of Podarids as degraded neuropters. Consequently the Poduras did
not have an independent origin and do not, perhaps, represent a distinct
branch of the genealogical tree of articulates. While the Poduras may be
said to form a specialized type, the Bristle-tails (Lepisma, Machilis,
Nicoletia and Campodea) are, as we have seen, much more highly
organized, and form a generalized or comprehensive type. They resemble
in their general form the larva of Ephemerids, and perhaps more closely
the immature Perla, and also the wingless cockroaches.

[Illustration: 186. Embryo of Diplax.]

[Illustration: 187. Embryo of Louse.]

Now such forms as these Thysanura, together with the mites and the
singular Pauropus, we cannot avoid suspecting to have been among the
earliest to appear upon the earth, and putting together the facts,
first, of their low organization; secondly, of their comprehensive
structure, resembling the larvæ of other insects; and thirdly, of their
probable great antiquity, we naturally look to them as being related in
form to what we may conceive to have been the ancestor of the class of
insects. Not that the animals mentioned above were the actual ancestors,
but that certain insects bearing a greater resemblance to them than any
others with which we are acquainted, and belonging possibly to families
and orders now extinct, were the prototypes and progenitors of the
insects now known.

[Illustration: 188. Embryo of Spider.]

[Illustration: 189. Embryo of Podura.]

Though the study of the embryology of insects is as yet in its infancy,
still with the facts now in our possession we can state with tolerable
certainty that at first the embryos of all insects are remarkably alike,
and the process of development is much the same in all, as seen in the
figure of Diplax (Fig. 186), the louse (Fig. 187), the spider (Fig. 188)
and the Podura (Fig. 189), and we could give others bearing the same
likeness. We notice that at a certain period in the life of the embryo
all agree in having the head large, and bearing from two to four pairs
of mouth organs, resembling the legs; the thorax is merged in with the
abdomen, and the general form of the embryo is ovate. Now this general
embryonic form characterizes the larva of the mites, of the myriopods
and of the true insects. To such a generalized embryonic form to which
the insects may be referred as the descendants, we would give the name
of _Leptus_, as among Crustacea the ancestral form is referred to
Nauplius, a larval form of the lower Crustacea, and through which the
greater part of the Crabs, Shrimps, Barnacles, water fleas, etc., pass
to attain their definite adult condition. A little water flea was
described as a separate genus, Nauplius, before it was known to be the
larva of a higher water flea, and so also Leptus was thought to be a
mature mite. Accordingly, we follow the usage of certain naturalists in
dealing with the Crustacea, and propose for this common primitive larval
condition of insects the term Leptus.

[Illustration: 190. Zoëa.]

The first to discuss this subject of the ancestry of insects was Fritz
Müller, who in his "Für Darwin,"[15] published in 1863, says, at the end
of his work, "Having reached the Nauplius, the extreme outpost of the
class, retiring farthest into the gray mist of primitive time, we
naturally look round us to see whether ways may not be descried thence
towards other bordering regions. * * * But I can see nothing certain.
Even towards the nearer provinces of the Myriopoda and Arachnida I can
find no bridge. For the Insecta alone, the development of the
Malacostraca [Crabs, Lobsters, Shrimps, etc.] may perhaps present a
point of union. Like many Zoëæ, the Insecta possess three pairs of limbs
serving for the reception of nourishment, and three pairs serving for
locomotion; like the Zoëæ they have an abdomen without appendages; as in
all Zoëæ the mandibles in Insecta are destitute of palpi. Certainly but
little in common, compared with the much which distinguishes these two
animal forms. Nevertheless, the supposition that the Insecta had for
their common ancestor a Zoëa which raised itself into a life on land,
may be recommended for further examination" (p. 140).

Afterwards Hæckel in his "Generelle Morphologie" (1866) and "History of
Creation," published in 1868, reiterates the notion that the insects are
derived from the larva (Zoëa, Fig. 190) of the crabs, though he is
doubtful whether they did not originate directly from the worms.[16]

It may be said in opposition to the view that the insects came
originally from the same early crustacean resembling the larva of a crab
or shrimp, that the differences between the two types are too great, or,
in other words, the homologies of the two classes too remote,[17] and
the two types are each too specialized to lead us to suppose that one
was derived from the other. Moreover, we find through the researches of
Messrs. Hartt and Scudder that there were highly developed insects, such
as May flies, grasshoppers, etc., in the Devonian rocks of New
Brunswick, leading us to expect the discovery of low insects even in the
Upper Silurian rocks. At any rate this discovery pushes back the origin
of insects beyond a time when there were true Zoëæ, as the shrimps and
their allies are not actually known to exist so far back as the
Silurian, not having as yet been found below the coal measures.


The view that the insects were derived from a Zoëa was also sustained by
Friedrich Brauer, the distinguished entomologist of Vienna, in a
paper[18] read in March, 1869. Following the suggestion of Fritz Müller
and Hæckel, he derives the ancestry of insects from the Zoëa of crabs
and shrimps. However, he regards the Podurids as the more immediate
ancestors of the true insects, selecting Campodea as the type of such an
ancestral form, remarking that the "Campodea-stage has for the Insects
and Myriopods the same value as the Zoëa for the Crustacea." He says
nothing regarding the spiders and mites.

At the same time[19] the writer, in criticising Hæckel's views of the
derivation of insects from the Crustacea (ignorant of the fact that he
had also suggested that the insects were possibly derived directly from
the worms, and also independently of Brauer's opinions) declared his
belief that though it seemed premature, after the discovery of highly
organized winged insects in rocks so ancient as the Devonian, and with
the late discovery of a land plant in the Lower Silurian rocks of
Sweden,[20] to even guess as to the ancestry of insects, yet he would
suggest that, instead of being derived from some Zoëa, "the ancestors of
the insects (including the six-footed insects, spiders and myriopods)
must have been worm-like and aquatic, and when the type became
terrestrial we would imagine a form somewhat like the young Pauropus,
which combines in a remarkable degree the characters of the myriopods
and the degraded wingless insects, such as the Smynthurus, Podura, etc.
Some such forms may have been introduced late in the Silurian period,
for the interesting discoveries of fossil insects in the Devonian of New
Brunswick, by Messrs. Hartt and Scudder, and those discovered by Messrs.
Meek and Worthen in the lower part of the Coal Measures at Morris,
Illinois, and described by Mr. Scudder, reveal carboniferous myriopods
(two species of Euphorberia) more highly organized than Pauropus, and a
carboniferous scorpion (Buthus?) closely resembling a species now living
in California, together with another scorpion-like animal, Mazonia
Woodiana, while the Devonian insects described from St. John by Mr.
Scudder, are nearly as highly organized as our grasshoppers and May
flies. Dr. Dawson has also discovered a well developed milleped
(Xylobius) in the Lower Coal Measures of Nova Scotia; so that we must go
back to the Silurian period in our search for the earliest ancestor, or
(if not of Darwinian proclivities) prototype, of insects."

Afterwards[21] the writer, carrying out the idea suggested above,
"referred the ancestry of the Myriopods, Arachnids, and Hexapodous
insects to a Leptus-like terrestrial animal, bearing a vague resemblance
to the Nauplius form among Crustacea, inasmuch as the body is not
differentiated into a head, thorax and abdomen [though the head may be
free from the rest of the body] and there are three pairs of temporary
locomotive appendages. Like Nauplius, which was first supposed to be an
adult Entomostracan, the larval form of Trombidium had been described as
a genus of mites under the name of Leptus (also Ocypete and Astoma) and
was supposed to be adult."

In the same year Sir John Lubbock[22] agrees with Brauer that the groups
represented by Podura and Campodea may have been the ancestors of the
insects, remarking that "the genus Campodea must be regarded as a form
of remarkable interest, since it is the living representative of a
primæval type from which not only the Collembola (Podura, etc.) and
Thysanura, but the other great orders of insects, have all derived their
origin."

The comparison of the Leptus with the Nauplius, or pre-Zoëal stage of
Crustacea, is much more natural. But here we are met with apparently
insuperable difficulties. While the Nauplius (Fig. 191) has but three
pairs of appendages, which become the two pairs of antennæ and
succeeding pair of limbs of the adult, in the Leptus as the least number
we have five pairs, two of which belong to the head (the maxillæ and
mandibles) and three to the thorax; besides these is a true heed,
distinct from the hinder region of the body. It is evident that the
Leptus fundamentally differs from the Nauplius and begins life on a
higher plane. We reject, therefore, the Crustacean origin of the
insects. Our only refuge is in the worms, and how to account for the
transmutation of any worm with which we are at present acquainted into a
form like the Leptus, with its mandibulated mouth and jointed legs,
seems at first well nigh impossible. We have the faintest possible
indication in the structure of some mites, and of the Tardigrades and
Pentastoma, where there is a striking recurrence, as we may term it, to
a worm-like form, readily noticed by every observer, whatever his
opinion may be on the developmental theory. In the Demodex we see a
tendency of the mite to assume under peculiar circumstances an
elongated, worm-like form. The mouth-parts are aborted (though from what
we know of the embryology of other mites, they probably are indicated
early in embryonic life), while the eight legs are not jointed, and form
simple tubercles. In the Tardigrades, a long step lower, we have
unjointed fleshy legs armed with from two to four claws, but the
mouth-parts are essentially mite in character. A decided worm feature is
the fact that they are hermaphrodites, each individual having ovaries
and spermaries, as is the case with many worms.

[Illustration: 191. Nauplius.]

When we come to the singular creatures of which Pentastoma and
Linguatula are the type, we have the most striking approximation to the
worms in external form, but these are induced evidently by their
parasitic mode of life. They lose the rudimentary jointed limbs which
some (Linguatula especially) have well marked in the embryo, and from
being oval, rudely mite-like in form, they elongate, and only the claws
or simple curved hooks, like those of young tape worms, remain to
indicate the original presence of true jointed legs.

In seeking for the ancestry of our hypothetical Leptus among the worms,
we are at best groping in the dark. We know of no ancestral form among
the true Annelides, nor is it probable that it was derived from the
intestinal worms. The only worm below the true Annelides that suggests
any remote analogy to the insects is the singular and rare Peripatus,
which lives on land in warm climates. Its body, not divided into rings,
is provided with about thirty pairs of fleshy tubercles, each ending in
two strong claws, and the head is adorned with a pair of fleshy
tubercles. It is remotely possible that some Silurian land worm, if any
such existed, allied to our living Peripatus, may have been the ancestor
of a series of types now lost which resulted in an animal resembling the
Leptus.

[Illustration: 192. Platygaster error.]

We may, however, as bearing upon this difficult question, cite some
remarkable discoveries of Professor Ganin, a Russian naturalist, on the
early stages of certain ichneumon parasites, which show some worm
features in their embryonic development. In a species of Platygaster
(Fig. 192, P. error of Fitch), which is a parasite on a two-winged gall
fly, the earliest stage observed after the egg is laid is that in which
the egg contains a single cell with a nucleus and nucleolus. Out of this
cell (Fig. 193 _A_, _a_) arise two other cells. The central cell (_a_)
gives origin to the embryo. The two outer ones multiply by subdivision
and form the embryonal membrane, or "amnion," which is a provisional
envelope and does not assist in building up the body of the germ. The
central single cell, however, multiplies by the subdivision of its
nucleus, thus building up the body of the germ. Figure 193 _B_, _g_,
shows the yolk or germ just forming out of the nuclei (_a_) and _b_, the
peripheral cells of the blastoderm skin, or "amnion." Figure 193 _C_
shows the yolk transformed into the embryo (_g_), with the outer layer
of blastodermic cells (_b_). The body of the germ is infolded, so that
the embryo appears bent on itself. Figure 193 _D_ shows the embryo much
farther advanced, with the two pairs of lobes (_md_, rudimentary
mandibles; _d_, rudimentary pad-like organs, seen in a more advanced
stage in _E_), and the bilobate tail (_st_). Figure 194 (_m_, mouth;
_at_, rudimentary antennæ; _md_, mandibles; _d_, tongue-like appendages;
_st_, anal stylets; the subject of this figure is of a different species
from the insect previously figured, which, however, it closely
resembles) shows the first larva stage after leaving the egg. This
strange form, the author remarks, would scarcely be thought an insect,
were not its origin and farther development known, but rather a
parasitic Copepodous crustacean, whence he calls this the Cyclops-like
stage. In this condition it clings to the inside of its
host by means of its hook-like jaws (_md_), moving about like a Cestodes
embryo with its well known six hooks. The tail moves up and down, and is
of but little assistance in its efforts to change its place. Singularly
enough, the nervous, vascular, and respiratory systems (tracheæ) are
wanting, and the alimentary canal is a blind sac, remaining in an
indifferent, or unorganized state. How long it remains in this state
could not be ascertained.

[Illustration: 193. Development of Platygaster.]

[Illustration: 194. First Larva of Platygaster.]

[Illustration: 195. Second Larva of Platygaster.]

The second larval stage (Fig. 195; _oe_, oesophagus; _ng_,
supra-oesophageal ganglion; _n_, nervous cord; _ga_, and _g_, genital
organs; _ms_, band of muscles) is attained by means of a moult, as usual
in the metamorphoses of insects. With the change of skin the larva
entirely changes its form. So-called hypodermic cells are developed. The
singular tail is dropped, the segments of the body disappear, and the
body grows oval, while within begins a series of remarkable changes,
like the ordinary development of the embryo of most other insects within
the egg. The cells of the hypodermis multiply greatly, and lie one above
the other in numerous layers. They give rise to a special primitive
organ closely resembling the "primitive band" of all insect embryos. The
alimentary canal is made anew, and the nervous and vascular systems now
appear, but the tracheæ are not yet formed. It remains in this state for
a much longer period than in the previous stage.

[Illustration: 196. Third Larva of Polynema.]

The third larval form only a few live to reach. This is of the usual
long, oval form of the larvæ of the ichneumons, and the body has
thirteen segments exclusive of the head. The muscular system has greatly
developed and the larva is much more lively in its motions than before.
The new organs that develop are the air tubes and fat bodies. The
"imaginal disks" or rudimentary portions destined to develop and form
the skin of the adult, or imago, arise in the pupa state, which
resembles that of other ichneumons. These disks are only engaged, in
Platygaster, in building up the rudimentary appendages, while in the
flies (Muscidæ and Corethra) they build up the whole body, according to
the remarkable discovery of Weismann.

Not less interesting is the history of the development of a species of
Polynema, another egg-parasite, which lays its eggs (one, seldom two) in
the eggs of a small dragon fly, Agrion virgo, which oviposits in the
parenchyma of the leaves of waterlilies. The eggs develop as in
Platygaster. The earliest stage of the embryo is very remarkable. It
leaves the egg when very small and immovable, and with scarcely a trace
of organization, being a mere flask-shaped sac of cells.[23] It remains
in this state five or six days.

In the second stage, or Histriobdella-like form, the larva is, in its
general appearance, like the low worm to which Ganin compares it. It may
be described as bearing a general resemblance to the third and fully
developed larval form (Fig. 196, _tg_, three pairs of abdominal
tubercles destined to form the sting; _l_, rudiments of the legs; _fk_,
portion of the fatty body; _at_, rudiments of the antennæ; _fl_,
imaginal disks, or rudiments of the wings). No tracheæ are developed in
the larva, nor do any exist in the imago. (Ganin thinks, that as these
insects are somewhat aquatic, the adult insects flying over the surface
of the water, the wings may act as respiratory organs, like gills.) It
lives six to seven days before pupating, and remains from ten to twelve
days in the pupa state.

The origin of the sting is clearly ascertained. Ganin shows that it
consists of three pairs of tubercles, situated respectively on the
seventh, eighth, and ninth segments of the abdomen (Fig. 196, _tg_). The
labium is not developed from a pair of tubercles, as is usual, but at
once appears as an unpaired, or single organ. The pupa state lasts for
five or six days, and when the imago appears it eats its way through a
small round opening in the end of the skin of its host, the Agrion
larva.

[Illustration: 197. Development of Egg-parasites.]

