TREASURY DEPARTMENT
                  UNITED STATES PUBLIC HEALTH SERVICE
                   HUGH S. CUMMING, Surgeon General


                              THE BEDBUG

             ITS RELATION TO PUBLIC HEALTH, ITS HABITS AND
                 LIFE HISTORY, AND METHODS OF CONTROL

                            REPRINT No. 626
                               FROM THE
                         PUBLIC HEALTH REPORTS
                           December 10, 1920
                           (Pages 2964–2970)
                        [Revised edition, 1924]


                            [Illustration]


                              WASHINGTON
                      GOVERNMENT PRINTING OFFICE
                                 1924




                            THE BEDBUG.[1]

      Its Relation to Public Health, its Habits and Life History,
                        and Methods of Control.

    [1] Reprint from the Public Health Reports, vol. 35, No. 50,
    December 10, 1920, pp. 2964–2970.


The bedbug is one of the numerous insects which have been suspected
of conveying disease to man. Compared with such insect pests as
mosquitoes, lice, and fleas, however, its rôle is decidedly a minor
one. It has been claimed that the bedbug can take up the microparasites
of European relapsing fever, plague, and possibly leprosy, along with
the blood of men or animals suffering from these diseases. It is
also possible that in rare instances the bedbug may transmit plague
or European relapsing fever to man. On the other hand, there is no
convincing evidence that the bedbug is the usual and ordinary insect
transmitter of these or any other diseases at present known to us.

If the bedbug acts as a transmitter of disease, it apparently does so
by the accidental carriage of disease elements on the mouth parts;
but this occurs only under the most favorable conditions. These would
require, first, the presence of great numbers of microparasites on
the skin or in the blood of a man or animal sick with some disease
transmissible to man by subcutaneous inoculation; second, it would
probably be necessary that there should be many bugs biting in order
that one or more of them should bite some healthy person within a
rather short space of time after these insects had fed on the infected
individual.

In actual practice these conditions would be found only in the most
filthy and insanitary surroundings and would call for drastic measures
to exterminate all vermin. It is, of course, possible that under
unsettled conditions where sick and well are crowded together with
no facilities for cleanliness, bedbugs might act as transmitters of
septicemic diseases. Experience has shown that under such grossly
insanitary conditions such insects as fleas and lice appear to be
and are far more dangerous as carriers of disease. Special measures
for their extermination should be taken. Added precautions for the
examination of bedbugs under these conditions would probably not be
justified by the results.

Notwithstanding the minor rôle which must be assigned the bedbug as
a carrier of disease, its presence is an offense against sanitary
decency. Its bites are quite poisonous to some people and its odor
is most disagreeable; and every effort should be made to keep all
dwellings, hospitals, ships, and other premises free from these
disgusting insects.

Dr. L. O. Howard, Chief of the Bureau of Entomology, United States
Department of Agriculture, and consultant United States Public Health
Service, has permitted the quotation of the following passages
from Farmer’s Bulletin No. 754, by C. L. Marlatt, which gives an
authoritative account of the habits, life history, and the means of
control of these insects.


                       “General Characteristics.

“The bedbug belongs to the order Hemiptera, which includes the true
bugs or piercing insects, characterized by possessing a piercing and
sucking beak. The bedbug is to man what the chinch bug is to grains or
the squash bug to cucurbs. Like nearly all the insects parasitic on
animals, however, it is degraded structurally, its parasitic nature
and the slight necessity for extensive locomotion having resulted,
after many ages doubtless, in the loss of wings and the assumption of
a comparatively simple structure. Before feeding, the adult is much
flattened, oval, and in color is rust red, with the abdomen more or
less tinged with black. When engorged, the body becomes much bloated
and elongated and brightly colored from the ingested blood. The
wings are represented by the merest rudiments, barely recognizable
pads, and the simple eyes or ocelli of most other true bugs are
lacking. The absence of wings is a most fortunate circumstance, since
otherwise there would be no safety from it even for the most careful
of housekeepers. Some slight variation in length of wing pads has been
observed, but none with wings showing any considerable development has
ever been found.


