Industrial, institutional, structural, and public health pest training manual

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1981

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INDUSTRIAL, INSTITUTIONAL, STRUCTURAL, AND
PUBLIC HEALTH PEST TRAINING MANUAL

S7/.TE DOCUMENTS COLLECTS;’

FEB 0 1988

Montana state lib.t/.ry.

1515 E. 6th AVE.
HELENA, MONTANA 59S2C

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STATE OF MONTANA
DEPARTMENT OF AGRICULTURE
HELENA, MONTANA
JANUARY, 1931

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MONTANA STATE LIBRARY

S 628.96 A7iis 1981 C.1

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TABLE OF CONTENTS

Page

PREFACE

CHAPTER I - COMMUNITY PEST CONTROL

A. Introduction 1

B. Nuisance Arthropods 1

C. Fabric Insects 5

D. Mechanical Transmitters of Disease 6

E. Venomous and Biting Arthropods.- ... 9

F. Human Ectoparasites 12

G. Insect Pests of Stored Foods and Grains 14

H. PesticideUse inFood Plantsand FoodHandling Establishments . 17

1. Outdoor Area Food Establishment 20

2. Non-Food Areas 21

3. Food Storage Areas 22

4. Food Processing Areas 23

Pesticide Materials Registered For Use 24

I. Structural Pest Control 28

J. Animal Pests 30

CHAPTER II - MOSQUITOES AND THEIR CONTROL

A. Philosophy 36

B. Mosquito Biology 36

C. Classification of Mosquito Breeding Places 38

D. Mosquito Surveys 38

E. Methods of Control 40

F. Chemicals for Mosquito Control 43

PREFACE

This manual was prepared as a study guide for pesticide applicators
involved in community health pest control, and control of pests in busi-
nesses, institutions, food producing establishments, and homes. Discussions
of Montana pests that are most common in all of these situations are in-
cluded. This manual can be used to study for the examinations in Public
Health Pest Control, Food Manufacturing and Processing, Industrial, Insti-
tutional, Structural and Health Related and also Regulatory Mosquito
Abatement .

To simplify information, trade named products and equipment have been
mentioned. No endorsement is intended, nor is criticism implied of similar
products or equipment w7hich are not mentioned.

We wish to acknowledge the help of personnel of the Environmental
Management Division, Montana Department of Agriculture in preparing this
manual .

i

CHAPTER I

COMMUNITY PEST CONTROL

A. Introduction

This Chapter will deal with insects, and other arthropods, rodents,
birds and animal pests affecting man's health, structures, fabrics and
foods. The type of applications concerned with these pests include:
pest control applicators (PCA'S), institutional and public school per-
sonnel, public health sanitarians and related personnel.

B. Nuisance Arthropods

Ants - Class : Insecta Order: Hymenoptera Family: Formicidae

Ants are social insects consisting of workers (nonreproductive
females), reproductive females and reproductive males. Ants have a
narrow waist between the thorax and abdomen called the pedicel. Ants
are divided into two groups on the basis of a pedicel consisting of one
or two nodes. Ant groups are known either as "single-node" or "double-
nodes" .

Ants develop by complete metamorphosis. The worker ant is the
adult normally seen as a pest. Workers do the work for the colony such
as nest construction and gathering food. It is in gathering food they
become pests. Food preferences differ as to species but for the most
part ants are attracted to sweets, fats and proteins. Some species

like only one kind of food; others will eat several kinds. The

reproductive females are usually larger than the workers.

Ants which may be encountered in and around buildings include:

1. Field Ant (Formica spp) -single-node, may be brown, black, red,
or combination thereof and vary in size from 1/8 to 3/8 inches.
They prefer sweets but also feed on other insects. Nests are
commonly found along sidewalks, fences, and flower beds.