The development of Ophloneurus, another egg-parasite, agrees with that
of Platygaster and Polynema. This egg-parasite passes its early life in
the eggs of Pieris brassicæ, and two or three live to reach the imago
state, though about six eggs are deposited by the female. The eggs are
oval, and not stalked. The larva is at first of the form indicated by
figure 197 _E_, and when fully grown becomes of a broad oval form, the
body not being divided into segments. It differs from the genera already
mentioned, in remaining within its egg membrane, and not assuming their
strange forms. From the non-segmented, sac-like larva, it passes
directly into the pupa state.

The last egg-parasite noticed by Ganin, is Teleas, whose development
resembles that of Platygaster. It is a parasite in the eggs of Gerris,
the Water Boatman. Figure 197 _A_ represents the egg; _B_, _C_, and _D_,
the first stage of the larva, the abdomen (or posterior division of the
body) being furnished with a series of bristles on each side. (_B_
represents the ventral, _C_ the dorsal, and _D_ the profile view; _at_,
antennæ; _md_, hook-like mandibles; _mo_, mouth; _b_, bristles; _m_,
intestine; _sw_, the tail; _ul_, under lip or labium.) In the second
larval stage, which is oval in form, and not segmented, the primitive
band is formed.

In concluding the account of his remarkable discoveries, Ganin draws
attention to the great differences in the formation of the eggs and the
germs of these parasites from what occurs in other insects. The egg has
no nutritive cells; the formation of the primitive band, usually the
first indication of the germ, is retarded till the second larval stage
is attained; and the embryonal membrane is not homologous with the
so-called "amnion" of other insects, but may possibly be compared with
the skin developed on the upper side of the low, worm-like acarian,
Pentastomum, and the "larval skin" of the embryos of many low Crustacea.
He says, also, that we cannot, perhaps, find the homologues of the
provisional organs of the larvæ, such as the singularly shaped antennæ,
the claw-like mandibles, the tongue-or ear-like appendages, in other
Arthropoda (insects and Crustacea); but that they may be found in the
parasitic Lernæan crustaceans, and in the leeches, such as Histriobella.
He is also struck by the similarity in the development of these
egg-parasites to that of a kind of leech (Nephelis), the embryo of which
is provided with ciliæ, recalling the larva of Teleas (Fig. 197 _B_,
_C_), while in the true leeches (Hirudo) the primitive band is not
developed until after they have passed through a provisional larval
stage.

This complicated metamorphosis of the egg-parasites, Ganin also compares
to the so-called "hyper-metamorphosis" of certain insects (Meloë,
Sitaris, and the Stylopidæ) made known by Siebold, Newport and Fabre,
and he considers it to be of the same nature.

He also, in closing, compares such early larval forms as those given in
figures 193 _E_ and 194, to the free swimming Copepoda. Finally, he says
a few words on the theory of evolution, and remarks "there is no doubt
that, if a solution of the questions arising concerning the genealogical
relations of different animals among themselves is possible, comparative
embryology will afford the first and truest principles." He modestly
suggests that the facts presented in his paper will widen our views on
the genetic relations of the insects to other animals, and refers to the
opinion first expressed by Fritz Müller (Für Darwin, p. 91), and
endorsed by Hæckel in his "Generelle Morphologie," that we must seek for
the ancestors of insects and Arachnida in the Zoëa form of Crustacea. He
cautiously remarks, however, that "the embryos and larvæ observed by me
in the egg-parasites open up a new and wide field for a whole series of
such considerations; but I will suppress them, since I am firmly
convinced that a theory, which I build up to-day, can easily be
destroyed with some few facts which I learn to-morrow. Since comparative
embryology as a science does not yet exist, so do I think that all
genetic theories are too premature, and without a strong scientific
foundation."

The writer is perhaps less cautious, but he cannot refrain from making
some reflections suggested by the remarkable discoveries of Ganin. In
the first place, these facts bear strongly on the theory of evolution by
"acceleration and retardation." In the history of these early larval
stages we see a remarkable acceleration in the growth of the embryo. A
simple sac of unorganized cells, with a half-made intestine, so to
speak, is hatched, and made to perform the duty of an ordinary, quite
highly organized larva. Even the formation of the "primitive band,"
usually the first indication of the organization of the germ, is
postponed to a comparatively late period in larval life. The different
anatomical systems, _i.e._, the heart with its vessels, the nervous
system and the respiratory system (tracheæ), appear at longer or shorter
intervals, while in one genus the tracheæ are not developed at all. Thus
some portions of the animal are accelerated in their development more
than others, while others are retarded, and in some species certain
organs are not developed at all. Meanwhile all live in a fluid medium,
with much the same habits, and surrounded with quite similar physical
conditions.

The highest degree of acceleration is seen in the reproductive organs
of the Cecidomyian larva of Miastor, which produces a summer brood of
young, alive, and living free in the body of the child-parent; and in
the pupa of Chironomus, which has been recently shown by Von Grimm, a
fellow countryman of Ganin, to produce young in the spring, while the
adult fly lays eggs in the autumn in the usual manner. This is in fact a
true virgin reproduction, and directly comparable to the alternation of
generations observed in the jelly fishes, in Salpa, and certain
intestinal worms. We can now, in the light of the researches of Siebold,
Leuckart, Ganin and others, trace more closely than ever the connection
between simple growth and metamorphosis, and metamorphosis and
parthenogenesis, and perceive that they are but the terms of a single
series. By the acceleration in the development of a single set of organs
(the reproductive), no more wonderful than the acceleration and
retardation of the other systems of organs, so clearly pointed out in
the embryos of Platygaster and its allies, we see how parthenogenesis
under certain conditions may result. The barren Platygaster larva, the
fertile Cecidomyia larva, the fertile Aphis larva, the fertile
Chironomus pupa, the fertile hydroid polype, and the fertile adult queen
bee are simply animals in different degrees of organization, and with
reproductive systems differing not in quality, but in the greater or
less rapidity of their development as compared with the rest of the
body.

Another interesting point is, that while the larvæ vary so remarkably in
form, the adult ichneumon flies are remarkably similar to one another.
Do the differences in their larval history seem to point back to certain
still more divergent ancestral forms?

These remarkable hyper-metamorphoses remind us of the metamorphosis of
the embryo of Echinoderms into the Pluteus-and Bipinnaria-forms of the
starfish, sea urchins and Holothurians;[24] of the Actinotrocha-form
larva of the Sipunculoid worms; of the Tornaria into Balanoglossus, the
worm; of the Cercaria-form larva of Distoma; of the Pilidium-form larva
of Nemertes; and the larval forms of the leeches;[25] as well as the
mite Pentastomum, and certain other aberrant mites, such as Myobia.

While Fritz Müller and Dohrn have considered the insects as having
descended from the Crustacea (some primitive zoëa-form), and Dohrn has
adduced the supposed zoëa-form larva of these egg-parasites as a proof,
we cannot but think, in a subject so purely speculative as the ancestry
of animals, that the facts brought out by Ganin tend to confirm our
theory, that the ancestry of all the insects (including the Arachnids
and Myriopods) should be traced directly to the worms. The development
of the degraded, aberrant Arachnidan Pentastomum accords, in some
important respects, with that of the intestinal worms. The Leptus-form
larva of Julus, with its strange embryological development, in some
respects so like that of some worms, points in that direction, as
certainly as does the embryological development of the egg-parasite
Ophioneurus. The Nauplius form of the embryo or larva of nearly all
Crustacea, also points back to the worms as their ancestors, the
divergence having perhaps originated, as we have suggested, in the
Rotatoria.

While the Crustacea may have resulted from a series of prototypes
leading up from the Rotifers (Fig. 198), it is barely possible that one
of these creatures may have given rise to a form resulting in two series
of beings, one leading to the Leptus form, the other to the Nauplius.
For the true Annelides (Chætopods) are too circumscribed and homogeneous
a group to allow us to look to them for the ancestral forms of insects.
But that the insects may have descended from some low worms is not
improbable when we reflect that the Syllis and allied genera of
Annelides bear appendages consisting of numerous joints; indeed, the
strange Dujardinia rotifers, figured by Quatrefages, in its general form
is remarkably like the larva of Chloëon. It has a quite distinct head,
bearing five long, slender, jointed antennæ, and but eight or nine rings
to the body, which ends in two long, many jointed appendages exactly
like the tentacles. Quatrefages adds, that its movements are usually
slow, but "when it wishes to move more rapidly, it moves its body
alternately up and down with much vivacity, and shoots forwards by
bounds, so to speak, a little after the manner of the larvæ of the
mosquito" (Histoire Naturelle des Annelés, Tome 2, p. 69). The gills of
aquatic insects only differ from those of worms in possessing tracheæ,
though the gills of the Crustacea may be directly compared with those of
insects.

[Illustration: 198. A Rotifer.]

But when once inside the circle of the class of insects the ground is
firmer, as our knowledge is surer. Granting now that the Leptus-like
ancestor of the six-footed insects has become established, it is not so
difficult to see how the Poduræ and finally a form like Campodea
appeared. Aquatic forms resembling the larva of the Ephemeræ, Perlæ and,
more remotely, the Forficulæ and white ants of to-day were probably
evolved with comparative suddenness. Given the evolution of forms like
the earwigs (Forficula), cockroaches and white ants (Termes), the latter
of which abounded in the coal period, and it was not a great step
forward to the evolution of the Dragonflies, the Psocus, the Chrysopa,
the lice or parasitic Hemiptera, together with Thrips, thus forming the
establishment of lines of development leading up to those Neuroptera
with a complete metamorphosis, and finally to the grasshoppers and other
forms of Orthoptera, together with the Hemiptera.

[Illustration: 199. Chrysopa.]

[Illustration: 200. Panorpa.]

We have thus advanced from wingless to winged forms, _i. e._, from
insects without a metamorphosis to those with a partial metamorphosis
like the Perlas; to the May flies and Dragon flies, in which the adult
is still more unlike the larva; to the Chrysopa (Fig. 199) and Forceps
Tails (Panorpa, Fig. 200) and Caddis flies, in which, especially the
latter, the metamorphosis is complete, the pupa being inactive and
enclosed in a cocoon.

[Illustration: 201. Embryo of Diplax.]

Having assumed the creation of our Leptus by evolutional laws, we must
now account for the appearance of tracheæ and those organs so dependent
on them, the wings, which, by their presence and consequent changes in
the structure of the crust of the body, afford such distinctive
characters to the flying insects, and raise them so far above the
creeping spiders and centipedes. Our Leptus at first undoubtedly
breathed through the skin, as do most of the Poduras, since we have been
unable to find tracheæ in them, nor even in the prolarva of a genus of
minute ichneumon egg parasites, nor in the Linguatulæ and Tardigrades,
and some mites, such as the Itch insect and the Demodex, and other
Acari. In the Myriopod, Pauropus, Lubbock was unable to find any traces
of tracheæ. If we examine the embryo of an insect shortly before birth,
as in the young Dragon fly (figure 201, the dotted line _t_ crosses the
rudimentary tracheæ), we find it to consist of two simple tubes with
few branches, while there are no stigmata, or breathing holes, to be
seen in the sides of the body. This fact sustains the view of
Gegenbaur[26] that at first the tracheæ formed two simple tubes in the
body-cavity, and that the primary office of these tubes was for
lightening the body, and that their function as respiratory tubes was a
secondary one. The aquatic Protoleptus, as we may term the ancestor of
Leptus, may have had such tubes as these, which acted like the swimming
bladder of fishes for lightening the body, as suggested by Gegenbaur. It
is known that the swimming bladder of fishes becomes developed into the
lungs of air-breathing vertebrates and man himself. As our Leptus
adopted a terrestrial life and needed more air, a connection was
probably formed by a minute branch on each side of the body with some
minute pore (for such exist, whose uses are as yet unknown) through the
skin, which finally became specialized into a stigma, or breathing pore;
and from the tracheal system being closed, we now have the open tracheal
system of land insects.

The next inquiry is as to the origin of the wings. Here the question
arises if wingless forms are exceptional among the winged insects, and
the loss of wings is obviously dependent on the habits (as in the lice),
and environment of the species (as in beetles living on islands, which
are apt to lose the hinder pair of wings), why may not their acquisition
in the first place have been due to external agencies; and, as they are
suddenly discarded, why may they not have suddenly appeared in the first
place? In aquatic larvæ there are often external gill-like organs, being
simple sacs permeated by tracheæ (as in Agrion, Fig. 129, or the May
flies). These organs are virtually aquatic wings, aiding the insect in
progression as well as in aërating the blood, as in the true wings. They
are very variable in position, some being developed at the extremity of
the abdomen, as in Agrion, or along the sides, as in the May flies, or
filiform and arranged in tufts on the under side of the body, as in
Perla; and the naturalist is not surprised to find them absent or
present in accordance with the varying habits of the animal. For
example, in the larvæ of the larger Dragon flies (Libellula, etc.) they
are wanting, while in Agrion and its allies they are present.

Now we conceive that wings formed in much the same way, and with no more
disturbance, so to speak, to the insect's organization, appeared during
a certain critical period in the metamorphosis of some early insect. As
soon as this novel mode of locomotion became established we can easily
see how surrounding circumstances would favor their farther development
until the presence of wings became universal. If space permitted us to
pursue this interesting subject farther, we could show how invariably
correlated in form and structure are the wings of insects to the varied
conditions by which they are surrounded, and which we are forced to
believe stand in the relation of cause to effect. Again, why should the
wings always appear on the thorax and on the upper instead of the under
side? As this is the seat of the centre of gravity, it is evident that
cosmical laws as well as the more immediate laws of biology determine
the position and nature of the wings of an insect.

Correlated with the presence of wings is the wonderful differentiation
of the crust, especially of the thorax, where each segment consists of a
number of distinct pieces; while in the spiders and Myriopods the
segments are as simple as in the abdominal segments of the winged
insect. It is not difficult here to trace a series leading up from the
Poduras, in which the segments are like those of spiders, to the
wonderful complexity of the parts in the thoracic segments of the
Lepidoptera and Hymenoptera.

In his remarks "On the Origin of Insects,"[27] Sir John Lubbock says, "I
feel great difficulty in conceiving by what natural process an insect
with a suctorial mouth like that of a gnat or butterfly could be
developed from a powerfully mandibulate type like the Orthoptera, or
even from the Neuroptera." Is it not more difficult to account for the
origin of the mouth-parts at all? They are developed as tubercles or
folds in the tegument, and are homologous with the legs. Figure 186
shows that the two sorts of limbs are at one time identical in form and
relative position. The thought suggests itself that these long, soft,
finger-like appendages may have been derived from the tentacles of the
higher worms, but the grounds for this opinion are uncertain. At any
rate, the earliest form of limb must have been that of a soft tubercle
armed with one, or two, or many terminal claws, as seen in aquatic
larvæ, such as Chironomus (Fig. 202), Ephydra (Fig. 203 _a_, _b_, _c_,
pupa) and many others. As the Protoleptus assumed a terrestrial life and
needed to walk, the rudimentary feet would tend to elongate, and in
consequence need the presence of chitine to harden the integument, until
the habit of walking becoming fixed, the necessity of a jointed
structure arose. After this the different needs of the offspring of such
an insect, with their different modes of taking food, vegetable or
animal, would induce the diverse forms of simple, or raptorial, or
leaping or digging limbs. A peculiar use of the anterior members, as
seen in grasping the food and conveying it to the mouth (perhaps
originally a simple orifice with soft lips, as in Peripatus), would tend
to cause such limbs to be grouped together, to concentrate around the
mouth-opening, and to be directed constantly forwards. With use, as in
the case of legs, these originally soft mouth-feet would gradually
harden at the extremities, until serviceable in biting, when they would
become jaws and palpi. Given a mouth and limbs surrounding it, and we at
once have a rude head set off from the rest of the body. And in fact
such is the history of the development of these parts in the embryo. At
first the head is indicated by the buds forming the rudiments of limbs;
the segments to which they are attached do not form a true head until
after the mouth-parts have attained their jaw-like characters, and it is
not until the insect is about to be hatched, that the head is definitely
walled in.

[Illustration: 202. Foot of Chironomus.]

[Illustration: 203. Ephydra.]

