Insects in relation to national defense


Material Information

Insects in relation to national defense
Series Title:
Its Circular no. 1-23. Feb. 1941-Jan. 1944
Added title page title:
Insects in relation to national defense, circular
Physical Description:
24 nos. in 1 v. : ill., photos., map, plans, diagrs. ; 23 cm.
United States -- Bureau of Entomology and Plant Quarantine
U.S. Govt. Print. Off.
Place of Publication:
Publication Date:


Subjects / Keywords:
Beneficial insects   ( lcsh )
Insect pests   ( lcsh )
Insecticides   ( lcsh )
Fumigation   ( lcsh )
World War, 1939-1945 -- Health aspects   ( lcsh )
serial   ( sobekcm )
non-fiction   ( marcgt )


General Note:
Reproduced from type-written copy.
General Note:
Includes bibliographical references.

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University of Florida
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All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029081698
oclc - 09471812
lcc - SB931 .U44
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Full Text




TO 0



Circular 9


May 1941






Circular 9 Lice

Table of Contents


itroduction............. .. . .... ... ....
Lnds of Lice..............................
Head Lice...............................
Body Lice . . ... . .....** ..........
Pubic Lice................ . .. .. ..
Head Lice ........ ....... ....... ......
Treatment of hair.*................
Treatment of hats......................
Body Lice... . ...... .. ... ...... ......
Treatment of body*..........*..........
Treatment of clothing..***.....****....
Dry heat..... ........... 9... *......
Hot water............................
Storage.... .... .... ........ ..... .....
Natural means........................
Treatment of infested quarters..*****.......
Pubic Lice...............................
Treatment of body..*.......** ...** .*......*****..

* 999



* 9.
* *.

Treatment of clothing.......




Circular 9 Lice 2

Dry heat................................. 16
Hot water................................ 16
Steam.......... .. ...................... 16
Chemicals................................ 16
Fumigation............................... 16
Storage....................... .......... 16
Natural means............................ 16
Treatment of infested quarters......*.-..... 17
References..................................... 17


Lice become numerous and a general pest wherever
groups of individuals are associated under conditions
where strict cleanliness is not maintained. Infested
individuals are always about, and care must be taken
to prevent spreading and establishment of the lice
they harbor.

These parasites annoy man and are vectors of
serious diseases. Typhus fever, relapsing fever, and
trench fever are louse-borne to man. Fortunately
louse-borne typhus and relapsing fevers are not wide-
spread in the continental United States and tropical

Lice found on man feed by sucking blood. They
insert their mouthparts and attach for from 3 to 10
minutes. Extreme irritation occurs during and after
feeding, and much discomfort results from scratching
and loss of sleep. Long-continued infestations may
cause chronic irritation and coloring of the affected

Man is attacked by sucking lice only. They
are: the head louse (Pediculus humanus humanus L.);
the body louse, or "cootie" (PesdiCuus humanus cor-
poris Deg.); and the pubic louse, or "crab" louise
(Phthirus pubis (L.)).

Circular 9 Lice 3

Geographically, human lice are found in all
climates from the Arctic to the Tropics.

Human lice do not breed on animals other than
man. Gorillas, apes, monkeys, dogs, cats, cattle,
hogs, and horses have their own species, and do not
maintain colonies of lice which may infest man.


If there is doubt as to what kind of louse is
encountered at any time, it is suggested that speci-
mens be sent to the Bureau of Entomology and Plant
Quarantine, U. S. Department of Agriculture, Washing-
ton, D. C., for examination by a specialist. Lice
may be forwarded in small vials containing 70% (ordi-
nary rubbing) alcohol, carefully packed, and labeled
with name of collector, locality and date of collec-
tion, and animal from which taken.


All lice have three stages: egg, larva, and
adult. The larva-, or immature form, is similar to the
adult, but smaller and lighter in color. Louse eggs/
are called "nits." The length of time for completion
of a life cycle varies according to the species and
conditions of temperature and humidity. Human lice
best carry on their life processes under conditions
similar to those found on the human body.