2. Adorous House Ant (Tapinoma sessile (Say) - Single-node, small

(1/8 inch) varying from dark brown to black. They frequently nest

in walls and underneath floors. When crushed these ants give off

an unpleasant odor. They prefer sweet foods such as sugar, syrup,
fruit juices, secretions of plants and honeydew from other insects

3. Pharaoh Ant (Monomorium pharaonis) - a tiny, two-node, yellowish-
red ant, 1/12 to~l/10 inch. This species generally nests around
fountains and in walls of buildings. They prefer sweets and
protein foods including syrups, fruit juice, cakes, greases, dead
insects and meat.

4. Small Honey Ant (Prenolepis imparis) - a tiny, single-node, shiny
black ant, 1/16 to 1/8 inch, is attracted to sweets.

1

5. Thief Ant (Solenopsis molesta)- a very small (1/16 inch) reddish,
yellowish or pale brown, shiny ant. Attracted to fatty foods,
such as bacon, other fatty meats and cheese but may feed on sweets
at times. Their name results from the frequent practice of living
in nests of larger ants, feeding on the larvae.

Suggested Control Methods

The best method for control of ants is to locate the nest and
treat them directly. It is often difficult to locate the ant nest
if the colonies are situated in walls, under pavement, in stone
cracks or other secluded places. To prevent ants from entering a
building, spray insecticide on the outside walls from the ground
up to the windows; or the foundation and adjacent four inches of
soil; under porches; around doors and windows; and in cracks and
perimeters of cement walk ways. Ants indoors can be controlled
by treating base boards, moldings, around plumbing and heating
pipes, around sinks and bathtubs and in kitchen cupboards. Com-
mercial bait formulations (such as Kepone) may be effective.

Workers will carry the bait back to the nests where it is fed to
larvae and reproductives . However, baits may be ignored because
of more attractive foods.

Silverfish and Firebrats - Class: Insecta Order: Thysanura
Family: Lepismatidae

Silverfish and firebrats (also called "bristletails",
because of the three slender appendages at the rear of their bodies)
are about 1/2 inch long. Silverfish are distinguished from fire-
brats by their shorter appendages and antennae and their uniform
silver to brown color. Firebrats are a mottled grayish brown.
Silverfish prefer 70 to 80 degree temperatures, whereas firebrats
prefer temperatures 90° or higher. Both like moist locations.

Both feed on starches and proteins and can damage fabrics, paper,
books, and furnishings.

Applications of residual insecticide sprays or dusters should
be in and around heaters, warm pipes, storage areas, along floor-
wall junctures, cracks and crevices in basements and other hiding
places. Damp areas under building should be treated.

Springtail s - Class: Insecta Order: Collembola

Springtails are small, usually less than two millimeters,
vary from white to gray and are without wings. A forked appendage
attached to the lower side of the abdomen can be released suddenly
causing the springtail to leap into the air, hense his name.
Springtails are usually found in damp places around plumbing, in
kitchens, in bathroom and around window jams. They do not cause
damage but are a nuisance when in large numbers.

Elimination of damp places through construction or ventilation
are good control measures. In the home trash piles should be
removed and compost piles located away from the building.

2

Dusts or emulsions should be used if chemicals are believed to
be needed since oil won't adhere to the damp surfaces. Bathroom
overflow drains, water pipes and other moist surfaces where
springtails can be seen should be treated; outside granular
treatment of Sevin and Malathion is effective.

Earwigs - Class: Insecta Order: Dermaptera

Although earwigs cause great concern because of their appear-
ance, they are harmless to humans. The pinchers of larger
earwigs may cause painful pinch to humans.

The European earwig (Forf icula auricularia) is the common
earwig in most areas of the United States. It is dark reddish-
brown and is about 1/2 to one inch in size. Earwigs develop by
simple metamorphosis. Although they have wings, they are relatively
poor fliers and rarely fly.

Earwigs are active at night and usually hide during the day.
Earwigs prefer moist hiding places such as under debris, boxes,
and similar materials. Good yard sanitation, particularly near
the building, and good housekeeping inside, such as in basements,
has much to do with effective control. Well maintained structures,
including tight windows and sealed foundations, are important to
preventing earwigs from entering buildings.