We have arrived, then, at our Leptus, with a head bearing two pairs of
jaws. The spiders and mites do not advance beyond this stage. But in the
true insects and Myriopods, we have the addition of special sense
organs, the antennæ, and another pair of appendages, the labial palpi.
It is evident that in the ancestor of these two groups the first pair of
appendages became early adapted for purely sensory purposes, and were
naturally projected far in advance of the mouth, forming the antennæ.

Before considering the changes from the mandibulate form of insects to
those with mouth parts adapted for piercing and sucking, we must
endeavor to learn how far it was possible for the caterpillar or maggot
to become evolved from the Leptus-like larvæ of the Neuroptera,
Orthoptera, Hemiptera and most Coleoptera. I may quote from a previous
article[28] a few words in relation to two kinds of larvæ most prevalent
among insects. "There are two forms of insectean larvæ which are pretty
constant. One we call _leptiform_, from its general resemblance to the
larvæ of the mites (Leptus). The larvæ of all the Neuroptera, except
those of the Phryganeidæ and Panorpidæ (which are cylindrical and
resemble caterpillars), are more or less leptiform, _i. e._, have a
flattened or oval body, with large thoracic legs. Such are the larvæ of
the Orthoptera and Hemiptera, and the Coleoptera (except the
Curculionidæ; possibly the Cerambycidæ and Buprestidæ, which approach
the maggot-like form of the larvæ of weevils). On the other hand, taking
the caterpillar or bee larva, with their cylindrical, fleshy bodies, in
most respects typical of larval forms of the Hymenoptera, Lepidoptera
and Diptera, as the type of the _cruciform_ larva, etc. * * * The larvæ
of the earliest insects were probably leptiform, and the cruciform
condition is consequently an acquired one, as suggested by Fritz
Müller."[29] It seems that these two sorts of larvæ had also been
distinguished by Dr. Brauer in the article already referred to, with
which, however, the writer was unacquainted at the time of writing the
above quoted article. The similar views presented may seem to indicate
that they are founded in nature. Dr. Brauer, after remarking that the
Podurids seemed to fulfil Hæckel's idea of what were the most primitive
insects, and noticing how closely they resemble the larvæ of Myriopods,
says, "specially interesting are those forms among the Poduridæ which
are described as Campodea and Japyx, since the larvæ of a great number
of insects may be traced back to them"; but he adds, and with this view
we are unable to agree, "while others, the caterpillar-like forms
(Raupenform), resulted from them by a retrograde process, and also
the still lower maggot-like forms. While on the one hand Campodea, with
its abdominal feet, and the larva of Lithobius are related, so on the
other the Lepismatidæ, which are very near the Blattariæ, are nearly
related to the Myriopods, since their abdominal segments often bear
appendages (Machilis). The Campodea-form appears in most of the
Pseudoneuroptera [Libellulids, Ephemerids, Perlids, Psocids and Termes],
Orthoptera, Coleoptera, Neuroptera, perhaps modified in the Strepsiptera
[Stylops and Xenos] and Coccidæ in their first stage of development, and
indeed in many of these at their first moult." Farther on he says, "A
larger part of the most highly developed insects assume another
larva-form, which appears not only as a later acquisition, through
accommodation with certain definite relations, but also arises as such
before our eyes. The larvæ of butterflies and moths, of saw flies and
Panorpæ, show the form most distinctly, and I call this the caterpillar
form (Raupenform). That this is not the primitive form, but one later
acquired, we see in the beetles. The larvæ of Meloë and Sitaris in their
fully grown condition possess the caterpillar form, but the new born
larvæ of these genera show the Campodea form. The last form is lost as
soon as the larva begins its parasitic mode of life. * * * The larger
part of the beetles, the Neuroptera in part, the bees and flies (the
last with the most degraded maggot form) possess larvæ of this second
form." He considers that the caterpillar form is a degraded Campodea
form, the result of its stationary life in plants or in wood.

[Illustration: Pl 2. EXAMPLES OF LEPTIFORM LARVÆ.

EXPLANATION OF PLATE 2. Figure 1, different forms of Leptus; 2, Diplax;
3, Coccinella larva; 4, Cicada larva; 5, Cicindela larva; 6, Ant Lion;
7, Calligrapha larva; 8, Aphis larva; 9, Hemerobius larva; 10, Glyrinua
larva; 11, Carabid larva; 12, Meloë larva.]

[Illustration: Pl 3. EXAMPLES OF ERUCIFORM LARVÆ.

EXPLANATION OF PLATE 3. Figure 1. Panorpa larva; 2, Phryganea larva; 3,
Weevil larva; 4, third larva of Meloë; 5, Chionea larva; 6, Carpet Worm;
7, Phora larva; 8, Wheat Caterpillar; 9, Sphinx Caterpillar; 10,
Acronycta? larva; 11, Saw Fly larva; 12, Abia Saw Fly larva; 13,
Halictus larva; 14, Andrena larva.]

[Illustration: 204. Tipula Larva.]

For reasons which we will not pause here to discuss, we have always
regarded the eruciform type of larva as the highest. That it is the
result of degradation from the Leptus or Campodea form, we should be
unwilling to admit, though the maggots of flies have perhaps retrograded
from such forms as the larvæ of the mosquitoes and crane flies
(Tipulids, Fig. 204).

That the cylindrical form of the bee grub and caterpillar is the result
of modification through descent is evident in the caterpillar-like form
of the immature Caddis fly (Pl. 3, fig. 2). Here the fundamental
characters of the larva are those of the Corydalus and Sialis and
Panorpa, types of closely allied groups. The features that remind us of
caterpillars are superadded, evidently the result of the peculiar
tube-inhabiting habits of the young Caddis fly. In like manner the
caterpillar-form is probably the result of the leaf-eating life of a
primitive Leptiform larva. In like manner the soft-bodied maggot of the
weevil is evidently the result of its living habitually in cavities in
nuts and fruits. Did the soft, baggy female Stylops live exposed, like
its allies in other families, to an out-of-doors life, its skin would
inevitably become hard and chitinous. In these and multitudes of other
cases the adaptation of the form of the insect to its mode of life is
one of cause and effect, and not a bit less wonderful after we know what
induced the change of form.

Having endeavored to show that the caterpillar is a later production
than the young, wingless cockroach, with which geological facts
harmonize, we have next to account for the origin of a metamorphosis in
insects. Here it is necessary to disabuse the reader's mind of the
prevalent belief that the terms larva, pupa and imago are fixed and
absolute. If we examine at a certain season the nest of a humble bee, we
shall find the occupants in every stage of growth from the egg to the
pupa, and even to the perfectly formed bee ready to break out of its
larval cell. So slight are the differences between the different stages
that it is difficult to say where the larval stage ends and the pupa
begins, so also where the pupal state ends and the imago begins. The
following figures (205-208) will show four of the most characteristic
stages of growth, but it should be remembered that there are
intermediate stages between. Now we have noticed similar stages in the
growth of a moth, though a portion of them are concealed beneath the
hard, dense chrysalis skin. The external differences between the larval
and pupal states are fixed for a large part of the year in most
butterflies and moths, though even in this respect there is every
possible variation, some moths or butterflies passing through their
transformations in a few weeks, others requiring several months, while
still others take a year, the majority of the moths living under ground
in the pupa state for eight or nine months. The stages of metamorphosis
in the Diptera are no more suddenly acquired than in the bee or
butterfly. In all these insects the rudiments of the wings, legs, and
even of the ovipositor of the adult exist in the young larva. We have
found somewhat similar intermediate stages in the metamorphoses of the
beetles. The insects we have mentioned are those with a "complete
metamorphosis." We have seen that even in them the term "complete" is a
relative and not absolute expression, and that the terms larva and pupa
are convenient designations for states varying in duration, and assumed
to fulfil certain ends of existence, and even then dependent on length
of seasons, variation in climate, and even on the locality. When we
descend to the insects with an "incomplete" metamorphosis, as in the May
fly, we find that, as in the case of Chloëon, Sir John Lubbock has
described twenty-one stages of existence, and let him who can say where
the larval ends and the pupal or imaginal stages begin. So in a stronger
sense with the grasshopper and cockroach. The adult state in these
insects is attained after a number of moults of the skin, during each of
which the insect gradually draws nearer to the final winged form. But
even the so-called pupæ, or half winged individuals known not to be
adult, in some cases feel the sexual impulse, while a number of species
in each of the families represented by these two insects never acquire
wings.

[Illustration: 205. Larva. 206. Semi-pupa.

207. Advanced Semi-pupa. 208. Pupa.

EARLY STAGES OF THE HUMBLE BEE.]


Still how did the perfect metamorphosis arise? We can only answer this
indirectly by pointing to the Panorpa and Caddis flies, with their
nearly perfect metamorphosis, though more nearly allied otherwise to
those Neuroptera with an incomplete metamorphosis, as the lace-winged
fly, than the insects of any other suborder. If, among a group of
insects such as the Neuroptera, we find different families with all
grades of perfection in metamorphosis, it is possible that larger and
higher groups may exist in which these modes of metamorphosis may be
fixed and characteristic of each. Had we more space for the exposition
of many known facts, the sceptic might perceive that by observing how
arbitrary and dependent on the habits of the insects are the
metamorphoses of some groups, the fixed modes of other and more general
groups may be seen to be probably due to biological causes, or in other
words have been acquired through changes of habits or of the temperature
of the seasons and of climates. Many facts crowd upon us, which might
serve as illustrations and proofs of the position we have taken. For
instance, though we have in tropics rainy and dry seasons when, in the
latter, insects remain quiescent in the chrysalis state as in the
temperate and frigid zones, yet did not the change from the earlier ages
of the globe, when the temperature of the earth was nearly the same the
world over, to the times of the present distribution of heat and cold in
zones, possibly have its influence on the metamorphoses of insects and
other animals? It is a fact that the remains of those insects with a
complete metamorphosis (the bees, butterflies and moths, flies and
beetles) abound most in the later deposits, while those with an
incomplete metamorphosis are fewer in number and the earliest to appear.
Again, certain groups of insects are not found in the polar regions.
Their absence is evidently due to the adverse climatic conditions of
those regions. The development of the same groups is striking in the
tropics, where the sum of environing conditions all tend to favor the
multiplication of insect forms.

It should be observed that some insects, as the grasshopper, for
example, as Müller says, "quit the egg in a form which is distinguished
from that of the adult insect almost solely by the want of wings," while
the freshly hatched young of the bee, we may add, is farthest from the
form of the adult. It is evident that in the young grasshoppers, the
metamorphoses have been passed through, so to speak, in the egg, while
the bee larva is almost embryonic in its build. The helpless young
maggot of the wasp, which is fed solely by the parent, may be compared
to the human infant, while the lusty young grasshopper, which
immediately on hatching takes to the grass or clover field with all the
enthusiasm of a duckling to its native pond, may be likened to that
young feathered mariner. The lowest animals, as a rule, are at birth
most like the adult. So with the earliest known crustacea. The king
crabs, and in all probability the primeval trilobites, passed through
their metamorphoses chiefly in the egg. So in the ancient Nebaliads
(Peltocaris, Discinocaris and Ceratiocaris), if we may follow the
analogy of the recent Nebalia, the young probably closely resembled the
adult, while the living crabs and shrimps usually pass through the most
marked metamorphoses. Among the worms, the highest, and perhaps the most
recent forms, pass through the most remarkable metamorphoses.

[Illustration: 209. Jaws of Ant Lion.]

Another puzzle for the evolutionist to solve is how to account for the
change from the caterpillar with its powerful jaws, to the butterfly
with its sucking or haustellate mouth-parts. We shall best approach the
solution of this difficult problem by a study of a wide range of facts,
but a few of which can be here noticed. The older entomologists divided
insects into haustellate or suctorial, and mandibulate or biting
insects, the butterfly being an example of one, and the beetle serving
to illustrate the other category. But we shall find in studying the
different groups that these are relative and not absolute terms. We find
mandibulate insects with enormous jaws, like the Dytiscus, or Chrysopa
larva or ant lion, perforated, as in the former, or enclosing, as in the
latter two insects, the maxillæ (_b_), which slide backward and forward
within the hollowed mandibles (_a_, Fig. 209, jaws of the ant lion),
along which the blood of their victims flows. They suck the blood, and
do not tear the flesh of their prey. The enormous mandibles of the adult
Corydalus are too large for use and, as Walsh observed, are converted
in the male into simple clasping organs. And to omit a number of
instances, in the suctorial Hemiptera or bugs we have different grades
of structure in the mouth-parts. In the biting lice (Mallophaga) the
mouth is mandibulate; in the Thrips it is mandibulate, the jaws being
free, and the maxillæ bearing palpi, while the Pediculi are suctorial,
and the true bugs are eminently so. But in the bed bug it is easy to see
that the beak is made up of the two pairs of jaws, which are simply
elongated and adapted for piercing and sucking. Among the so-called
haustellate insects the mouth-parts vary so much in different groups,
and such different organs separately or combined perform the function of
sucking, that the term haustellate loses its significance and even
misleads the student. For example, in the house fly the tongue (Fig. 210
_l_, the mandibles, _m_, and maxillæ, _mp_, are useless), a fleshy
prolongation of the labium or second maxillæ, is the sucker, while the
mandibles and maxillæ are used as lancets by the horse fly (Fig. 211,
_m_, mandibles, _mx_, maxillæ). The maxillæ in the butterfly are united
to form the sucking tube, while in the bee the end of the labium (Fig.
212) is specially adapted for lapping, not sucking, the nectar of
flowers. But even in the butterfly, or more especially the moth, there
is a good deal of misapprehension about the structure of the so-called
"tongue." The mouth-parts of the caterpillar exist in the moth. The
mandibles of the caterpillar occur in the head of the moth as two small
tubercles (Fig. 213, _m_). They are aborted in the adult. While the
maxillæ are as a rule greatly developed in the moth, in the caterpillar
they are minute and almost useless. The labium or second maxillæ, so
large in the moth, serves simply as a spinneret in the caterpillar. But
we find a great amount of variation in the tongue or sucker of moths,
and in the silk moths the maxillæ are rudimentary, and there is no
tongue, these organs being but little more developed than in the
caterpillar. Figure 213, B, shows the minute blade-like maxilla of the
magnificent Luna moth, an approximation to the originally blade-like
form in beetles and Neuroptera. The maxillæ in this insect are minute,
rudimentary, and of no service to the creature, which does not take
food. In other moths of the same family we have found the maxillæ
longer, and touching at their tips, though too widely separate at base
to form a sucking tube, while in others the maxillæ are curved, and meet
to form a true tube.

[Illustration: 210. Mouth-parts of the House fly.]

[Illustration: 211. Mouth-parts of Horse fly.]

[Illustration: 212. Head of Humble bee.]

[Illustration: 213. Mouth-parts of Moths.]

In the Cecropia moth it is difficult to trace the rudiments of the
maxillæ at all, and thus we have in the whole range of the moths, every
gradation from the wholly aborted maxillæ of the Platysamia Cecropia, to
those of Macrosila cluentius of Madagascar, which form a tongue,
according to Mr. Wallace, nine and a quarter inches in length, probably
to enable their owner to probe the deep nectaries of certain orchids.
These changes in form and size are certainly correlated with important
differences in habits, and the evolutionist can as rightly say that the
structural changes were induced by use and disuse and change of habits
and the environment of the animal, as on the other hand the advocate of
special creation claims that the two are simply correlated, and that is
all we know about it.

[Illustration: 214. Ichneumon Fly.]

Another set of organs, placed on quite another region of the body, unite
to form the sting of the bee, or its equivalent the ovipositor of other
hymenopterous insects, such as the Ichneumon fly (Fig. 214), the "saw"
of the saw fly, and the augur of the Cicada. These are all formed on the
same plan, arising early in the larval stage as three pairs of little
tubercles, which ultimately form long blades, the innermost constituting
the true ovipositor. We have found that one pair of these organs forms
the "spring" of the Podura, and that in these insects it is three
jointed, and thus is morphologically a pair of legs soldered together at
their base. We would venture to regard the ovipositor of insects as
probably representing three pairs of abdominal legs, comparable with
those of the Myriopods, and even, as we have suggested in another place,
the three pairs of jointed spinnerets of spiders. Thus the ovipositor of
the bee has a history, and is not apparently a special creation, but a
structure gradually developed to subserve the use of a defensive organ.