                       “Habits and Life History.

“The bedbug is normally nocturnal in habits and displays a certain
degree of wariness, caution, and intelligence in its efforts at
concealment during the day. Under the stress of hunger, however, it
will emerge from its place of concealment in a well-lighted room at
night, so that under such circumstances keeping the gas or electric
light burning is not a complete protection. It has been known under
similar conditions to attack human beings voraciously in broad
daylight. It usually leaves its victim as soon as it has become
engorged with blood and retires to its normal place of concealment,
either in cracks in the bedstead, especially if the latter be one of
the wooden variety, or behind wainscoting, or under loose wall paper;
and in these and similar places it manifests its gregarious habit by
collecting in masses. It thrives particularly in filthy apartments and
in old houses which are full of cracks and crevices, in which it can
conceal itself beyond easy reach. As just noted, the old-fashioned,
heavy, wooden-slatted bedsteads afford especially favorable situations
for the concealment and multiplication of this insect, and the general
use in later years of iron and brass bedsteads has very greatly
facilitated its eradication. Such beds, however, do not insure safety,
as the insects are able to find places of concealment even about such
beds, or get to them readily from their other hiding places.

“The bedbug takes from 5 to 10 minutes to become bloated with blood,
and then retires to its place of concealment for 6 to 10 days for the
quiet digestion of its enormous meal, and for subsequent molting, or
reproduction if in the adult stage.”

“The eggs hatch in a week or 10 days in the hot weather of midsummer,
but cold may lengthen or even double this incubation period or check
development altogether. The young escape by pushing up the lid-like
top with its projecting rim. When first emerged, they are yellowish
white and nearly transparent, the brown color of the more mature insect
increasing with the later molts.”

“Unfavorable conditions of temperature and food will necessarily
result in great variation in the number of generations annually and
in the rate of multiplication, but allowing for reasonable checks on
development, there may be at least four successive broods in a year in
houses kept well heated in winter.”


                         “Food and Longevity.

“Under normal conditions the food of the common bedbug is obtained
from human beings only, and no other unforced feeding habit has been
reported. It is easily possible, however, to force the bedbug to feed
on mice, rats, birds, etc., and probably it may do so occasionally
in nature in the absence of its normal host. The abundance of this
insect in houses which have long been untenanted may occasionally be
accounted for by such other sources of food, but probably normally such
infestation can be explained by the natural longevity of the insect
and its ability to survive for practically a year, and perhaps more,
without food.”


                      “Influence of Temperature.

“As a messmate of human beings in dwelling houses, the bedbug is
normally protected from extreme cold and is known to be an abundant
and serious pest far north. In fact, it is often more troublesome in
north temperate latitudes than farther south. This may be accounted
for partly by the fact that the bedbug is very sensitive to high
temperatures, and a temperature of 96° to 100° F. or more, accompanied
with a fairly high degree of humidity, results in the death of
large numbers of the bugs. The mature or partly mature bedbugs can
stand comparatively low temperatures, even below freezing, for a
considerable period. The eggs and newly hatched larvæ, however, succumb
to a temperature below freezing, if this condition is prolonged for
from 15 days to a month. The feeding and developing activity of the
insect practically ceases at 60° F., the insect remaining quiescent and
in semihibernation at temperatures below this point. The most favorable
temperatures for activity are between 60° and 98° F. The activity of
the insect is controlled entirely by temperature and food supply, and,
therefore, in heated houses the insect may remain active throughout the
winter. There is some protection in winter, therefore, in sleeping in
cold bedrooms.”


                       “The Bite of the Bedbug.

“The bite of the bedbug is decidedly poisonous to some individuals,
resulting in a slight swelling and disagreeable inflammation. To such
persons the presence of bedbugs is sufficient to cause the greatest
uneasiness, if not to put sleep and rest entirely out of the question.
With others, however, who are less sensitive, the presence of the bugs
may not be recognized at all, and, except for the occasional staining
of the linen by a crushed individual, their presence might be entirely
overlooked. The inflammation experienced by sensitive persons seems to
result chiefly from the puncture of the skin by the sharp piercing setæ
which constitute the puncturing element of the mouth parts, as there
seems to be no secretion of poison other than the natural fluids of the
mouth.