Chemical control of earwigs in buildings must include control
outside of buildings. Commercially prepared baits in plant beds
around the building provides control in these areas, reducing
the numbers which might enter the building and preventing damage
to the plants. Application of sprays or dusts outside and along
floor-wall junctures or other hiding places inside buildings
will give effective control. Dusts and sprays such as Chlordane
should be applied in the opening soon after the young earwigs
come out of the soil .

Crickets - Class: Insecta Order: Orthoptera Family: Gryllidae

Both the field and the house cricket will enter buildings.

They can be a nuisance and damage fabrics. Crickets develop by
simple metamorphosis. The field cricket is larger than the house
cricket. Its wings extend beyond the wing covers. The house
cricket remains hidden during the day. It will eat or drink most
anything and thus may damage clothes, paper, fruits and vegetables.
Chemical control of crickets usually involves application of
residual insecticides to foundations, window wells, damp areas
in basements and potential hiding places.

Centipedes - Class: Chilopoda

Centipedes have a flattened worm-like body with head and
abdominal regions. Centipedes vary from brown to grayish-yellow
to green and they may have as many as one-hundred pairs of legs,

3

one pair to each body segment. The appendages of the first
body segment behind the head are clawlike and function as poison
jaws. In reality, they are modified legs.

Centipedes other than the house centipede, live outdoors in
moist areas under leaves, stones and trash. They often enter
buildings at night and can be found most any place providing cover.

The house centipede may live in damp areas of a building.

They feed on small insects, their larvae, and on spiders. Since
they are beneficial, control is not necessarily desirable. If
present in large numbers, building occupants may feel that control
is mandatory. Chemicals may be applied outdoors to their hiding
places. Diazinon, Sevin, Chlordane , and Dylox are often
recommended for control. Indoors, centipedes may be controlled
with a vacuum.

Millipedes - Class: Diplopoda

Millipedes are worm-like in appearance and are 1/2 to three
inches in size. They have short antennae and two pair of legs on
most abdominal segments.

Millipedes live in moist, decaying material. Their diet
consists of decaying organic matter and green leaves. They usually
do not damage plants or lawns nor do they damage food supplies or
structures. Millipedes do not bite or sting humans. For this
reason, control is seldom required.

Millipedes may enter buildings but are not a problem if
harborages are removed from around a building. An application of
a residual insecticide, if necessary, around the foundation of
the building should give adequate control .

Sowbugs and Pillbugs - Class: Crustacea Order: Isopoda

Sowbugs and pillbugs are segmented, oval, brown or grayish
in color and about 1/2 inch long. Sowbugs have tail-like append-
ages but pillbugs do not. Pillbugs also roll up into a ball
when threatened.

Sowbugs and pillbugs feed primarily on decaying organic material
and are normally found outdoors but migrate indoors occasionally.
They require moist conditions and are most active at night. Outside
they will be found under rocks, debris and decaying vegetation.
Inside they will seek crevices such as in basement floors.

Removal of decaying vegetation from around the foundation of
a building and dry basements are deterants to sowbugs and pillbugs
and should be adequate for control . If they are present in
basements, residual insecticide dusts or sprays may be applied
around floor drains, in floor crevices, or other floor openings or
voids at or near grade level. Outside treatments should be made

4

to and near foundation walks, around and beneath door steps and
porches, subfloor crawl spaces and damp areas immediately around
the structure.

Clover Mites - Class: Arachnida Order: Acari Family: Tetranychidae

Clover mites are reddish-brown and about the size of a printed
period. They are not a public health hazard but can be a
nuisance inside buildings. They are normally associated with
healthy lawns (particularly new lawns) and well fertilized old
lawns. They migrate into buildings through openings around
windows when weather is favorable. This is particularly true in
the spring and in the fall since they are relatively inactive
during very hot or cold weather. They migrate from lawns because
of population pressures or because of unfavorable lawn conditions.
They frequently overwinter in outside building walls.