So the organs of special sense in insects are in most cases simply
altered hairs. The hairs themselves are modified epithelial cells. The
eyes of insects, simple and compound, are at first simply epithelial
cells, modified for a special purpose, and even the egg is but a
modified epithelial cell attached to the walls of the ovary, which in
turn is morphologically but a gland. Thus Nature deals in simples, and
with her units of structure elaborates as her crowning work a temple in
which the mind of man, formed in the image of God, may dwell. Her
results are not the less marvellous because we are beginning to dimly
trace the process by which they arise. It should not lessen our awe and
reverence for Deity, if with minds made to adore, we also essay to trace
the movements of His hand in the origin of the forms of life.

Some writers of the evolution school are strenuous in the belief that
the evolution hypothesis overthrows the idea of archetypes, and plans of
structure. But a true genealogy of animals and plants represents a
natural system, and the types of animals, be they four, as Cuvier
taught, or five, or more, are recognized by naturalists through the
study of dry, hard, anatomical facts. Accepting, then, the type of
articulates as founded in nature from the similar modes of development
and points of structure perceived between the worms and the crustacea on
the one hand, and the worms and insects on the other, have we not a
strong genetic bond uniting these three great groups into one grand
subkingdom, and can we not in imagination perceive the successive steps
by which the Creator, acting through the laws of evolution, has built up
the great articulate division of the animal kingdom?

FOOTNOTES:

[Footnote 14: Memoirs of the Peabody Academy of Science, II.
Embryological Studies on Diplax, Perithemis, and the Thysanurus genus
Isotoma. Salem, 1871.]

[Footnote 15: Translated in 1859 by Mr. Dallas under the title "Facts
for Darwin."]

[Footnote 16: "Whether that common stem-form of all the Tracheata
[Insects, Myriopods and Spiders] which I have called Protracheata in my
'General Morphology' has developed directly from the true Annelides
(Coelminthes), or, the next thing to this (_zunachst_), out of
Zoea-form Crustacea (Zoepoda), will be hereafter established only
through a sufficient knowledge and comparison of the structure and mode
of growth of the Tracheata, Crustacea and Annelides. In either case is
the root of the Tracheata, as also of the Crustacea, to be sought in the
group of the true jointed worms (Annelides, Gephyrea and Rotatoria." He
considers the first insect to have appeared after the Silurian period,
viz., in the Devonian.]

[Footnote 17: The Zoëa is born with eight pairs of jointed appendages
belonging to the head, and with no thoracic limbs, while in insects
there are but four pairs of cephalic appendages and three pairs of legs.
Correlated with this difference is the entirely different mode of
grouping the body segments, the head and thorax being united into one
region in the crab, but separate in the insects, the body being as a
rule divided into a head, thorax and abdomen, while these regions are
much less distinctly marked in the crabs, and liable in the different
orders to great variations. The great differences between the Crustacea
and insects are noticeable at an early period in the egg.]

[Footnote 18: Considerations on the Transmutation of Insects in the
Sense of the Theory of Descent. Read before the Imperial
Zoological-botanical Society in Vienna, April 3, 1869.]

[Footnote 19: American Naturalist, vol. 3, p. 45, March, 1869.]

[Footnote 20: See Prof. Torell's discovery of Eophyton Linnæanum, a
supposed land plant allied to the rushes and grasses of our day, in
certain Swedish rocks of Lower Cambrian age. The writer has, through the
kindness of Prof. Torell, seen specimens of these plants in the Museum
of the Geological Survey at Stockholm. Mr. Murray, of the Canadian
Geological Survey, was the first to discover in America (Labrador,
Straits of Belle Isle) this same genus of plants. They are described and
figured by Mr. Billings, who speaks of them as "slender, cylindrical,
straight, reed-like plants," in the "Canadian Naturalist" for August,
1872.

Should the terrestrial nature of these plants be established on farther
evidence, then we are warranted in supposing that there were isolated
patches of land in the Cambrian or Primordial period, and if there was
land there must have been bodies of fresh water, hence there may have
been both terrestrial and aquatic insects, possibly of forms like the
Podurids, May flies, Perlæ, mites and Pauropus of the present day. There
was at any rate land in the Upper Silurian period, as Dr. J. W. Dawson
describes land plants (Psilophyton) from the Lower Heiderberg Rocks of
Gaspe, New Brunswick, corresponding in age with the Ludlow rocks of
England.

We might also state in this connection that Dr. Dawson, the eminent
fossil botanist of Montreal, concludes from the immense masses of carbon
in the form of graphite in the Laurentian rocks of Canada, that "the
Laurentian period was probably an age of most prolific vegetable growth.
* * * Whether the vegetation of the Laurentian was wholly aquatic or in
part terrestrial we have no means of knowing." In 1855, Dr. T. Sterry
Hunt asserted "that the presence of iron ores, not less than that of
graphite, points to the existence of organic life even during the
Laurentian or so-called Azoic period." In 1861 he went farther and
stated his belief in "the existence of an abundant vegetation during the
Laurentian period." The Eophyton in Labrador occurs above the Trilobite
(Paradoxides) beds, while in Sweden they occur below.]

[Footnote 21: In a communication made to the Boston Society of Natural
History, Oct. 17, 1870 (see also "American Naturalist" for Feb. and
Sept., 1871).]

[Footnote 22: On the Origin of Insects, a paper read before the Linnæan
Society of London Nov. 2, 1871, and reported in abstract in "Nature,"
Nov. 9, 1871.]

[Footnote 23: This reminds us (though Ganin does not mention it) of the
development of the embryo of Julus, the Thousand legs, which, according
to Newport, hatches the 25th day after the egg is laid. At this period
the embryo is partially organized, having faint traces of segments, and
is still enveloped in its embryonal membranes and retains its connection
with the shell. In this condition it remains for seventeen days, when it
throws off its embryonal membrane, and becomes detached from the shell.]

[Footnote 24: It is a suggestive fact that these deciduous forms give
way through histolysis to true larval forms, just as in some flies
(Musca vomitoria) the true larval form goes under, and the adult form is
built up from the imaginal disks of the larva. In an analogous manner
the deciduous, pluteus-condition of the young Echinoderm perishes and is
absorbed by the growing body of the permanent adult stage. This
deciduous stage of the ichneumon may accordingly be termed the prelarval
stage. Now as we find insects with and without this prelarval stage, and
in the radiates quite different degrees of metamorphoses, the inquiry
arises how far these differences are correlated with, and consequently
dependent upon, the physical surroundings of these animals in the free
swimming condition. Merely to point out the differences in the mode of
development of animals is an interesting matter, and one could do worse
things, but the philosophical naturalist cannot rest here. He must seek
how these differences were brought about.]

[Footnote 25: Leuckart, in his great work, "Die Menschlichen Parasiten,"
p. 700, after the analogy of Hirudo, which develops a primitive streak
late in larval life, ventures to consider the first indications of the
germ of Nemertes in its larval, Pilidium form as a primitive streak. He
also suggests that the development of the later larval forms of the
Echinoderms is the same in kind.

Moreover, nearly twenty years ago (1854) Zaddach, a German naturalist,
contended that the worms are closely allied in their mode of development
to the insects and crustaceans. He compares the mode of development of a
leech (Clepsine) and certain bristle-bearing worms (Sænuris, Lumbricatus
and Uaxes); and we may now from Kowalensky's researches (1871) add the
common earth worm (Lumbricus), in which there is no such metamorphosis
as in the sea Nereids, to that of insects; the mode of formation of the
primitive band in the leeches and earth worms being much like that of
insects. This confirms the view of Leuckart and Ganin, who both seem to
have overlooked Zaddach's remarks. Moreover, the rings of the harder
bodied worms, as Zaddach says, contain chitine, as in the insects.
Zaddach also enters into farther details, which in his opinion ally the
worms nearer to the insects than many naturalists at his time were
disposed to allow. The singular Echinoderes has some remarkable
Arthropod characters.]

[Footnote 26: Vergleichende Anatomie, 2te Auflage, 1870, p. 437. I
should, however, here add that I am told by Mr. Putnam that some fishes
which have no swim-bladder, are surface-swimmers, and _vice versa_.]

[Footnote 27: Reported In "Nature" for Nov. 9, 1871.]

[Footnote 28: The Embryology of Chrysopa, and its bearings on the
Classification of the Neuroptera, "American Naturalist," vol. v. Sept.,
1871.]

[Footnote 29: "It is my opinion that the 'incomplete metamorphosis' of
the Orthoptera is the primitive one, _inherited_ from the original
parents of all insects, and the 'complete metamorphosis' of the
Coleoptera, Diptera, etc., a subsequently acquired one." _Fuer Darwin_,
English Trans., p. 121.]




CHAPTER XIV.

INSECT CALENDAR.


In this calendar I propose to especially notice the injurious insects.
References to the times of their appearance must be necessarily vague,
and apply only, in a very general way, to the Northern States. Insects
appear in Texas about six weeks earlier than in Virginia, in the Middle
States six weeks earlier than in northern New England and the
North-western States, and in New England about six weeks earlier than in
Labrador. The time of the appearance of insects corresponds to the time
of the flowering or leafing out of certain trees and herbs; for
instance, the larvæ of the American Tent caterpillar and of the Canker
worm hatch just as the apple tree begins to leaf out; a little later the
Plant lice appear, to feast on the tender leaves; and when, during the
first week in June, our forests and orchards are fully leafed out, hosts
of insects are marshalled to ravage and devour their foliage.


_The Insects of Early Spring._

In April the gardener should scrape and wash thoroughly all his fruit
trees, so as to rub off the eggs of the bark lice which hatch out early
in May. Many injurious caterpillars and insects of all kinds winter
under loose pieces of bark, or under matting and straw at the base of
the trees. Search should also be made for the eggs of the Canker worm
and the American Tent caterpillar, which last are laid in bunches half
an inch long on the terminal shoots of many of our fruit trees. A little
labor spent in this way will save many dollars' worth of fruit. The
"castings" of the Apple Tree Borer (Saperda bivittata) should be looked
for at the base of the tree, and its ravages be promptly arrested. Its
presence can also be detected, it is said, by the dark appearance of the
bark, where the grub is at work: cut in and pull out the young grub. It
is the best time of the year to catch and kill this pest. Cylindrical
bark borers, which are little round, black, weevil-like beetles, often
causing "fire-blight" in pears, etc., are now flying about fruit trees
to lay their eggs; and many other weevils and boring beetles, especially
the Pea weevil (Bruchus pisi, Fig. 215), the Pine weevil (Pissodes
strobi, Fig. 216), and Hylobius pales and Hylurgus terebrans, also
infesting the pine, now abound, and the collector can obtain many
specimens not met with at other times.

[Illustration: 215. Pea Weevil and Maggot.]

[Illustration: 216 Pine Weevil and Young.]

The housewife must now guard against the intrusion of Clothes moths
(Tinea), while many other species of minute moths (Tineids) and of
Leaf-rollers (Tortricidæ) will be flying about orchards and gardens just
as the buds are beginning to unfold; especially the Coddling moth
(Carpocapsa pomonella). On warm days myriads of these and other insects
may be seen filling the air; it is the busiest time of their lives, as
all are on errands of love to their kind, but of mischief to the
agriculturist.

When the May Flower--"O commendable flowre and most in minde"--blooms,
and the willows hang out their golden catkins, we shall hear the hum of
the wild bee, and the insect hunter will reap a rich harvest of
rarities. Seek now on the abdomen of various wild bees, such as Andrena,
for that most eccentric of all our insects, the Stylops Childreni. The
curious larvæ of the Oil beetle may be found abundantly on the bodies of
various species of Bombus, Andrena and Halictus, with their heads
plunged in between the segments of the bee's body.

[Illustration: 217. The Comma Butterfly.]

[Illustration: 218. Tachina.]

The beautiful moth, Adela, with its immensely long antennæ, may be seen,
with other smaller moths, feeding on the blossoms of the willow. The
Ants wake from their winter's sleep and throw up their hillocks, and the
"thriving pismire" issues from his vaulted galleries constructed in some
decaying log or stump, while the Angle worms emulate late their
six-footed neighbors. During the mild days of March, ere the snow has
melted away--

  "The dandy Butterfly,
  All exquisitely drest,"

will visit our gardens. Such are various kinds of Vanessa and Grapta
(Fig. 217, G. c-argenteum[30]). The beautiful Brephos infans flies
before the snow disappears.

  "The Gnat, old back-bent fellow,
  In frugal frieze coat drest,"

will celebrate the coming of Spring, with his choral dance. Such is
Trichocera hyemalis, which may be seen in multitudes towards twilight on
mild evenings. Many flies are now on the wing, such as Tachina (Fig.
218) and its allies; the four spotted Mosquito, Anopheles
quadrimaculatus, and the delicate species of Chironomus, whose males
have such beautifully feathered antennæ, assemble in swarms. Now is the
time for the collector to turn up stones and sticks by the river's side
and in grassy damp pastures, for Ground beetles (Carabidæ), and to
frequent sunny paths for the gay Cicindela and the Bombylius fly, or
fish in brooks and pools for water beetles and various larvæ of
Neuroptera and Diptera; while many flies and beetles are attracted to
freshly cut maples or birches running with sap; indeed, many insects,
rarely found elsewhere, assemble in quantities about the stumps of these
trees, from which the sap oozes in March and April.

In April the injurious insects in the Northern States have scarcely
begun their work of destruction, as the buds do not unfold before the
first of May. We give an account, however, of some of the beneficial
insects which are now to be found in grass-lands and in gardens. The
farmer should know his true insect friends as well as his insect foes.
We introduce to our readers a large family of ground-beetles (Carabidæ,
from Carabus, the name of the typical genus) which prey on those insects
largely injurious to crops. A study of the figures will familiarize our
readers with the principal forms. They are dark-colored, brown or black,
with metallic hues, and are seen in spring and throughout the summer,
running in grass, or lurking under stones and sticks in damp places,
whence they sally forth to hunt by night, when many vegetable-eating
insects are most active.

[Illustration: 219. Calosoma scrutator.]

[Illustration: 220. Calosoma calidum and Larva.]

The larvæ are found in much the same situations as the mature beetles.
They are, elongate, oblong, and rather broad, the terminal ring of the
body being armed with two horny hooks, and having a single fleshy leg
beneath; and are usually black in color. The larva of Calosoma (C.
calidum, Fig. 220; _a_, the beetle; and Fig. 219, C. scrutator) ascends
trees to feed on caterpillars, such as the Canker worm. When about to
transform to the pupa state, it forms a rude cocoon in the earth. The
beetle lies in wait for its prey in shallow pits excavated in pastures.
We once saw it fiercely attack a May beetle (Lachnosterna fusca) nearly
twice its size; it tore open the hard sides of its clumsy and helpless
victim with tiger-like ferocity. Carabus (Fig. 221, C. serratus Say, and
pupa of Carabus auronitens of Europe, after Westwood) is a closely
allied form, with very similar habits.

[Illustration: 221. Carabus and Pupa.]

[Illustration: 222. Brachinus.]

[Illustration: 223. Casnonia.]

[Illustration: 224. Pangus.]

[Illustration: 225. Agonum.]

[Illustration: 226. Carabid Larva.]

A much smaller form is the curious Bombardier beetle, Brachinus (Fig.
222, B. fumans), with its narrow head and heart-shaped prothorax. It is
remarkable for discharging with quite an explosion from the end of its
body a pungent fluid, probably as a protection against its enemies. An
allied genus is Casnonia (Fig. 223, C. Pensylvanica), which has a long
neck and spotted wing covers. Figure 224, Pangus caliginosus, and figure
225, Agonum cupripenne, represent two common forms. The former is black,
while the latter is a pretty insect, greenish, with purplish-red
wing-covers, and black legs.