Head Lice

Head lice are found chiefly among the hairs
of the head where they may be seen as whitish or gray
insects (fig. 1) which move rapidly when disturbed.
The females are slightly larger than the males, some-
times attaining a length of 1/8 of an inch. They
have been reported from other hairy parts of the body,
also. After feeding they may be seen more readily

Circular 9 Lice

* /

Figure 1 Head louse, female.

Figure 2- Body louse, female.

Figure 4 Egg
of head louse
on a hair.

Figure 3 Pubic louse, male.

Figure 5-Egg
of pubic louse
on a hair.







Circular 9 Lice

because of the darker color which is visible through
their body covering. At oviposition, the female
louse securely cements each egg to a hair (fig. 4);
sometimes oviposition occurs in hats. Lice congre-
gate in the hair at the back of the head and behind
the ears. An infested head may be recognized by the
general distribution of "nits," accompanied in serious
cases by matted hair and scabby scalp.

The egg stage of the head louse varies from
5 to 10 days; 7 days is the usual period at about
90 to 96 F. Eggs are laid at the rate of 3 to 9
each day under normal conditions; a single female
lays from 200 to 300 eggs in a lifetime. The length
of time required for development from hatching until
the mature louse is ready to oviposit averages about
10 days. Adult head lice, fed intermittently, live
as long as 38 days, with an average of 27 days; but
continual access to a source of blood would undoubt-
edly make these figures vary.

Body Lice

Body lice, or cootiess," when mature, are gray,
rapidly moving insects, sometimes reaching 1/6 of
an inch in length, (fig. 2). They are found chiefly
on clothing where it comes in contact with the body,
such as underclothing close to the body, and on the
outside of outer clothing to some extent, such as
suspenders, pocket openings, etc. Stragglers may be
found on the body. Eggs are laid chiefly in the seams
and folds of clothing (fig. 6), preferably woolens
and flannels, although cottons and silks are sometimes
infested. Occasionally, eggs are found attached to
hairs of the body, such as on the chest and in the

The biology of the body louse is similar to
that of the head louse. The egg stage varies from 4
to 16 days at 79 to 98.6 F.; 8 days is the average
when kept on the human body under normal conditions.
Eggs are laid at the rate of from 3 to 14 daily, depend-
ing largely on whether feeding is interrupted or the

Circular 9 Lice

source of blood constantly available; 10 or 11 is
the average number when lice can feed constantly.
From 200 to 300 eggs are usually laid by one female
in its lifetime. The length of time required from
hatching until the mature louse is ready to oviposit
averages 8 days when lice are kept on the human body
under normal conditions. Adult body lice, fed inter-
mittently, live as long as 46 days, with an average
of 34 days. Unfed adults at 61 to 65 F. will live

Figure 6 Eggs of body louse along
seams of clothing.

as long as 7 days; at 98 they will live 3 days.
Newly hatched lice die within 24 hours unless given
access to food. Changes of temperature, as well as
interrupted feeding, retard the life processes of
body lice. A body louse has been observed to crawl
about 1 yard in 2 minutes 43 seconds.

Circular 9 Lice

Pubic Lice

Pubic lice, or "crab" lice (fig. 3), frequent
the pubic region, armpits, body hairs, and in some cases
are found in eyelashes, eyebrows, and have been report-
ed from beards and mustaches. They are crab-like in
form, with large, heavy legs that grasp hairs tightly
and allow the insects to feed and cling close against
the body. They are shorter and broader than the body
louse. Eggs are laid on the hairs of that part of
the body infested (fig. 5).

The egg stage of the pubic louse varies from
6 to 8 days under normal conditions; 16 to 18 days
is required for development from the time of hatching
until the mature louse is ready to oviposit. Under
normal conditions a female was observed to lay 26 eggs.
Adults and larvae die within two days after separation
from their host. While on the host, they appear to
feed almost constantly, and it is believed that such
adults live somewhat less than a month. Pubic lice
living on the host under normal conditions have been
observed to move around in an area of less than an

All three species are spread by physical con-
tact with infested individuals, scattering of infested
hairs, exchange of hats or clothing, or use of infested
towels. Head and body lice move rapidly and so are
capable of transferring from one host to another and
of even infesting living quarters.