“The biting organ of the bedbug is similar to that of other insects of
its order. It consists of a rather heavy, fleshy under lip (the only
part ordinarily seen in examining the insect), within which lie four
thread-like hard filaments or setæ which glide over one another with an
alternating motion and pierce the flesh. The blood is drawn up through
the beak, which is closely applied to the point of puncture, and the
alternating motion of the setæ in the flesh causes the blood to flow
more freely.

“To allay the irritation set up by the bite of the bedbug, peroxide of
hydrogen or dioxygen may be used with good results.

“Tincture of iodine either at ordinary or double strength is also a
good counterirritant for use in cases of flea, mosquito, bedbug, and
other insect bites, but should be used with caution on the tender skin
of small children and on those who are affected with or disposed to
eczemic disorders.”


                    “Natural Enemies of the Bedbug.

“Living always in houses as it does and being well concealed, the
bedbug is not normally subject to much if any control by natural
enemies. Certain other household insects, however, do occasionally
prey upon the bedbug, as, for example, the house centipede and the
common little red house ant. Such enemies, however, are of very small
importance and yield little, if any, effective control except under
very exceptional circumstances.”


                              “Remedies.

“Undoubtedly the most efficient remedy for the bedbug is to fumigate
the infested house or rooms with hydrocyanic-acid gas. This gas will
penetrate into every crevice in the house or room where the bedbugs
conceal themselves and has an immediate effectiveness which gives
it an important recommendation, especially when the infestation is
considerable or of long standing. This method of fumigation should be
intelligently employed, as the gas is deadly poisonous.” Five ounces
of potassium cyanide per 1,000 cubic feet of space should be employed;
exposure, one hour.[2] Ten ounces per 1,000 cubic feet would be better.

    [2] Creel, R. H., and Faget, F. M., Cyanide Gas for the
    Destruction of Insects, with Special Reference to Mosquitoes,
    Fleas, Body Lice, and Bedbugs: Public Health Reports, June 9,
    1916, pp. 1464–1475; Reprint No. 343.

“The fumes of burning sulphur are also a very efficient means of
control where the conditions are such that this method can be used,
readily destroying the insect in all stages, including the egg. The
treatment is inexpensive compared with the use of hydrocyanic-acid gas
and offers much less risk of danger to human beings. There is, however,
a considerable risk of injury to household fabrics, furnishings, and
wall papers from the strong bleaching quality of sulphur fumes. This
danger will be somewhat diminished if the fumigation can be done at a
time when the room or house is thoroughly dried out, as in winter by a
furnace or other heating system. Further precautions should be taken
by removing all metallic surfaces from the room or building, or by
protecting them with a coating of vaseline.”

Four pounds of sulphur are recommended for each 1,000 cubic feet of
space, and the building should be closed for the treatment for at least
five or six hours. “Sulphur candles may be used where available, or
the sulphurous gas or fumes can be generated by burning the sulphur
in a dish placed in the center of the room, and for protection set
within a larger vessel. Thoroughgoing precautions must be taken to
prevent accidental overflowing or the starting of a fire, and after the
fumigation the house should be given a thorough airing.

“Other gases have been experimented with, such as formalin and the
vapors of benzine, naphthalene, and camphor, but these gases are of
little value. Similarly, insect powders are of little value, largely
from the difficulty of getting them into the crevices and other places
of concealment of the insects.

“The old-fashioned household remedies referred to below are effective
enough, though at a greater cost of time and personal effort. They
will, however, be often of much service in the case of slight or
recent infestations, or where the employment of more poisonous and
troublesome gases is objected to or is impracticable. Of these simple
methods of control perhaps the most efficient is in very liberal
applications of benzine or kerosene, or any other of the lighter
petroleum oils, introduced with small brushes or feathers, or by
injecting with syringes into all crevices of beds, furniture, or walls
where the insects may have concealed themselves. Corrosive sublimate is
also of value, and oil of turpentine may be used in the same way. The
liberal use of hot water, wherever it may be employed without danger
to furniture, etc., is also an effectual method of destroying both
eggs and active bugs.[3] A 5 per cent solution of compound solution of
cresol (liquor cresolis compositus) in kerosene forcibly applied with a
large plant sprayer is effective if frequently applied.