Figure 226, enlarged about three times, represents a singular larva
found by Mr. J. H. Emerton under a stone early in spring. Dr. LeConte,
to whom we sent a figure, supposes that it may possibly be a larva of
Harpalus, or Pangus caliginosus. It is evidently a young Carabid. The
under side is represented.


_The Insects of May._

During this month there is great activity among the insects. As the
flowers bloom and the leaves appear, multitudes wake from their long
winter sleep, and during this month pass through the remainder of their
transformations, and prepare for the summer campaign. Most insects
hibernate in the chrysalis or pupa state, while many winter in the
caterpillar or larva state, such as the larvæ of several Noctuidæ and
the "yellow-bear," and other caterpillars of Arctia and its allies.
Other insects hibernate in the adult or imago form, either as beetles,
butterflies or certain species of bees.

It is well known that the Queen Humble bee winters under the moss, or in
her old nest. During the present month her rovings seem to have a more
definite object, and she seeks some deserted mouse's nest, or hollow in
a tree or stump, and there stows away her pellets of pollen, containing
two or three eggs apiece, which, late in the summer, are to form the
nucleus of a well-appointed colony. The Carpenter bees (Ceratina and
Xylocopa, the latter of which is found in abundance south of New
England) are busy in refitting and tunnelling the hollows of the grape;
while the Ceratina hollows out the stem of the elder, or blackberry.
This little upholsterer bee carpets her honey-tight apartment, storing
it with food for her young, and later in the season, in June, several of
these cartridge-like cells, whose silken walls resemble the finest and
most delicate parchment, may be found in the hollow stems of these
plants. The Mason bee (Osmia) places her nest in a more exposed site,
building her earthen cells of pellets of moistened mud, either situated
under a stone, or in some more sheltered place; for instance, in a
deserted oak-gall, ranging half a dozen of them side by side along the
vault of this strange domicile. Meanwhile their more lowly relatives,
the Andrena and Halictus bees, are engaged in tunnelling the side of
some sunny bank or path, running long galleries underground, sometimes
for a foot or more, at the farthest end of which are to be found, in
summer, little earthen urn-like cells, in which the grubs live upon the
pollen stored up for them in little balls of the size of a pea. Later in
the month, the Gall flies (Cynips), those physiological puzzles, sting
the leaves of our oaks of different species, giving rise to the strange
excrescences and manifold deformities which deface the stems and leaves
of our most beautiful forest trees.

[Illustration: 227. Chrysophanus Thoe.[31]] 31 A: The lower side of the
wings is figured on the right side of this and Figs. 228 and 229.

[Illustration: 228. Argynnis Aphrodite.]

[Illustration: 229. Melitæa Phaeton.]

When the Kalmia, Rhodora, and wild cherries are in bloom, many of our
most beautiful butterflies appear; such are the different species of
Chrysophanus (Fig. 227), Lycæna, Thecla and Argynnis (Fig. 228). At this
time we have found the rare larva of Melitæa Phaeton (Fig. 229) clothed
in the richest red and velvety black, feeding daintily upon the hazel
nut, and tender leaves of the golden rod. In June, it changes to the
chrysalis state, and early in July the butterfly rises from the cold,
damp bogs, where we have oftenest found it, clad in its rich dress of
velvety black and red.

Later still, when the lilac blooms, and farther south the broad-leaved
Kalmia, the gaily-colored Humming Bird moth (Sesia) visits the flowers
in company with the Swallow-tail butterfly (Papilio Turnus). At
twilight, the Hawk moth (Sphinx) darts noiselessly through our gardens,
as soon as the honeysuckles, pinks and lilies are in blossom.

[Illustration: 230. D. 12-punctata.]

[Illustration: 231. Diabrotica vittata.]

Among the flies, mosquitoes now appear, though they have not yet,
perhaps, strayed far from their native swamps and fens; and their
mammoth allies, the Daddy-long-legs (Tipula), rise from the fields and
mould of our gardens in great numbers.

[Illustration: Fig. 232. Plum Weevil and Young.]

Of the beetles, those which feed on leaves now become specially active.
The Squash beetle (Diabrotica vittata, Fig. 231, and Fig. 230, D.
12-punctata) now attacks the squash plants before they are fairly up;
and the Plum weevil (Conotrachelus nenuphar, Fig. 232) will sting the
newly formed fruit, late in the month, or early in June. Many other
weevils now abound, stinging the seeds and fruit, and depositing their
eggs just under the skin. So immense are the numbers of insects which
fill the air and enliven the fields and woodlands just as summer comes
in, that a bare enumeration of them would overcrowd our pages, and tire
the reader.

[Illustration: 233. May Fly.]

A word, however, about our water insects. Late in the month the May fly
(Ephemera, Fig. 233) appears, often rising in immense numbers, from the
surface of pools and sluggish brooks. In Europe, whole clouds of these
delicate forms, with their thin white wings, have been known to fall
like snow upon the ground, when the peasants gather them up in heaps to
enrich their gardens and farms.

The Case worms, or Caddis flies (Fig. 234), begin now to leave their
portable houses, formed of pieces of leaves, or sticks and fine gravel,
or even of shells, as in an European species, and fly over the water,
resting on the overhanging trees.

A few busy Mosquito Hawks, or Dragon flies (Libellula), herald the
coming of the summer brood of these indefatigable friends of the
agriculturist. During their whole life below the waters, these
entomological Herods have slain and sucked the blood of myriads of
infant mosquitoes and other insects; and now in their new world above
the waters, with still more intensified powers of doing mischief,
happily, however, to flies mostly obnoxious to man, they riot in
bloodshed and carnage.

[Illustration: 234. Different Forms of Case Worms.]

This is the season to stock the fresh-water aquarium. Go to the nearest
brook, gather a sprig or two of the water cress, which spreads so
rapidly, a root of the eel grass, and plant them in a glass dish or deep
jar. Pour in your water, let the sand and sediment settle, and then put
in a few Tadpoles, a Newt (Salamander), Snails (Limnæa, Planorbis and
Valvata), Caddis flies and Water beetles, together with the gatherings
from a thicket of eel grass, or other submerged plants, being rich in
the young of various flies, Ephemeras, Dragon flies and Water fleas
(Entomostraca, Fig. 235), which last are beautiful objects for the
microscope, and in a few days the occupants will feel at home, and the
aquarium will be swarming with life, affording amusement and occupation
for many a dull hour, by day or at night, in watching the marvels of
insect transformations, and plant-growth.

Among the injurious hymenoptera, which abound late in this month, is
the Rose Saw fly (Selandria rosæ, Fig. 236) and S. cerasi. The eggs are
then laid, and the last of June, or early in July, the slug-like larvæ
mature, and the perfect insects fly in July. Various Gall flies now lay
their eggs in the buds, leaves and stems of various kinds of oaks,
blackberries, blueberries and other plants.

[Illustration: 235. Water Flea.]

[Illustration: 236. Selandria rosæ.]

Dipterous Gall flies are now laying their eggs in cereals. The Hessian
fly (Cecidomyia destructor) has two broods, the fly appearing both in
spring and autumn. The fly lays twenty or thirty eggs in a crease in the
leaf of the young plant. In about four days, in warm weather, they
hatch, and the pale-red larvæ crawl down the leaf, working their way in
between it and the main stalk, passing downward till they come to a
joint, just above which they remain, a little below the surface of the
ground, with the head towards the root of the plant. Here they imbibe
the sap by suction alone, and, by the simple pressure of their bodies
become imbedded in the side of the stem. Two or three larvæ thus
imbedded serve to weaken the plant and cause it to wither and die. The
second brood of larvæ remains through the winter in the flax-seed, or
puparium. By turning the stubble with the plough in the autumn and early
spring, its imago may be destroyed, and thus its ravages may be checked.
(Figure 237 represents the female, which is about one-third as large as
a mosquito: _a_, the larva; _b_, the pupa; and _c_ represents the joint
near the ground where the maggots live.) The same may be said of the
Wheat midge (Cecidomyia tritici), which attacks the wheat in the ear,
and which transforms an inch deep beneath the surface.

[Illustration: 237. Hessian Fly.]

[Illustration: 238. Turnip Butterfly.]

Among the butterflies which appear this month are the Turnip butterfly
(Pontia oleracea, Fig. 238,) which lays its eggs the last of the month.
The eggs hatch in a week or ten days, and in about two weeks the larva
changes to a chrysalis. Thanaos junevalis and T. Brizo fly late in May.
The caterpillars live on the pea and other papilionaceous plants. Thecla
Auburniana, T. Niphon, and other species fly in dry, sunny fields, some
in April. Argynnis Myrina flies from the last of May through June, and a
second brood appears in August and September. Vanessa J-album and V.
interrogationis appear in May, and again in August and September. The
caterpillars of the latter species live on the elm, lime and hop-vine.
Grapta comma also feeds on the hop. Alypia 8-maculata (Fig. 49) flies at
this time, and in August its larva feeds on the grape. Sphinx gordius,
S. 5-maculata (Fig. 239) and other Sphinges and Sesia (the Clear-winged
moth), appear the last of May. Arctia Arge, A. virgo, A. phalerata and
other species fly from the last of May through the summer. Hyphantria
textor, the Fall-weaver, is found in May or June. The moth of the
Salt-marsh caterpillar appears at this time, and various Cut worms
(Agrotis, Fig. 240) abound, hiding in the daytime under stones and
sticks, etc., while various Tineids and Tortrices, or Leaf-rolling
caterpillars, begin to devour tender leaves and buds and opening
blossoms of flowers and fruit trees.

[Illustration: 239. Sphinx 5-maculata, Larva and Pupa.]

[Illustration: 240. Cut Worm and Moth.]

The White-pine weevil flies about in warm days. We have found its
burrows winding irregularly over the inner surface of the bark and
leading into the sap-wood. Each cell, in which it hibernates, in the
middle of March, contains the yellowish white footless grub. Early in
April it changes to a pupa, and a month after the beetle appears, and in
a few days deposits its egg under the bark of old pine trees. It also
oviposits in the terminal shoots of pine saplings, dwarfing and
permanently deforming the tree. Associated with this weevil we have
found the smaller, rounder, more cylindrical, whitish grubs of the
Hylurgus terebrans, which mines the inner layers of the bark, slightly
grooving the sap-wood. Later in April it pupates, and its habits accord
in general with those of Pissodes strobi. Another Pine weevil also
abounds at this time, as well as Otiorhynchus picipes (Fig. 241), which
injures beans, etc.

[Illustration: 241. Garden Weevil.]

Cylindrical bark-borers, which are little, round, weevil-like beetles,
are now flying about fruit trees, to lay their eggs in the bark.
Associated with the Pissodes, we may find in April the galleries of
Tomicus pini, branching out from a common centre. They are filled up
with fine sawdust, and, according to Dr. Fitch, are notched in the sides
"in which the eggs have been placed, where they would remain undisturbed
by the beetle as it crawled backwards and forth through the gallery."
These little beetles have not the long snouts of the weevils, hence they
cannot bore through the outer bark, but enter into the burrows made the
preceding year, and distribute the eggs along the sides (Fitch). Another
Tomicus, more dangerous than the preceding, feeds exclusively in the
sap-wood, running solitary galleries for a distance of two inches
towards the centre of the tree. We figure Tomicus xylographus Say (Fig.
242, enlarged). It is the most formidable enemy to the white pine in the
North, and the yellow pine in the South that we have. It also flies in
May. Ptinus fur (Fig. 243, much enlarged) is now found in out-houses,
and is destructive to cloth, furs, etc., resembling the Larder-beetle
(Dermestes) in its habits. It is fourteen hundredths of an inch in
length.

[Illustration: 242. Pine Weevil.]

[Illustration: 243. Ptinus and Larva.]


_The Insects of June._

Early in the month the Parsnip butterfly (Papilio Asterias) may be seen
flying about, preparatory to laying its eggs for the brood of
caterpillars which appear in August. At the time of the flowering of the
raspberry and blackberry, the young larva of Vanessa Antiopa, one of our
most abundant butterflies, may be found living socially on the leaves of
the willow; while the mature larva of another much smaller butterfly,
the little Copper skipper (Chrysophanus Americans), so abundant at this
time, may sometimes be found on the clover. It is a short, oval,
greenish worm, with very short legs. The dun-colored skippers (Hesperia)
abound towards the middle of the month, darting over the flowers of the
blueberry and blackberry, in sunny openings in the forests.

The family of Hawk moths (Sphinges) now appear in greater abundance,
hovering at twilight over flower-beds, and, during this time, deposit
their eggs on the leaves of various fruit-trees. The American Tent
caterpillar makes its cocoon, and assumes the pupa state. The
caterpillar passes several days within the cocoon, in what may be
called the semi-pupa states during which period the chrysalis skin is
forming beneath the contracted and loosened larva skin. We once
experimented on a larva which had just completed its cocoon, to learn
how much silk it could produce. On removing its cocoon it made another
of the same thickness; but on destroying this second one it spun a third
but frail web, scarcely concealing its form. A minute Ichneumon
parasite, allied to Platygaster, lays its eggs within those of this
moth, as we once detected one under a bunch of eggs, and afterwards
reared a few from the same lot of eggs. A still more minute egg-parasite
(Fig. 244) we have seen ovipositing in the early spring, in the eggs of
the Canker-worm.

[Illustration: 244. Canker worm Egg-parasite.]

Among that beautiful family of moths, the Phalænidæ, comprising the
Geometers, Loopers, or Span-worms, are two formidable foes to fruit
growers. The habits of the Canker worm should be well known. With proper
care and well-directed energy, we believe their attacks can be in a
great measure prevented. The English sparrow, doves and other
insectivorous birds, if there are any others that eat them, should be
domesticated in order to reduce the number of these pests. More care
than has yet been taken should be devoted to destroying the eggs laid in
the autumn, and also the wingless females, as they crawl up the trees in
the spring and autumn to lay their eggs. The evil is usually done before
the farmer is well aware that the calamity has fallen upon him. As soon
as, and even before the trees have fairly leafed out, they should be
visited morning, noon and night, shaken and thoroughly examined and
cleared of the caterpillars. By well-concerted action among
agriculturists, who should form a Board of Destruction, numbering every
man, woman and child on the farm, this fearful scourge may be abated by
the simplest means, as the cholera or any epidemic disease can in a
great measure be averted by taking proper sanitary precautions. The
Canker worms hatch out during the early part of May, from eggs laid in
the fall and spring, on the branches of various fruit-trees. Just as the
buds unfold, the young caterpillars make little holes through the tender
leaves, eating the pulpy portions, not touching the veins and midribs.
When four weeks old they creep to the ground, or let themselves down by
spinning a silken thread, and burrow from two to six inches in the soil,
where they change to chrysalids in a day or two, and in this state live
till late in the fall, or until the early spring, when they assume the
imago or moth form. The sexes then unite, and the eggs are deposited for
the next generation.

The Canker worm is widely distributed, though its ravages used to be
confined mostly to the immediate vicinity of Boston. We have seen
specimens of the moth from Illinois. Riley has found it in Missouri.

[Illustration: 245. Abraxas ribearia.]

The Abraxas ribearia of Fitch (Fig. 245, moth), the well-known Currant
worm, defoliates whole rows of currant bushes. This pretty caterpillar
may be easily known by its body being of a deep golden color, spotted
with black. The bushes should be visited morning, noon and night, and
thoroughly shaken (killing the caterpillars) and sprinkled with ashes.

[Illustration: 246. May Beetle and Young.]

Among multitudes of beetles (Coleoptera) injurious to the crops, are the
May beetle (Lachnosterna fusca, Fig. 246), whose larva, a large white
grub, is injurious to the roots of grass and to strawberry vines. The
Rose beetle appears about the time of the blossoming of the rose. The
Fire-flies now show their light during mild evenings, and on hot sultry
days the shrill rasping song of the male Cicada, for "they all have
voiceless wives," cuts the air: The Chinch-bug, that fell destroyer of
our wheat crops, appears, according to Harris, in the middle of the
month, and "may be seen in their various stages of growth on all kinds
of grain, on corn and herds-grass during the whole summer." So widely
spread is this insect at present, that we have even detected it in
August on the summit of Mount Washington.