The optimum temperature for body lice is about
87 F., and when this temperature increases, the lice
become agitated. This stimulates their activity so
that they tend to leave healthy persons heated by exer-
cise, or sick persons heated by fever. This tendency
of lice to pass from fever patients to healthy persons
is of importance in the spread of disease.

Circular 9 Lice

Two problems are encountered in the control
of human lice. The lice and eggs on the body must
be eradicated as well as those in the clothing and

An efficient control system includes preven-
tion of louse dissemination by not allowing individual
infestations. Once lice are established, disinfesta-
tion must be systematically undertaken. Treatment of
living quarters, individuals, and equipment should
be simultaneous. An efficient delousing plan involves
the treatment of a man for lice on his body, while
his clothing and equipment are disinfested nearby
and are ready for him after he has bathed, shaved,
and been deloused. Although lice are less prevalent
in the United States than in many parts of the world,
infestations are not infrequently encountered, and there-
fore systematic inspection, especially of new recruits,
is important to prevent the establishment and spread
of infestations in military units.

In the event that typhus or other louse-borne
diseases are suspected, doctors and nurses should
take adequate steps to prevent becoming infested.
This danger is increased by the fact that lice are
inclined to crawl away from patients with fever.
It is recommended that garments be provided designed
to exclude lice, including the use of rubber gloves
extending over the sleeves of gowns.

Head Lice

Treatment of hair.--Close clipping of the hair
facilitates head louse control, and many of the eggs
and lice are thus removed. However, clipping the hair
is not essential to control. Derris or cube powder
containing 3% rotenone (the insecticidal principle)
is effective when used as a dust or a wash.

Circular 9 Lice

The use of the material as a wash is more sat-
isfactory in general because it insures thorough
coverage. For this purpose is recommended a mix-
ture of 5 level tablespoonfuls of derris or cube pow-
der, 2 level tablespoonfuls of neutral soap, and
1 quart of warm water. The material is applied thor-
oughly to the hair and the surplus water taken up
with a towel without rubbing the hair dry. The
material should remain for at least 8 hours. In most
instances, a single treatment of this kind will destroy
all lice. The louse eggs, however, are not killed
by the insecticide being brought in contact with
them, and many people wash their heads soon after the
treatment, thus removing the derris and allowing the
nits to hatch. This necessitates a second applica-
tion about 10 days after the first.

When the dust treatment is used, a salt cellar
is very convenient for application. Place the proper
dose of powder in a clean salt cellar, then work
over the head, parting the hair with one hand and
shaking into the part a small quantity of powder.
Where the entire dose is applied, gently massage the
entire head with the fingers of both hands. A level
teaspoonful of powder is sufficient for a short-
haired person and should be left in the hair for
48 hours before being washed out.

Other treatments recommended are:

1. Equal parts of kerosene oil and olive
oil applied to the hair and scalp at night and washed
out the following morning with warm water and soap.

2. Equal parts of kerosene oil and vinegar.
Apply thoroughly to the head and cover with a towel
for half an hour; then wash the following morning.

Circular 9 Lice

3. A 10 percent solution of larkspur is
applied by means of a large towel, soaked and wrapped
like a turban around the head and kept on six or eight
hours overnight.

Eggs are not killed or removed by the insec-
ticides used to kill the lice; therefore it is nec-
essary to remove them with a fine-toothed comb. Hot
vinegar tends to loosen the cement fastening the
eggs to the hairs. Apply vinegar liberally to the
head and then wrap the head in a bath towel wrung out
of hot water and keep this on for an hour.