A two foot bare soil barrier around a building helps to prevent
clover mites from reaching the outside walls. Many varieties of
flowers and shrubs can be planted in these soil barriers. App-
lication of an oil-base insecticide to the outside foundation is
effective. If mites are already on the wall, then application
of the same type of insecticide around the window helps to
prevent entrance into the building. If the mites have entered
the building, wiping off surfaces with a detergent-disinfectant
solution is effective and is recommended over the application of
insecticides .

C. Fabric Insects

There are many insects capable of damaging fabrics. Only those
insects which feed on fabrics and specifically the protein "keratin"
are included in this guide. Keratin, a major constituent of animal
hair, horns, hoofs and feathers is digestable by only a few insects
(primarily fabric insects). Fabric insects also need vitamins and amino
acids normally found on contaminated fabrics. Such contamination is
inevitable through handling and thus contamination is always sufficient
to support fabric pests.

The two groups of fabric pests are moths (Order: Lepidoptera,

Family: Tineidae) , and beetles (Order: Coleoptera, Family:Dermestidae) .

Clothes Moths

There are three moths which are called clothes moths: the webbing
clothes moth (Tineola bissel 1 iel la) , the casemaking clothes moth
(Tinea pellionella) and the tapestry moth (Trichopaga tapetzella) . The
most common moth in northern states is the webbing clothes moth.

The body and wings of the webbing clothes moth are uniformly buff
colored. The wings when extended measure less than 1/2 inch. The
larvae, which causes the damage, are a creamy-white and about 1/2 inch
long. Although the larvae feed primarily on fabrics made of animal
products, they will at times incidentally damage other fabrics while
feeding on their natural food.

5

Fabric Beetles

The most common fabric beetles are the black carpet beetles
(Attogenus piceus) , the varied carpet beetle (Anthrenus verbasci) , the
common carpet beetle (Anthrenus scrophulariae) and the furniture carpet
beetle (Anthrenus flavipes) . Adult carpet beetles can be seen in
windows in the spring or early summer if an infestation exists in a
building .

The adult black carpet beetle is oval, dark brown to black and
1/8 to 3/16 inches long. The larvae are carrot-shaped, grow up to 1/2
inch in length and are shiny brown to black, with long tail bristles
resembling a paint brush. Larvae prefer temperatures around 80°F.
and a high relative humidity but may exist in a wide environmental
range. Larvae shy from light and are commonly found in closets, under
basemolding or in furniture. Larva food consists of protein containing
substances including animal products and cereals.

The varied carpet beetle adults are about 1/8 inch long, slightly
oval shaped and mottled with white, brownish and yellowish scales on
the back. Larvae are about 1/4 inch long with three dense tufts at
the rear. Food of the larvae consists of animal fabrics and almost any
plant or animal food. Larval skins and feces can be found near feeding
locations .

The adult common carpet beetle is about 1/8 inch long, oval shaped,
gray to black in color with orange scales down the middle of the back.
Larvae are not more than 1/4 inch long, are reddish-brown in color and
covered with black and brown hairs. Larvae feed on wool carpets and
other materials of animal origin.

The furniture carpet beetle adults are more rounded and slightly
larger than the varied carpet beetle. They are black with mottling of
yellow and white scales. The larvae have an elongated oval shape and
are covered with brown hairs. The larvae often attack upholstered
furniture, feeding on fibers of animal origin and fibers contaminated
with animal excreta.

Control of Fabric Insects

The prevention of fabric damage from these insects by use of
Paradichlorobenzene or Naphtalene (moth balls or crystals) is a common
and effective practice. Good housekeeping practices such as vacuuming
basemoldings and edges of carpets, good cleaning and storage practices
with clothing, and storage of cereals in covered containers help
prevent damage as well as control fabric insects. Chemical control
measures involve application of residual insecticides, with wetting
agents, to the edges of carpets, to other carpet areas not subject to
traffic, to areas around heating units, baseboards and to the bottom
of furniture.