[Illustration: 247. Pemphigus.]

The Diptera, or two-winged flies, contain hosts of noxious insects, such
as the various Cecidomyians, or two-winged Gall flies, which now sting
the culms of the wheat and grasses, and various grains, and leaves of
trees, producing gall-like excrescences of varying form. Legions of
these delicate minute flies fill the air at twilight, hovering over
wheat fields and shrubbery. A strong north west wind, at such times, is
of incalculable value to the farmer. Moreover, minute flies, allied to
the house fly, such as Tephritis, Oscinis, etc., now attack the young
cereals, doing immense injury to grain.

[Illustration: 248. Apple Bark Louse.]

Millions of Aphides, or Plant lice, now infest our shade and fruit
trees, crowding every green leaf, into which they insert their tiny
beaks, sucking in the sap, causing the leaves to curl up and wither.
They also attack the stems and even the roots of plants, though these
latter (Pemphigus, Fig. 247) differ generically from the true Plant
lice. Fruit trees should be again washed and rubbed to kill off the
young Bark lice, of which the common apple Bark louse (Aspidiotus
conchiformis, Fig. 248), whose oyster-shaped scales may be found in
myriads on neglected trees, is a too familiar example. Another pest of
apple trees is the woolly Blight (Eriosoma lanigera). These insects
secrete from the surface of the body a downy, cottony substance which
conceals the animal, and when they are, as usual, grouped together on
the trees, makes them look like patches of mould. The natural insect
enemies of the Plant lice now abound; such are the Lady bugs
(Coccinella, Fig. 249); the larva of the Syrphus fly (Fig. 76), which
devours immense quantities, and the larva of the Golden-eyed,
Lace-winged fly (Chrysopa, Fig. 256).

[Illustration: 249. Coccinella and Young.]

The last days of June are literally the heyday and jubilee of insect
life. The entomological world holds high carnival, though in this
country they are, perhaps, more given to mass-meetings and caucuses. The
earth, the air, and the water teem with insect life. The insects of
mid-summer, now appear. Among the butterflies, the Wood Satyrus
(Neonympha Eurythris) skips in its low flight through the pines. The
larva of Grapta Progne appears on the currants, and feeds beneath the
leaves on hot sunny days. The larva of Cynthia cardui may be found on
the hollyhocks; the pupa state lasts twelve days, the butterfly
appearing in the middle or last of July. The Hyphantria textor now lays
its smooth, spherical eggs in broad patches on the under side of the
leaves of the apple, which the caterpillar will ravage in August; and
its ally, the Halesidota caryæ, we have found ovipositing the last week
in the month on the leaves of the butternut. The Squash bug, Coreus
(Gonocerus) tristis (Fig. 250) is now very abundant, gathering about the
roots of the squash vines, often in immense numbers, blackening the
stems with their dark, blackish-brown bodies. This insect is easily
distinguished from the yellow striped Squash beetle previously
mentioned, by its much greater size, and its entirely different
structure and habits. It is a true bug (Hemipter, of which the bed-bug
is an example), piercing the leaves and stalks, and drawing out the sap
with its long sucker.

[Illustration: 250. Squash Bug.]

In June, also, we have found that beautiful butterfly, Militæa Phaeton
rising from the low, cold swamps. Its larva transforms early in June or
the last week in May, into a beautiful chrysalis. The larva hibernates
through the winter, and may be found early in spring feeding on the
leaves of the aster, the Viburnum dentatum and hazel. It is black and
deep orange-red, with long, thick-set, black spines.

The Currant borer, Trochilium tipuliforme (Fig. 251), a beautiful,
slender, agile, deep blue moth, with transparent wings, flies the last
of the month about currant bushes, and its chrysalids may be found in
May in the stems. Among moths, that of the American Tent caterpillar
flies during the last of June and July, and its white cocoons can be
detected under bark, and in sheltered parts of fences and out-houses.

Among others of the interesting group of Silk worms (Bombycidæ) are
Lithosa, Crocota and allies, which fly in the daytime, and the different
species of Arctia, and the white Arctians, Spilosoma, and Leucarctia,
the parent of the Salt-marsh Caterpillar.

[Illustration: 251. Currant Moth.]

Many Leaf rollers, Tortrices, are rolling up leaves in various ways for
their habitations, and to conceal them from too prying birds; and hosts
of young Tineans are now mining leaves, and excavating the interior of
seeds and various fruits. Grape-growers should guard against the attacks
of a species of Tortrix (Penthina vitivorana) which rolls the leaves of
the grape, and, according to Mr. M. C. Reed, of Hudson, Ohio, "in
mid-summer deposits its eggs in the grape; a single egg in a grape. Its
presence is soon indicated by a reddish color on that side of the yet
green grape, and on opening it, the winding channel opened by the larva
in the pulp is seen, and the minute worm, which is white, with a dark
head, is found at the end of the channel. It continues to feed upon the
pulp of the fruit, and when it reaches the seeds, eats out their
interior; and if the supply from one grape is extinguished before its
growth is completed, it fastens this to an adjoining grape with a web,
and burrows into it. It finally grows to about one-half of an inch in
length, becomes brown, almost black, the head retaining its cinnamon
color. When it leaves the grape it is very active, and has the power of
letting itself down by a thread of silk. All my efforts to obtain the
cocoons failed until I placed fresh grape leaves in the jar containing
the grapes. The larvæ immediately betook themselves to these, and,
cutting a curved line through the leaf thus), sometimes two lines thus
(), folded the edge or edges over, and in the fold assumed the chrysalis
form. From specimens saved, I shall hope to obtain the perfect insect
this season, and perhaps obtain information which will aid in checking
its increase. Already it is so abundant that it is necessary to examine
every branch of ripe grapes, and clip out the infested berries before
sending them to the table. A rapid increase in its numbers would
interfere seriously with the cultivation of the grape in this locality."

The Rose beetle (Macrodactyla subspinosa) appears in great abundance.
The various species of Buprestis are abundant; among them are the
Peach-borer (Dicerca divaricata), which may be now found flying about
peach and cherry trees; and Chrysobothris fulvogutta, and C. Harrisii,
about white pines. A large weevil (Arrhenodes septentrionalis), which
lives under the bark of the white oak, appears in June and July. The
Chinch bug begins its terrible ravages in the wheat fields. The various
species of Chrysopa or Lace-winged flies, appear during this month.


_The Insects of July._

During mid-summer the bees and wasps are very busy building their nests
and rearing their young. The Humble bees, late in June and the first of
this month, send out their first broods of workers, and about the middle
of the month the second lot of eggs are laid, which produce the
smaller-sized females and males, while eggs laid late in the month and
early in August, produce the larger-sized queens, which soon hatch.
These hibernate. The habits of their peculiar parasite, Apathus, an
insect which closely resembles the Humble bee, are still unknown.

[Illustration: 252. White-faced Wasp.]

The Leaf-cutter bee (Megachile) may be seen flying about with pieces of
rose-leaf, with which she builds, for a period of twenty days, her
cells, often thirty in number, using for this purpose, according to Mr.
F. W. Putnam's estimate,[32] at least one thousand pieces! The bees
referred to "worked so diligently that they ruined five or six
rose-bushes, not leaving a single unblighted leaf uncut, and were then
forced to take the leaves of a locust tree as a substitute."

The Paper-making wasps, of which Vespa maculata (Fig. 252), the
"White-faced wasp," is our largest species, are now completing their
nests, and feeding their young with flies. The Solitary wasp (Odynerus
albophaleratus) fills its earthen cells with minute caterpillars, which
it paralyzes with its poisonous sting. A group of mud-cells, each stored
with food for the single larva within, we once found concealed in a
deserted nest of the American Tent caterpillar. Numerous species of Wood
wasps (Crabronidæ) are engaged in tunnelling the stems of the
blackberry, the elder, and syringa, and enlarging and refitting old nail
holes, and burrowing in rotten wood, storing their cells with flies,
caterpillars, aphides and spiders, according to the habit of each
species. Eumenes fraterna, which attaches its single, large, thin-walled
cell of mud to the stems of plants, is, according to Dr. T. W. Harris,
known to store it with Canker worms. Pelopæus, the Mud-dauber, is now
building its earthen cells, plastering them on old rafters and stone
walls.

The Saw flies (Tenthredo), etc., abound in our gardens this month. The
Selandria vitis attacks the vine, while Selandria rosæ, the Rose slug,
injures the rose. The disgusting Pear slug-worm (S. cerasi), often live
twenty to thirty on a leaf, eating the parenchyma, or softer tissues,
leaving the blighted leaf. The leaves should be sprinkled with a mixture
of whale-oil soap and water, in the proportion of two pounds of soap to
fifteen gallons of water.

[Illustration: 253. Imported Cabbage Butterfly.]

Among the butterflies, Melitæa Ismeria, in the south, and M. Harrisii,
in the north, are sometimes seen. A second brood of Colias Philodice,
the common sulphur-yellow butterfly, appears, and Pieris oleracea visits
turnip-patches. It lays its eggs in June on the leaves, and the
full-grown, dark-green, hairy larva may be found in August. The Pieria
rapæ, or imported cabbage butterfly (Fig. 253, male) is now also
abundant. Its green hairy larva is fearfully prevalent about Boston and
New York. The last of the month a new brood of Grapta comma appears, and
a second brood of the larva of Chrysophanus Americanus may be found on
the sorrel.

The larvæ of Pyrrarctia Isabella hatch out the first week in July, and
the snuff-colored moth enters our windows at night, in company with a
host of night-flying moths. These large moths, many of which are
injurious to crops, are commonly thought to feed on clothes and carpets.
The true carpet and clothes moths are minute species, which flutter
noiselessly about our apartments. Their narrow, feathery wings are edged
with long silken fringes, and almost the slightest touch kills them.

[Illustration: 254. Apple Borer, Larva and Pupa.]

[Illustration: 255. Lady Bug and Pupa.]

Among beetles, the various borers, such as the Saperda, or apple tree
borer (Fig. 254) are now pairing, and fly in the hot sun about trees.
Nearly each tree has its peculiar enemy, which drives its galleries into
the trunk and branches of the tree. Among the Tiger beetles, frequenting
sandy places, the large Cicindela generosa and the Cicindela hirticollis
are most common. The grotesque larvæ live in deep holes in sand-banks.

[Illustration: 256. Lace-winged Fly and Eggs.]

[Illustration: 257. Forceps-tail.]

The nine-spotted Lady Bug, Coccinella novemnotata (Fig. 255, with pupa)
is one of a large group of beetles, most beneficial from their habit of
feeding on the plant lice. We figure another enemy of the Aphides,
Chrysopa, and its eggs (Fig. 256), mounted each on a long silken stalk,
thus placed above the reach of harm.

Among other beneficial insects belonging to the Neuroptera, is the
immense family of Libellulidæ, or Dragon flies. The Forceps-tail, or
Panorpa, P. rufescens (Fig. 257), is found in bushy fields and
shrubbery. They prey on smaller insects, and the males are armed at the
extremity of the body with an enormous forceps-like apparatus.


_The Insects of August._

During this month great multitudes of bugs (Hemiptera) are found in our
fields and gardens; and to this group of insects the present chapter
will be devoted. They are nearly all injurious to crops, as they live on
the sap of plants, stinging them with their long suckers. Their
continued attacks cause the leaves to wither and blight.

The grain Aphis, in certain years, desolates our wheat fields. We have
seen the heads black with these terrible pests. They pierce the grain,
extract the sap, causing it to shrink and lose the greater part of its
bulk. It is a most insidious and difficult foe to overcome.

[Illustration: 258. Leaf-hopper of the Vine.]

The various leaf-hoppers, Tettigonia (Fig. 258) and Ceresa, abound on
the leaves of plants, sadly blighting them; and the Tettigonias frequent
damp, wet, swampy places. A very abundant species on grass produces what
is called "frog's spittle." It can easily be traced through all its
changes by frequently examining the mass of froth which surrounds it.
Tettigonia Vitis blights the leaf of the grape-vine. It is a tenth of an
inch long, and is straw-yellow, striped with red. Tettigonia rosæ, a
still smaller species, infests the rose, often to an alarming extent.

The Notonecta, or water boatman, is much like a Tettigonia, but its
wings are transparent on the outer half, and its legs are fringed with
long hairs, being formed for swimming. It rows over the surface in
pursuit of insects. Notonecta undulata Say (Fig. 259) is a common form
in New England.

Another insect hunter is the singular Ranatra fusca (Fig. 260). It is
light brown in color, with a long respiratory tube which it raises above
the surface of the water when it wishes to breathe. This species
connects the Water-boatman with the Water-skaters, or Gerris, a familiar
insect, of which Gerris paludum (Fig. 261) is commonly seen running over
the surface of streams and pools.

[Illustration: 259. Notonecta.]

[Illustration: 260. Ranatra.]

[Illustration: 261. Water Skater.]

[Illustration: 262. Pirates.]

Reduvius and its allies belong to a large family of very useful insects,
as they prey largely on caterpillars and noxious insects. Such is
Pirates picipes (Fig. 262), a common species. It is an ally of Reduvius
personates, a valued friend to man, as in Europe it destroys the
bed-bug. Its specific name is derived from its habit while immature, of
concealing itself in a case of dust, the better to approach its prey.

[Illustration: 263. Phymata.]

Another friend of the agriculturist is the Phymata erosa (Fig. 263). Mr.
F. G. Sanborn states that "these insects have been taken in great
numbers upon the linden trees in the city of Boston, and were seen in
the act of devouring the Aphides, which have infested the shade trees of
that city for several years past. They are described by a gentleman who
watched their operations with great interest, as 'stealing up to a
louse, coolly seizing and tucking it under the arm, then inserting the
beak and sucking it dry.' They are supposed to feed also on other
vegetable-eating insects as well as the plant louse."

Phytocoris lineolaris swarms in our gardens during this month. It is
described and figured in "Harris's Treatise on Insects." Closely allied,
though generally wingless, is that enemy of our peace, the bed-bug. It
has a small somewhat triangular head, orbicular thorax, and large,
round, flattened abdomen. It is generally wingless, having only two
small wing-pads instead. The eggs are oval, white; the young escape by
pushing off a lid at one end of the shell. They are white, transparent,
differing from the perfect insect in having a broad, triangular head,
and short, thick antennæ. Indeed, this is the general form of lice
(Pediculus Vestimenti, and P. capitis), to which the larva of Cimex has
the closest affinity. Some Cimices are parasites, infesting pigeons,
swallows, etc., in this way also showing their near relation to lice.
Besides the Reduvius, the cockroach is the natural enemy of the bed-bug,
and destroys large numbers. Houses have been cleared of bugs after being
thoroughly fumigated with brimstone.

During this month the ravages of grasshoppers are, in the West, very
wide-spread. We have received from Major F. Hawn, of Leavenworth,
Kansas, a most interesting account of the Red-legged locust (Caloptenus
femur-rubrum). "They commence depositing their eggs in the latter part
of August. They are fusiform, slightly gibbous, and of a buff-color.
They are placed about three-fourths of an inch beneath the surface, in a
compact mass around a vertical axis, pointing obliquely up and outwards,
and are partially cemented together, the whole presenting a cylindrical
structure, not unlike a small cartridge. They commence hatching in
March, but it requires a range of temperature above 60º F. to bring them
to maturity, and under such conditions they become fledged in
thirty-three days, and in from three to five days after they enter upon
their migratory flight.

"Their instincts are very strong. When food becomes scarce at one point,
a portion of them migrate to new localities, and this movement takes
place simultaneously over large areas. In their progress they stop at no
obstacle they can surmount. In these excursions they often meet with
other trains from an opposite direction, when both join in one.

"The insects are voracious, but discriminating in their choice of food,
yet I know of no plant they reject if pressed by hunger; not even the
foliage of shrubs and trees, including pine and cedar."

[Illustration: 264. Seventeen Year Locust, Eggs and Pupa.]

During this month the Seventeen-year locust (Cicada septendecim of
Linnæus, Fig. 264) has disappeared, and only a few Harvest flies, as the
two other species we have are called, raise their shrill cry during the
dog-days. But as certain years are marked by the appearance of vast
swarms in the Middle States, we cannot do better than to give a brief
summary of its history, which we condense in part from Dr. Harris' work.