Treatment of hats.--Hats may be treated by
methods recommended for clothing under "body lice"
(p. 11).
Body Lice

Treatment of body.--Body treatment in the
case of body lice consists of thorough bathing in
warm water with liberal use of soap. Liquid soap
made in accordance with the following formula is
recommended: Boil 1 part of soap chips in 4 parts
of water, then add 2 parts of kerosene. This jel-
lies when cold. To use, take 1 part of this soap
jelly to 4 parts of warm water. Rub to a good lather
and leave lather on the body for 15 minutes before
washing off.

Finely ground derris or cube powder contain-
ing 2 or 3% rotenone is highly effective against
the lice in all stages except the egg. It should
be dusted lightly on the body, but more especially
on the seams of the clothing at points frequented
by the pests. The persistent use of this powder should
ultimately eliminate an infestation. The frequency
of application depends upon the exposure to infesta-
tion, frequency of bathing and changing clothing,
and whether the powder is found to irritate the par-
ticular individual. '?Yr


Circular 9 Lice

Those exposed to lice can secure much protec-
tion against becoming infested by dusting the body
and clothing with this material. A shaker can is
convenient for applying the powder.

If the derris or cube contains more than 3c
rotenone it should be diluted with talc.

A powder which has been widely used against
body lice is known as NCI. The formula follows:

Naphthalene 96%o
Creosote 2%
Iodoform 2%

This powder is sprinkled freely on the body and in
the clothing. It may be irritating and is not rec-
ommended for use around the pubic region.

Two other powders that have been recommended

(1) Talc 20 grams
Naphthalene 1/2 gram
lodoform 1/2 gram
Creosote 1 cc.

(2) Talc 20 grams
Sulphur 1/2 gram
Creosote 1 cc.

The former is said to be cheaper, drier, and less
irritating; the latter six times as effective as
NCI, less irritating and drier.

Treatment of clothing.--Clothing and equip-
ment are treated by several methods: dry heat, hot
water, steam, chemicals, fumigation, storage, or a
combination of methods.

Circular 9 Lice

Dry heat. Exposure to dry heat at 140 F.
for 20 minutes kills lice in all stages. Ovens or
chambers for this purpose may be so constructed that
clothes may be hung up and treated with the least
amount of damage or wrinkling. Some measure of con-
trol is effected by the ordinary ironing processes.
All stages of lice are killed in dry heat in 1 min-
ute at 159 F. Dry heat is recommended for leather,
felt, rubber, or webbing fabrics, but is considered
harmful to woolen materials.

Hot water. Hot water at 150 F. for 5 min-
utes is effective in killing all stages of lice.
Cotton, linens, or silks may be treated in this
manner, or they may be immersed in water at 212
F. for 1 minute. Leather, felt, rubber, or webbing
fabrics are damaged by hot water treatments. Woolens,
unless especially handled,are liable to undue shrink-
age. Pierce, Hutchison, and Moscowitz worked on this
problem in 1919 and recommended the usual laundry
processes, which follow:

"la. In the washer run a current of live
steam fifteen minutes, revolving cylinder every five
minutes, and discharging water of condensation every
five minutes. Remove the garments and shake until
almost dry. This requires only a few shakes.

"lb. Submerge in water at 1650 F. for twenty
minutes without motion, except a few revolutions
every five minutes.

"2. Wash 15 minutes at 131 F. in heavy suds
and light load.

"3. Rinse three times, three minutes each,
at 131 F.

"4. Extract.

Circular 9 Lice

"5. Run in tumbler fifteen minutes at a min-
imum of 1400 F.

"We advise live steam (la) or very hot soak-
ing (lb) only in cases where there is no heated
tumbler (5) available, or where the garments are
suspected of being contaminated with very resistant
spore-bearing bacteria.

"In other words, we recommend the usual laun-
dry methods for the disinfection and disinsection,
because of their added value of cleansing.

"There can be no doubt that the ordinary pro-
cesses of the laundry will kill all lice and their
eggs, and probably all insect life."

Steam. Live steam in a steam chamber at 259
F. for 10 minutes will kill eggs and active stages
of lice. When a barracks bag or roll of infested
clothing was exposed to steam under pressure, so
that a temperature of 167 F. was produced in the
center of the roll, all eggs and lice were killed.
Eggs are killed in moist heat in 10 seconds at
159 F.