    [3] “A remedy for the bedbug has been devised by Mr. R.
    H. Pettit (‘Notes on two insecticidal agents,’ 10th Rpt.
    Mich. Acad. Sci., p. 159–160, 1908) as a substitute for
    hydrocyanic-acid gas and sulphur, and is reported to have
    proved very successful. The preparation of this insecticide and
    its application are described as follows:

    “Alcohol is drawn through pyrethrum in a funnel until the
    powder is well washed and a large part of the resinous
    principle extracted. To do this, the powder is placed in a
    large funnel with filter-plate and a layer of cotton wool at
    the bottom. An aspirator is attached and the alcohol is at
    first slowly and later rapidly sucked through six or eight
    times, during which operation it becomes highly colored.
    To this liquid as a basis, are added several oils to give
    permanence to the application. Both alcohol and pyrethrum
    evaporate so quickly that it was thought best to carry in some
    heavier volatile oils whose effects would last several days or
    even weeks. The formula when completed stands as follows:

    “To the extract made by washing 400 grams of pyrethrum with
    2,000 c. c. of strong alcohol, are added――

        50 grams gum camphor.
        150 c. c. cedar wood oil.
        25 grams oil citronella.
        25 grams oil lavender.

    “The application is best made with a large-sized atomizer, one
    holding a pint or more and working with a piston instead of
    a rubber bulb. * * * To obtain the best results, repeat the
    treatment after about two weeks. We have tried this mixture
    repeatedly and with uniformly gratifying results. Usually
    one application, if thoroughly made, put a period to the
    complaints, about eight to ten ounces being required in an
    average sleeping room. The odor remains some little time in a
    room, but is not disagreeable to the average person.

    “This remedy can be readily prepared by a pharmacist in any
    drug store.”

“Various bedbug remedies and mixtures are for sale, most of them
containing one or another of the ingredients mentioned, and these are
frequently of value. The great desideratum, however, in a case of this
kind, is a daily inspection of beds and bedding, particularly the seams
and tufting of mattresses, and of all crevices and locations about the
premises where these vermin may have gone for concealment. A vigorous
campaign should, in the course of a week or so at the outside, result
in the extermination of this very obnoxious and embarrassing pest.”

“_Temperature control._――The possibility of temperature control is
indicated in the discussion elsewhere of the effect of temperature on
this insect. A temperature maintained below freezing for 10 or 15 days
destroys the eggs, and this temperature continued for 15 days to a
month will destroy the newly hatched young. It may be, therefore, that
if infested houses in cold climates should be opened up and allowed
to remain at a temperature well below freezing for a considerable
period, all eggs and the young, and possibly most if not all of the
adults, would be exterminated. This method of control might perhaps be
practicable at least in the case of summer houses in the North which
are left untenanted in the winter.

“The maintaining of high temperatures may be an even more efficient
method of control. The activity of the bedbug is at its greatest
between 60° and 70° to 75°. As indicated elsewhere, in a temperature
of 96° to 100° F., accompanied with a high degree of humidity, newly
hatched bedbugs perish within a few days, and, if this temperature is
raised to 113° F., in a few minutes.[4] A temperature of 113° will
also destroy the eggs, and with these higher temperatures the item of
humidity is not apparently important.”

    [4] EDITORIAL NOTE.――An account of successful use of live steam
    to eradicate bedbugs in bunkhouses, as practiced by a lumber
    company in Oregon, was published in Public Health Reports, Nov.
    28, 1919, pp. 2713–2714. In that instance steam pipes were
    tapped, after closing all doors and windows, and a temperature
    of 160° F. was held for approximately 3 hours. The officials of
    the company stated that 2 months after the steaming no signs of
    bedbugs had been found.


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 Transcriber’s Notes:

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