D. Mechanical Transmitters of Disease

6

Domestic Flies

Flies belong to the Class Insecta and to the Order Diptera. The
flies ordinarily considered to be "domestic" belong to the Families
Muscidae (housefly and related species) and Calliphoridae (bottle flies
and blowflies). All flies undergo complete metamorphosis.

The above families have been associated with mechanical transmission
of some human diseases. Mechanical transmission involves the trans-
porting of organisms associated with plant and animal wastes on the body
of flies to surfaces which come in contact with food or the mouth.

Domestic flies reproduce as well as feed on or in plant and animal wastes.

Members of the Family Muscidae lay their eggs on such organic matter
as animal manure, human excrement and garbage. Adult flies are attracted
to a large variety of food materials. This group of flies increases
the possibility of disease transmission through their need to ingest only
liquid materials. In liquidizing solid foods by means of regurgitated
saliva, they may transfer organisms acquired from filth to clean food.

Bottle flies and blowflies feed and reproduce in animal and plant
wastes (primarily animal wastes). These flies are particularly abundant
in populated areas near meat processing plants and garbage dumps. Eggs
are usually laid on meat or dead animals but are also laid on decaying
vegetable matter. Adults are usually large flies with a metallic blue
or green color.

The most effective and principle control measure of domestic flies
is good premise and community sanitation. Good sanitation eliminates
or isolates wastes and thus prevents access to reproductive sites.
Screening of buildings to prevent fly entrance, storing garbage in
fly-tight containers, twice a week garbage collection, landfill disposal
of refuse and sanitary disposal of other community organic wastes are
all important sanitation measures.

When breeding areas are not eliminated, it becomes necessary to
chemically control adult flies. Baits are sometimes very effective,
particularly when placed around garbage storage areas. The most effect-
ive chemical control is the application of residual surface sprays to
garbage storage areas inside a building.

Misting or fogging with an insecticide of low toxicity may be
necessary for severe infestations.

Domestic Cockroaches

Cockroaches belong to the Class Insecta, to the Order Orthoptera
and to the Family Blattidae. Roaches develop by simple metamorphosis.
The female produces a purse-shaped egg case, called an ootheca,
containing two rows of eggs. The oothecae can be used for species
identification .

7

Roaches usually prefer a warm, moist environment. They are nocturnal
and thus are not seen in daylight unless the population is large. Those
which live in buildings are scavengers and feed on a wide variety of
foods. They give off odorous secretions causing off flavor in foods.

When populations are large the secretions cause an odor in the area of
infestation.

Although cockroaches at one time were major transmitters of gastro-
enteritis, particularly salmonellosis, the incidence of those diseases
have been reduced by controlling roaches by sanitary and chemical methods.
Roaches remain a potential for transmitting enteric illness through food.

Three species of cockroaches are commonly found in Montana: the
German (Blattella germanica) , the American (Periplaneta americana) ,
and the Brown-banded (Supella supellectilium) .

The German roach is the most common. Adults are about 1/2 inch in
length and are light brown with two dark longitudinal stripes on the
upper surface of the first thoracic segment (pronotum) . Both sexes have
wings but rarely fly. The female carries the egg capsule protruding
from her abdomen until the eggs are ready to hatch. This character-
istic enhances reproductive potential. German roaches are carried from
place to place on or in food packages and cases, and may move from one
location to another. They are found in dark, warm moist locations near
water and food. Thus, hiding places in kitchens are ideal locations
for German roaches.

The American roach is reddish-brown and grows to about one and one-
half inches in length. Both male and female are winged. The male is
more apt to fly or glide. The American roach also prefers warm, moist
locations and may be found in food establishment basements.

The Brown-banded cockroach is 1/2 inch or shorter, is light brown
with light colored transverse stripes across the base of the wings and
abdomen. They are very active insects. Both male and female have
wings and the male flies readily when disturbed. They prefer warmer
and drier places than the German roaches. Brown-banded roaches are
difficult to control because they are found throughout a building; in
furniture, along picture moldings, in pantries and in closets. The
female leaves her egg capsules in furniture allowing infestations to
be transferred when furniture is moved.