Portable sterilizers and Serbian barrel-type
delousing units have been successfully used as steam

Leather, felt, rubber, and webbing materials
are damaged by steam, but woolens are little affected
and shrinkage is negligible when clothing is properly
handled. However, steam is said to fix certain
stains, such as bloodstains.

Chemicals. Cresol solutions have been recom-
mended for infested articles which may be damaged
by other methods. A 5 percent solution in water
may be used as a wash, or materials may be immersed
for 30 minutes in a 2 percent solution at 1000 F.

Circular 9 Lice

Fumigation. Fumigation is recommended for
killing all stages of body lice. Three materials
are commonly used:

1. Hydrocyanic acid gas. This is poisonous
and should be used with extreme care by experienced
operators. The standard dosage for lice is 1 lb.
of cyanide to 1,000 cu. ft. of space (see Cir. 22).

2. Carbon disulphide. Clothing may be deloused
by using carbon disulphide in a tight container such
as a chest or can. The carbon disulphide is put in
a shallow open pan on top of the loosely packed
clothing. As the liquid evaporates, the resulting
gas which is heavier than air flows downward into
all parts of the enclosed space. Use carbon disul-
phide at the rate of 1 pound to 1,000 cu. ft. of
space, and then keep the container tightly closed for
24 hours. Carbon disulphide is highly inflammable
dand exposive and no fire or open flame should be
-.. e n-used -
near __while gas inused (see Cir. 22).

3. Chloropicrin, one of the tear gases, is
extremely toxic to insects and also to man. The
irritation to man's eyes, nose, and throat, however,
is a warning of its presence. If used as directed,
chloropicrin is non-explosive and non-inflammable.
It is highly penetrating, but fumigated clothing may
be worn after an airing of 3 to 5 minutes. Chloro-
picrin will not injure leather goods, but will affect
rubber, and if used without impurities of chlorine
and nitrogen peroxide, will not bleach colored fab-
rics. Chloropicrin is used as a fumigant in the
same manner as carbon disulphide. It should be used
only by experienced operators. Heat is used to exped-
ite evaporation and penetration. This may be applied
to the fumigation chamber as a whole so that the tem-
perature is about 90 F. A convenient method of ap-
plying heat is by heating water in flasks, or by plac-
ing hot stones or bricks among the clothing in a chest.
One quart of water at 180 F. is required for each
cubic foot of space. At these temperatures lice and

Circular 9 Lice

eggs may be killed within thirty minutes with 1
ounce of liquid ohioropicrin used for each 7
cubic feet of space (see Cir. 22).
Storage. Lice can live without food for
10 days at a temperature of 400 F*; and at a tem-
perature of 85 7. they can live only 2 or 3 days.
To make sure that infested garments are free from
living lice they should be kept in storage for 30
days. This will destroy by starvation all active
lice placed in storage and give time for the eggs
to hatch and newly hatched larvae to die. Care
should be taken not to place additional infested
clothing with material already in storage, for
this would allow reinfestation.
Natural means. In the absence of equipment
for thorough delousing, exposure of clothing to
extreme heat or cold may be utilized in reducing
louse infestations. Spreading infested clothing
in the sun in hot climates will destroy all lice
in a few hours, and similar exposures to zero ternm-
peratures will do likewise. Another method of
reducing the number of body licoe by natural means
is to peoe infested garments to predacious ants,
such as fire ants.
h Treatment of infested uarterso.--Bedding
should given e same treatment as clothin,
or hung up out of doors for a period of 2 to3
weeks. Floors and walls, especially cracks
should be sprayed with 3 to 5 percent oresol, or
the infested building should be fumigated with
hydrocyanic acid as; the latter is the most effec-
tSve remedy and will also kill all other forms of
insect life which may be in the house. A revi-
ously mentioned, however, this is a veryrleailTy
Poison and in oases where its use is decided
% I IV is sell ToO lo a eZixer enold zuHiga-
tor t mazje Me aOplioation see oir. 22i.