The Seventeen-year locust ranges from South-eastern and Western
Massachusetts to Louisiana. Of its distribution west of the Mississippi
Valley, we have no accurate knowledge. In Southern Massachusetts, they
appear in oak forests about the middle of June. After pairing, the
female, by means of her powerful ovipositor, bores a hole obliquely to
the pith, and lays therein from ten to twenty slender white eggs, which
are arranged in pairs, somewhat like the grains on an ear of wheat, and
implanted in the limb. She thus oviposits several times in a twig, and
passes from one to another, until she has laid four or five hundred
eggs. After this she soon dies. The eggs hatch in about two weeks,
though some observers state that they do not hatch for from forty to
over fifty days after being laid. The active grubs are provided with
three pairs of legs. After leaving the egg they fall to the ground,
burrow into it, and seek the roots of plants whose juices they suck by
means of their long beaks. They sometimes attack the roots of fruit
trees, such as the pear and apple. They live nearly seventeen years in
the larva state, and then in the spring change to the pupa, which
chiefly differs from the larva by having rudimentary wings. The damage
done by the larvæ and pupæ, then, consists in their sucking the sap from
the roots of forest, and occasionally fruit trees.

Regarding its appearance, Mr. L. B. Case writes us (June 15) from
Richmond, Indiana: "Just now we are having a tremendous quantity of
locusts in our forests and adjoining fields, and people are greatly
alarmed about them; some say they are Egyptian locusts, etc. This
morning they made a noise, in the woods about half a mile east of us,
very much like the continuous sound of frogs in the early spring, or
just before a storm at evening. It lasted from early in the morning
until evening." Mr. V. T. Chambers writes us that it is abounding in the
vicinity of Covington, Kentucky, "in common with a large portion of the
Western country." He points out some variations in color from those
described by Dr. Fitch, from New York, and states that those occurring
in Kentucky are smaller than those of which the measurements are given
by Dr. Fitch, and states that "these differences indicate that the
groups, appearing in different parts of the country at intervals of
seventeen years, are of different varieties." A careful comparison of
large numbers collected from different broods, in different localities,
and different years, would alone give the facts to decide this
interesting point. Mr. Riley has shown that in the Southern States a
variety appears every thirteen years.

Regarding the question raised by Mr. Chambers, whether the sting of this
insect is poisonous, and which he is inclined to believe to be in part
true, we might say that naturalists generally believe it to be harmless.
No hemiptera are known to be poisonous, that is, to have a poison-gland
connected with the sting, like that of the bee, and careful dissections
by the eminent French naturalist, Lacaze-Duthiers, of three European
species of Cicada, have not revealed any poison apparatus at the base of
the sting. Another proof that it does not pour poison into the wound
made by the ovipositor is, that the twig thus pierced and wounded does
not swell, as in the case of plants wounded by Gall flies, which,
perhaps, secrete an irritating poison, giving rise to tumors of various
shapes. Many insects sting without poisoning the wound; the bite of the
mosquito, black fly, flea, the bed bug, and other hemipterous insects,
are simply punctured wounds, the saliva introduced being slightly
irritant, and to a perfectly healthy constitution they are not
poisonous, though they may grievously afflict some persons, causing the
adjacent parts to swell, and in some weak constitutions induce severe
sickness. Regarding this point, Mr. Chambers writes: "I have heard--not
through the papers--within a few days past of a child, within some
twenty miles of this place, dying from the sting of a Cicada, but have
not had an opportunity to inquire into the truth of the story, but the
following you may rely on. A negro woman in the employment of A. V.
Winston, Esq., at Burlington, Boone County, Ky., fifteen miles distant
from here, went barefooted into his garden a few days since, and while
there was stung or bitten in the foot by a Cicada. The foot immediately
swelled to huge proportions, but by various applications the
inflammation was allayed, and the woman recovered. Mr. Winston, who
relates this, stands as high for intelligence and veracity as any one in
this vicinity. I thought, on first hearing the story, that probably the
sting was by some other insect, but Mr. Winston says that he saw the
Cicada. But perhaps this proves that the sting is _not_ fatal; that
depends on the subject. Some persons suffer terribly from the bite of a
mosquito, while others scarcely feel them. The cuticle of a negro's foot
is nearly impenetrable, and perhaps the sting would have been more
dangerous in a more tender part." It is not improbable that the sting
was made by a wasp (Stizus) which preys on the Cicada. Dr. Le Baron and
Mr Riley believe the wound to be made by the beak, which is the more
probable solution of the problem.

A word more about the Seventeen-year Cicada. Professor Orton writes us
from Yellow Springs, Ohio, that this insect has done great damage to the
apple, peach, and quince trees, and is shortening the fruit crop very
materially. By boring into twigs bearing fruit, the branches break and
the fruit goes with them. "Many orchards have lost full two years'
growth. Though the plum and cherry trees seemed exempt, they attacked
the grape, blackberry, raspberry, elm (white and slippery), maple, white
ash, willow, catalpa, honey-locust and wild rose. We have traces of the
Cicada this year from Columbus, Ohio, to St. Louis. Washington and
Philadelphia have also had a visitation."

[Illustration: 265. Hop Vine Moth and Young.]

[Illustration: 266. Humble Bee Parasite.]

We figure the Hop-vine moth and the larva (Fig. 265) which abound on
hops the last of summer. Also, the Ilythia colonella (Fig. 266, a,
pupa), known in England to be a parasite of the Humble bee. We have
frequently met with it here, though not in Humble bees' nests. The larvæ
feed directly upon the young bees, according to Curtis (Farm Insects).
The Spindle-worm moth (Gortyna zeæ), whose caterpillar lives in the
stalks of Indian corn, and also in dahlias, flies this month. The
withering of the leaves when the corn is young, shows the presence of
this pest. The beetles of various cylindrical Bark borers and Blight
beetles (Tomicus and Scolytus) appear again this month. During this
month the Tree cricket (Oecanthus niveus, Fig. 267) lays its eggs in
the branches of peach trees. It will also eat tobacco leaves.

[Illustration: 267. Tree Cricket.]

We figure (268) the moth of Ennomos subsignaria, the larva of which is
so injurious to shade trees in New York City. It is a widely diffused
species, occurring probably throughout the Northern States. We have
taken the moth in Northern Maine. We have received from Mr. W. V.
Andrews the supposed larvæ of this moth. They are "loopers," that is,
they walk with a looping gait, as if measuring off the ground they walk
over, whence the name "Geometers," more usually applied to them. They
are rather stout, brown, and roughened like a twig of the tree they
inhabit, with an unusually large rust-red head, and red prop-legs, while
the tip of the body is also red. They are a little over an inch long.

[Illustration: 268. Ennomos subsignaria.]


_The Insects of September._

Few new insects make their first appearance for the season during this
month. Most of the species which abound in the early part of the month
are the August forms, which live until they are killed by the frosts
late in the month. From this cause there is towards the end of the month
a very sensible diminution of the number of insects.

The early frosts warn these delicate creatures of approaching cold.
Hence the whole insect population is busied late in the month in looking
out snug winter quarters, or providing for the continuance of the
species. Warned by the cool and frosty nights, multitudes of
caterpillars prepare to spin their dense silken cocoons, which guard
them against frost and cold. Such are the "Spinners," as the Germans
call them, the Silk moths, of which the American Silk worm is a fair
example. The last of September it spins its dense cocoon, in which it
hibernates in the chrysalis state.

The larvæ of those moths, such as the Sphinges, or Hawk moths, which
spin no cocoon, descend deep into the earth, where they transform into
chrysalids and lie in deep earthen cocoons.

The wild bees may now be found frequenting flowers in considerable
numbers. Both sexes of the Humble bee, the Leaf-cutter bee, and other
smaller genera abound during the warm days.

One's attention during an unusually warm and pleasant day in this month
is attracted by clouds of insects filling the air, especially towards
sunset, when the slanting rays of the sun shine through the winged
hosts. On careful investigation these insects will prove to be nearly
all ants, and, perhaps, to belong to a single species. Looking about on
the ground, an unusual activity will be noticed in the ant-hills. This
is the swarming of the ants. The autumnal brood of females has appeared,
and this is their marriage day.

The history of a _formicarium_, or ant's nest, is as follows: The
workers, only, hibernate, and are found early in the spring, taking care
of the eggs and larvæ produced by the autumnal brood of females. In the
course of the summer these eggs and larvaæ arrive at maturity, and swarm
on a hot sultry day, usually early in September. The females, after
their marriage flight, for the small diminutive males seek their company
at this time, descend and enter the ground to lay their eggs for new
colonies, or, as Westwood states, they are often seized by the workers
and retained in the old colonies. Having no more inclination to fly,
they pluck off their wings and may be seen running about wingless.

Dr. C. C. Abbot gives us the following account of the swarming of a
species in New Jersey: "On the afternoon of Oct. 6th, at about 4 P. M.,
we were attracted to a part of the large yard surrounding our home, by a
multitude of large sized insects that filled the air, and appeared to
be of some unusual form of insect life, judging of them from a distance.
On closer inspection these creatures proved to be a brood of red ants
(Formica) that had just emerged from their underground home and were now
for the first time using their delicate wings. The sky, at the time, was
wholly overcast; the wind strong, southeast; thermometer 66º Fahr.
Taking a favorable position near the mass, as they slowly crawled from
the ground, up the blades of grass and stems of clover and small weeds,
we noted, first, that they seemed dazed, without any method in their
movements, save an ill-defined impression that they must go somewhere.
Again, they were pushed forward, usually by those coming after them,
which seemed to add to their confusion. As a brood or colony of insects,
their every movement indicated that they were wholly ill at ease.

"Once at the end of a blade of grass, they seemed even more puzzled as
to what to do. If not followed by a fellow ant, as was usually the case,
they would invariably fall down again to the earth, and sometimes repeat
this movement until a new comer joined in the ascent, when the
_uncertain_ individual would be forced to use his wings. This flight
would be inaugurated by a very rapid buzzing of the wings, as though to
dry them, or prove their owner's power over them, but which it is
difficult to say. After a short rest, the violent movement of the wings
would recommence, and finally losing fear, as it were, the ant would let
go his hold upon the blade of grass and rise slowly upwards. It could,
in fact, scarcely be called flight. The steady vibration of the wings
simply bore them upwards, ten, twenty or thirty feet, until they were
caught by a breeze, or by the steadier wind that was moving at an
elevation equal to the height of the surrounding pine and spruce trees.
So far as we were able to discover, their wings were of the same use to
them, in transporting them from their former home, that the 'wings' of
many seeds are, in scattering them; both are wholly at the mercy of the
winds.

"Mr. Bates, in describing the habits of the Saüba ants (Oecodoma
cephalotes) says,[33] 'The successful _début_ of the winged males and
females depends likewise on the workers. It is amusing to see the
activity and excitement which reign in an ant's nest when the exodus of
the winged individuals is taking place. The workers clear the roads of
exit, and show the most lively interest in their departure, although it
is highly improbable that any of them will return to the same colony.
The swarming or exodus of the winged males and females of the Saüba ant
takes place in January and February, that is, at the commencement of the
rainy season. They come out in the evening in vast numbers, causing
quite a commotion in the streets and lanes.' We have quoted this passage
from Mr. Bates' fascinating book, because of the great similarity and
dissimilarity in the movements of the two species at this period of
their existence. Remembering, at the time the above remarks concerning
the South American species, we looked carefully for the workers, in this
instance, and failed to discover above half a dozen wingless ants above
ground, and these were plodding about, very indifferent, as it appeared
to us, to the fate or welfare of their winged brothers. And on digging
down a few inches, we could find but comparatively few individuals in
the nest, and could detect no movements on their parts that referred to
the exodus of winged individuals, then going on.

"On the other hand, the time of day agrees with the remarks of Mr.
Bates. When we first noticed them, about 4 P. M., they had probably just
commenced their flight. It continued until nearly 7 P. M., or a
considerable time after sundown. The next morning, there was not an
individual, winged or wingless, to be seen above ground; the nest itself
was comparatively empty; and what few occupants there were seemed to be
in a semi-torpid condition. Were they simply resting after the fatigue
and excitement of yesterday?

"It was not possible for us to calculate what proportion of these winged
ants were carried by the wind too far to return to their old home; but
certainly a large proportion were caught by the surrounding trees; and
we found, on search, some of these crawling down the trunks of the
trees, with their wings in a damaged condition. How near the trees must
be for them to reach their old home, we should like to learn; and what
tells them, 'which road to take?' Dr. Duncan states,[34] 'It was
formerly supposed that the females which alighted at a great distance
from their old nests returned again, but Huber, having great doubts
upon this subject, found that some of them, after having left the males,
fell on to the ground in out-of-the-way places, whence they could not
possibly return to the original nest!' We unfortunately did not note the
sex of those individuals that we intercepted in their return (?) trip;
but we can not help expressing our belief that, at least in this case,
there was scarcely an appreciable amount of 'returning' on the part of
those whose exodus we have just described; although so many were caught
by the nearer trees and shrubbery. Is it probable that these insects
could find their way to a small underground nest, where there was no
'travel' in the vicinity, other than the steady departure of
individuals, who, like themselves, were terribly bothered with the wings
they were carrying about with them?" (_American Naturalist._)

We have noticed that those females that do not return to the old nest
found new ones. In Maine and Massachusetts we have for several
successive years noticed the swarming of certain species of ants during
an unusually warm and sultry day early in September.

The autumnal brood of Plant lice now occur in great numbers on various
plants. The last brood, however, does not consist exclusively of males
and females, for of some of the wingless individuals previously supposed
to be perfect insects of both sexes, Dr. W. I. Burnett found that many
were in reality of the ordinary gemmiparous form, such as those
composing the early summer broods.

The White Pine Plant lice (Lachnus strobi) may be seen laying their long
string of black oval eggs on the needles of the pine. They are
accompanied by hosts of two-winged flies, Ichneumons, and in the night
by many moths which feed on the Aphis-honey they secrete, and which
drops upon the leaves beneath.

FOOTNOTES:

[Footnote 30: The right side represents the under side of the wings.]

[Footnote

[Footnote 32: See "Proceedings of the Essex Institute," vol. iv, p.
105.]

[Footnote 33: Naturalist on the River Amazons, vol. 1, p. 32.]

[Footnote 34: Transformations of Insects, p. 205.]




INDEX.


  Abraxas ribearia, 202.

  Acarus, 124.

  Acceleration, theory of evolution by, 167.

  Achorutes, 145.

  Adela, 189.

  Agrion, 109.

  Agrion, egg-parasite of, 164.

  Agrotis, 197.

  Alternation of generations, 168.

  Alypia, 57, 197.

  American tent caterpillar, 187.

  Amnion, 166.

  Ancestral forms, 151.

  Andrena, 31, 45, 192.

  Angle worms, 189.

  Annelida, 161, 170.

  Anopheles, 189.

  Ant, 217.

  Antenna, origin of, 174.

  Antherophagus, 49.

  Ant lion, 115, 182.

  Ants, 189.

  Anura, 136, 145, 147.

  Anurida, 146.

  Apathus, 47.

  Aphis, 151, 203.

  Aphis eater, 75.

  Aphis of grain, 209.

  Apple borer, 208.

  Apple insects, 83.

  Apple tree borer, 187.

  April, insects of, 187.

  Agonum, 191.

  Aquarium, 195.

  Arachnida, ancestry of, 189.

  Archetype, 186.

  Archetypes in Insects, 150.

  Arctia, 197.

  Argas, 123.

  Argynnis, 193, 197.

  Army worm, 55.

  Arrhenodes, 206.

  Arthropoda, 166.

  Aspidiotus, 203.

  Assmus, Edward, on parasites of honey bee, 39.

  Astoma, 122, 159.

  August, insects of, 209.


  Band, primitive, 163, 167.

  Bark borer, 188, 216.

  Bark louse, 203.

  Barnacle, 155.

  Bed bug, 96, 183.