Circular 9 Lice

Pubic Lice

Treatment of body.--Pubic, or "crab" lice,
may be destroyed with derris or cube powder or
ointment. The ointment is made by thoroughly mix-
ing 1 part by volume of derris or cube powder
(200 mesh, 4 to 5% rotenone) in 10 parts of petro-
latum. It is applied lightly to the affected

The use of the powder is more satisfactory
because it is so easily distributed by means of a
shaker can. A very light, but well distributed,
application repeated a second time after a lapse
of 10 days will eliminate an infestation. The
powder is slightly irritating to some people. It
may be washed off after remaining on overnight.

Light infestations in the eyelashes and eye-
brows can usually be dealt with by removing the
lice and eggs with a fine pair of forceps; however,
derris ointment can be used. Care must be taken
not to get this material in the eyes as it causes
irritation and swelling.

Mercurial ointment is often used on the in-
fested parts to kill crab lice. It is poisonous,
however, and should not be used too freely or over
too much of the body at one time.

Eggs may be removed by shaving the infested
portions or by softening the cement with which the
eggs are attached to the hairs with warm vinegar
and rubbing them off.

Treatment of clothing.--Clothing is not so
readily infested with pubic lice as with body lice.
Precautions should be taken, however, against
"stragglers" and dislodged hairs bearing lice and
eggs. Treatment of clothing should be carried out
as under section on body lice (p. 11).

Circular 9 Lice

Treatment of infested quarters.--Living
* quarters are not likely to become infested with
pubic lice. Bedding should be attended to the
same as clothing (p. 11) because it may become


Bacot, A. ------------ 1917 A Contribution to
the Bionomics of
Pediculus humanus
(ves timenti) and
Pediculus capitis.
Parasitology, v.
9, no. 2, pp.
Buxton, Patrick A. --- 1939 The Louse. Edward
Arnold & Co.,
London, 115 pp.
Dunn, Lawrence H. -- 1923 Bathing and Delous-
ing American
Troops at Brest,
France, Prior to
Their Embarkation
for the United
States. The Mil-
itary Surgeon,
pp. 1-7.
Foster, M. H. ------ 1918 Carbon Tetrachloride
Vapor as a Delous-
ing Agent. U. S.
Public Health
Reports, Reprint
489, pp. 1823-1827.
Hutchison, R. H. and 1919 -- Studies on the Dry
Pierce, W. D. Cleaning Process
as a Means of De-
stroying Body Lice.
Proceedings of the
Ent. Soc. of Washing-
ton, v. 21, no. 1,
pp. 8-20.

Circular 9 Lice

Hutchison, R. H. --- 1919 -- Experiments with
* Steam Disinfectors
in Destroying Lice
in Clothing.
0 Journal of Para-
sitology, v. VI,
pp. 65-78.
Moore, W. and -------- 1919 An Investigation
Hirschfelder, A. D. of the Louse
Problem. Research
Publications, Univ.
Minnesota, Minnea-
polis, v. 8, no. 4,
86 pp.
Nuttall, G. H. F. ---- 1917 The Biology of Pedicu-
lus humanus. Para-
sitology, v. O10,
no. 1, pp. 80-185.
Nuttall, G. H. F. 1918 The Biology of Phthirus
pubis. Parasitology,
v. no. 3, PP.
Nuttall, G. H. F. -- 1918 -- Combating Lousiness
Among Soldiers and
Civilians. Para-
sitology, v. 10,
no. 4, pp. 411-
Pierce, W. D. -------- 1921 Sanitary Entomology.
pp. 301-329.
SRichard G. Badger,
Pierce, W. D. and -- 1919 Government Report on
others Laundry Liachinery,
Its Adaptability
to Various Require-
ments of Disinfec-
tion and Disinsec-
tion. National
Laundry Journal,
Chicago, v. 81,
no. 1, pp. 4-14.

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