  Bees, 17, 168, 206.

  Bee louse, 41.

  Beneficial insects, 190.

  Billings on Eophyton, 158.

  Bird tick, 84.

  Black fly, 73.

  Blight insect, 203.

  Bombardier beetle, 191.

  Borer, 187.

  Bot fly, 77.

  Botrytis, 47.

  Brachinus, 191.

  Brauer, F., on ancestry of insects, 157.
    On two larval forms, 175.

  Braula, 41.

  Breeze fly, 74.

  Brephos, 189.

  Bristle tail, 127.

  Bruchus, 188.

  Buprestis, 206.


  Cabbage butterfly, 55, 207.

  Caddis fly, 153.

  Caddis fly larva, 178.

  Caddis worm, 195.

  Calendar, Insect, 187.

  Caloptenus, 211.

  Calosoma, 190.

  Campodea, 133, 159, 170, 178.

  Campodea-stage of insects, 157.

  Canker worm, 187, 201.

  Carabidæ, 189, 190.

  Carabus, 191.

  Carboniferous insects, 158.
    Myriopods, 158.
    Scorpion, 158.

  Carpenter bee, 192.

  Carpet fly, 75.

  Case worms, 195.

  Casnonia, 191.

  Caterpillar, origin of, 175, 179.

  Cecidomyia, 168, 196, 203.

  Cecidomyia tritici, 197.

  Centipede, 149.

  Ceratina, 24, 192.

  Ceresa, 209.

  Cestodes, 162.

  Cheese maggot, 83.

  Cheese mite, 124.

  Cheyletus, 119.

  Chigoe, 86.

  Chinch bug, 55, 203.

  Chionea, 85.

  Chironomus, 168, 189.

  Chloëon, 170, 180.

  Chrysobothris, 206.

  Chrysopa, 171, 182, 208.

  Chrysophanus, 193, 207.

  Cicada, 212.

  Cicindela, 189.

  Clothes moth, 64, 188.

  Coccinella, 204.

  Coddling moth, 188.

  Coleopterous larvæ, 175.

  Collembola, 133, 159.

  Comprehensive type, 154.

  Compsidea, 90.

  Conotrachelus, 194.

  Copepoda, 167.

  Corydalus, mandibles of, 182.

  Crab, 155, 156.

  Crustacea, differences of from insects, 157.

  Currant borer, 204.

  Currant worm, 202.

  Cut worm, 197.

  Cyclops-like stage, 162.

  Cynips, 193.


  Daddy-long-legs, 194.

  Dawson's discovery of fossil myriopods, 159.

  Dawson on fossil land plants of Upper Silurian, 158.

  Degeeria, 143.

  Demodex, 125, 148, 160.

  Devil's darning-needle, 106.

  Devonian formation, insects in, 158.

  Diabrotica, 194.

  Dicerca, 206.

  Dicyrtoma, 142.

  Diplax, 113, 154.

  Dipterous gall fly, 196.

  Dipterous larvæ, 175.

  Dohrn, Anton, on ancestry of insects, 169.

  Dragon fly, 106, 171, 195.

  Dujardinia, 170.

  Dytiscus, 182.


  Ear wig, 136.

  Echinoderes, 169.

  Egg parasites, 201.

  Egg parasite of Agrion, 164.

  Eggs of canker worm, 187.

  Elm tree insects, 90.

  Embryology, comparative. 167.

  Embryology of Podura, 140.

  Ennomos, 216.

  Ephemera, 154, 194.

  Ephydra, 174.

  Eruciform larva, 175.

  Euphorberia, 158.

  Evolution theory, 152.

  Eyes of insects, 185.


  Fabre on hyper-metamorphosis, 43.

  Fall weaver, 197.

  Fire fly, 202.

  Flea, 86.

  Forceps Tail, 171.

  Forficula, 136.

  Fossil insects, 158.
    Myriopods, 158.
    Scorpion, 158.

  Foul brood, 40.


  Gad fly, 74.

  Galley worm, 149.

  Gall flies, 193.

  Gall fly, 72, 203.

  Gall fly, two-winged, 196.

  Gamasus, 120.

  Ganin on embryology of insects, 161.

  Gegenbaur on tracheæ, 172.

  Generalized types, 154.

  Generation, alternate, 168.

  Gerris, 210.

  Gerris, egg-parasite of, 166.

  Gills of insects, 172.

  Gnat, 71, 189.

  Gonocerus, 204.

  Gordius, 46.

  Gortyna, 215.

  Grain Aphis, 209.

  Grape insects, 57.

  Grape leaf roller, 205.

  Grape saw fly, 207.

  Grapta, 189, 204, 207.

  Grasshopper, 181, 211.

  Green head, 74.

  Grimm on parthenogenesis, 168.


  Hæckel, Ernst, on ancestry of insects, 156.

  Hairs of insects, 185.

  Hair worm, 46.

  Halictus, 31, 192.

  Handily, A. H., on Thysanura, 133.

  Hartt's discovery of fossil insects in New Brunswick, 158.

  Harvest bugs, 122.

  Haustellate insects, 183.

  Hawk moth, 194, 200.

  Head of insects, mode of formation of, 174.

  Heart, iv.

  Hemiptera, 209.

  Hemipterous larvæ, 175.

  Hessian fly, 72, 196.

  Heteropus, 126.

  Hibernation of insects, 192.

  Hirudo, 166.

  Histolysis, 168.

  Histriobdella, 166.

  Histriobdella stage of Polynema, 164.

  Hop vine moth, 215.

  Horse tick, 84.

  House fly, 80.

  Humble bee parasite, 215.

  Humming bird moth, 194.

  Hunt on organic life in the Laurentian period, 158.

  Hylobius pales, 188.

  Hylurgus terebrans, 188.

  Hymenopterous larvæ, 175.

  Hyper-metamorphosis of insects, 166.

  Hyphantria, 204.

  Hypodermis, 163.


  Ichneumon, 161, 201.

  Illinois, fossil insects of, 159.

  Ilythia, 215.

  Injurious insects, 190.

  Insects, ancestry of, 150.

  Insects, archetypes of, 150.

  Insects, beneficial, 190.

  Insect calendar, 187.

  Insects, embryology of, 154, 155.

  Insects, flight of, ix.

  Insects in the Devonian formation, 158.

  Insects, metamorphosis of, 166.

  Insects, origin of, 156.

  Insects, reason in, 30, 37.

  Insects, respiration of, 171.

  Insects, senses of, xiii.

  Insects, sexes in, 52.

  Insects, transformations of, xiv, 50.

  Insects, wingless, 171.

  Intestinal worms, 161.

  Isotoma, 140, 143.

  Itch mite, 125.

  Ixodes, 117, 123.


  Japyx, 132.

  Jaws of insects, origin of, 174.

  Jelly fishes, 168.

  Joint worm, 55.

  Julus, 149, 169.

  Julus, embryology of, 164.

  July, insects of, 206.

  June, insects of, 200.


  Kowaleusky's researches on embryology of worms, 169.


  Labium, vi, 165.

  Lachnosterna fusca, 202.

  Lachnus, 220.

  Lady bird, 208.

  Larva, ernciform, 175.
    Leptiform, 175.
    Two kinds of, 175.

  Larval skin of crustacea, 166.

  Leaf cutter bee, 26, 206.

  Leaf roller, 188, 197, 205.

  Leeches, 166.

  Legs of insects, 173.

  Leidy, J., on internal parasites of insects, 39, 46.

  Lepidocyrtus, 144.

  Lepidopterous larvæ, 175.

  Lepisma, 128.

  Leptiform larva, 175.

  Leptus, 120, 155, 159.

  Lespès, on sense of hearing in insects, xiv.

  Leucania, 55.

  Leuckart on embryology of Hirudo, 168.
    Parthenogenesis, 168.

  Libellula, 107, 195.

  Linden tree insects, 90.

  Linguatula, 160.

  Lipura, 145.

  Lithobius, 178.

  Locust tree insects, 93.

  Louse, 96, 154.

  Lubbock's discovery of Pauropus, 149.

  Lubbock, Sir John, on Thysanura, 133;
    on the origin of insects, 159, 173.

  Machilis, 128.

  Macrodactylus, 206.

  Macrosila cluentius, 184.

  Maggot, origin of, 175, 178.

  Mandible, vi.

  Mandibles of moths, 183.

  Mandibulate insects, 183.

  Mange mite, 125.

  Marey on the flight of insects, ix.

  Mason bee, 192.

  Maxillæ, vi.

  Maxilla of moths, 184.

  May beetle, 202.

  May fly, 194.

  May, insects of, 192.

  Mazonia, 158.

  Meat fly, 82.

  Meek's discovery of fossil insects in Illinois, 158.

  Megachile, 26.

  Melipona, 18.

  Melitæa, 193, 207.

  Melitæa Phaeton, 204.

  Meloë, 21, 42.

  Metamorphosis of insects, 166, 175;
    origin of, 179.

  Miastor, 168.

  Microgaster, 49.

  Mites, 116, 149.

  Mosquito, 68.

  Mosquito hawk, 195.

  Mouth-parts of insects, origin of, 173.

  Mucor, 47.

  Mud dauber, 207.

  Müller, Fritz, on ancestry of insects, 156, 169.

  Müller, J., on sight in insects, xiii.

  Murray's discovery of Eophyton in America, 158.

  Musca, 80, 168.

  Muscardine, 47.

  Mycetobia, 73.

  Myobia, 169.

  Myriopoda, 149.
    Ancestry of, 159.


  Nannophya, 114.

  Nauplius, 155, 160.

  Nebalia, 182.

  Nephelis, 166.

  Nephopteryx, 49.

  Neuropterous larvæ, 175.

  New Brunswick, fossil insects of, 158.

  Newport, on embryology of Julus, 164.

  Nicoletia, 131.

  Nomada, 38.

  Notonecta, 209.

  Nova Scotia, fossil insects of, 159.


  Ocypete, 159.

  Odynerus, 207.

  Oecanthus, 216.

  Oil beetle, 188.

  Onion fly, 49.

  Ophioneurus, embryology of, 165.

  Orchesella, 143.

  Ornithomyia, 84.

  Orthopterous larvæ, 175.

  Osmia, 27.

  Otiorhynchus, 199.

  Ovipositor of Cicada, 185.


  Palpus, vi.
    Origin of, 174.

  Pangus, 191.

  Panorpa, 171, 209.

  Paper wasp, 207.

  Papilio Asterias, 200.

  Papirins, 142.

  Parasite of insect eggs, 164.

  Parsnip butterfly, 200.

  Parthenogenesis, 168.

  Pasteur on the silk worm disease, 63.

  Pauropus, 149, 154, 158, 171.

  Peach borer, 206.

  Pear slug, 207.

  Pea weevil, 188.

  Peck, W. D., on the habits of Stylops and Xenos, 45, 46.

  Pelopæus, 207.

  Pentastoma, 148, 160.

  Peripatus, 161.

  Perla, 154.

  Phora, 40.

  Phymata, 211.

  Phytocoris, 211.

  Pickle worm, 57.

  Pieris, 55, 197, 207.

  Pieris brassicæ, egg parasite of, 165.

  Pine plant louse, 220.

  Pine weevil, 188, 199.

  Piophila, 83.

  Pirates, 210.

  Pissodes strobi, 188.

  Plan of structure, 186.

  Plant louse, 220.

  Platygaster, embryology of, 161.

  Plum weevil, 194.

  Podura, 133, 135, 144, 153, 154, 159, 170.
    Catch of, 139.
    Spring of, 137.

  Podurids, the ancestors of the true insects, 157.

  Poisonous insects, 214.

  Polynema, embryology of, 164.

  Poplar tree insects, 92.

  Potato insects, 63.

  Prelarval stage of ichneumons, 168.

  Primitive band, 163, 166.

  Primitive insects, 175.

  Prionus, 93.

  Procris, 60.

  Protoleptus, 172, 174.

  Pseudoneuroptera, 178.

  Ptinus fur, 200.

  Putnam, F. W., on habits of the bees, 19, 26.

  Pyrrharctia, 207.


  Ranatra, 210.

  Rat-tailed fly, 76.

  Reduvius, 210.

  Reproduction, virgin, 168.

  Respiration of insects, 171.

  Retardation, theory of evolution by, 167.

  Rose beetle, 206.

  Rose saw fly, 196.

  Rose slug, 207.

  Rotatoria, ancestors of crustacea, 169.


  Salpa, 168.

  Saperda, 91, 208.

  Sarcoptes, 125.

  Saw fly, 196, 207.

  Saw of saw fly, 185.

  Schiödte on the mouth-parts of the louse, 96.

  Scolopocryptops, 149.

  Scorpion, fossil, 158.

  Scudder on fossil insects of New Brunswick and Illinois, 158.

  Seira, 143.

  Selandria, 207.

  Selandria rosæ, 196.

  September, insects of, 216.

  Sesia, 194.

  Seventeen year locust, 212.

  Sexes, origin of, 152.

  Sheep tick, 85.

  Shrimp, 155.

  Siebold, T. von, on the ears of grasshoppers, xiv.

  Siebold on parthenogenesis, 168.

  Silk worm, 51.

  Silver witches, 128.

  Simulium, 73.

  Sitaris, 44.

  Smith, F., on stingless bees, 18.
    On parasitic bees, 37.

  Smynthurus, 142.

  Species, origin of, 152.

  Sphinx, 194, 197, 200, 207.

  Spider, 155.

  Spider fly, 85.

  Spindle worm, 215.

  Spinneret of caterpillars, 183;
    of spiders, 185.

  Spring, insects of, 187.

  Spring of Podura, 185.

  Spring tail, 127.

  Squash beetle, 194.

  Squash bug, 204.

  Sting of bee, 185.

  Sting, origin of, 165.

  Stylops, 21, 45, 152, 179, 188.

  Sucker of insects, 183.

  Sugar mite, 124.

  Swarming of ants, 217.

  Syllis, 170.

  Syrphus, 75.


  Tabanus, 74.

  Tachina, 39, 189.

  Tailor bee, 26.

  Tardigrade, 150, 160.

  Teleas, embryology of, 166.

  Templetonia, 143.

  Tent caterpillar, 187.

  Tenthredo, 207.

  Tettigonia, 209.

  Thanaos, 197.

  Thecla, 197.

  Thorax of insects, 173.

  Thysanura, 127, 154.

  Ticks, 116.

  Tinea, 64, 188.

  Tipula, 194.

  Tomicus, 199.

  Tomocerus, 137, 143.

  Tongue of insects, 183.

  Torell's discovery of Eophyton in Sweden, 158.

  Tortrices, 205.

  Tortricidæ, 188.

  Trachea, iv.

  Tracheæ, absence of in Polynema, 165.

  Tracheæ, origin of, 171.

  Tree cricket, 216.

  Trichocera hyemalis, 189.

  Trichodes, 42.

  Trigona, 18.

  Trochilium tipuliforme, 205.

  Trombidium, 120, 159.

  Trouvelot, L., on amount eaten by silk worms, vii, 60.

  Turnip butterfly, 197.


  Uhler, P. R., on habits of the dragon fly, 107, 110.


  Verrill, A. E., on the parasites of man and the domestic animals, 84.

  Vine dresser, 59.

  Virgin reproduction, 168.


  Wasp, 206.

  Water bear, 150.

  Water boatman, 166, 209.

  Waterhouse, G. R., on habits of Osmia, 27.

  Weevil, 179, 188, 194.

  Weismann on growth of insects, 164.

  West, Tuffen, on the foot of the fly, viii.

  Wheat midge, 197.

  Wine fly, 83.

  Wingless insects, 171.

  Wings of insects as respiratory organs, 165.

  Wings, origin of, 172.

  Worthen's discovery of fossil insects in Illinois, 158.

  Worms, the ancestors of insects, 160, 169.

  Wyman, Jeffries, on the cells of the honey bee, 17.


  Xenos, 46.

  Xylobius, 159.

  Xylocopa, 21.


  Zaddach on development of worms, insects and crustaceans, 169.

  Zoëa, 156.


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End of Project Gutenberg's Our Common Insects, by Alpheus Spring  Packard