Because cockroaches require water, food and a place to hide, envir-
onmental sanitation which makes these needs unavailable to roaches
provides basic control. Environmental sanitation practices include:
frequent disposal of garbage, storage of garbage in vermin-proof
containers, storage of food in protective containers, maintaining water
and sewer lines in good repair, proper building maintenance, housekeeping,
and construction which precludes hiding places for roaches. Once a
roach infestation has been established, good sanitation and chemical
methods must be combined to give complete control.

Application of a residual insecticide spray to all potential hiding
places is needed. These include behind appliances, in cracks and

8

crevices, under sinks, basemoldings, under furniture, in closets, in
cabinets and any place which is warm and moist. Application of dusts
with synetetic pyrethrum to difficult to treat areas (wall voids,
behind built in ranges, etc.) and the placement of baits at suspected
points of entry in combination with residual sprays provides effective
control .

E . Venomous and Biting Arthropods

Spiders - Class: Arachnida Order: Araneae

There are many species of spiders. Two of primary concern because
of their bites are; the blackwidow (Latrodectus mactans) and the
brown recluse (Loxosceles reclusa). Neither of "these spiders are
aggressive and tend to retreat when disturbed. They may bite when
threatened. Bites occur when a human and a spider attempt to occupy
the same space. This occurs when people put on clothes in which the
spider is hiding or when they roll onto the spider in a bed. People
should be cautioned against putting on clothing that have been hanging
for sometime in areas where spiders frequent without first checking
them. Beds and bedding should also be checked if spiders are prevalent.

The female black widow has a shiny black body about 5/8 inch long
with a red "hour-glass" on the underside of the abdomen. The male is
smaller, lighter colored and usually has a red or yellow mark on the
upper side of the abdomen. Webs can be found under buildings, in
corners of basements, under furniture or other shaded areas which are
resting places for insects. When the web is jarred, the black widow
will rush out and sting that which causes the vibration.

Localized pain, often spreading throughout the body and limbs may
result from a black widow bite. The reaction usually isn't fatal
unless a person is particularly sensitive. Treatment by a physician is
recommended .

The body of the brown recluse is about 1/2 inch long, light brown
in color, with a fiddle-shaped area on the cephalothorax (joined head
and thorax). Pain from the brown recluse bite may be immediate or
delayed several hours. Usually after a few hours the pain becomes
quite intense. Over a period of a few days the bite area becomes
blistered, then swollen and red, developing into an ulcerous sore, with
a final sloughing of dead tissues, resulting in a sunken scar. Treat-
ment immediately after the bite by a physician is recommended.

Chemical control has its place in spider control but it is usually
not as effective as environmental control. Besides the personal
precautions mentioned earlier, prevention of human contact involves
discouraging the presence of spiders in and around buildings. Control
of other insects through good premise sanitation, general house cleaning
and exclusion will reduce or eliminate the food supply for spiders and
thus create an unsuitable habitat. Webs should be removed and the
spider destroyed possibly with the use of a contact spray, such as
(Chlordane , Lindane or Diazinon) . Residual insecticide treatment outdoors
to cracked, crevices, corners and surfaces where webs are built may be
effective. Indoors the use of Paradichlorbenzene or similar materials

9

in storage areas for clothing and bedding will exclude spiders from
these areas.

Stinging Hymenoptera

The order Hymenoptera includes bees, wasps, ants, sawflies, para-
site wasps, and others. Most Hymenoptera are beneficial to humans
but some groups live in close proximity to humans and can be hazardous.
These latter groups are called the stinging Hymenoptera and include
the bees, wasps and yellow jackets. The hazard to humans is the venom
(protein material) injected by these species. Some people are
extremely sensitive to such material may have severe allergic as well
as toxic reactions. Persons in this category need immediate care and
should be prepared for such emergencies. The Allergy Foundation of
America recommends a kit for such persons containing prescriptions
from their physicians.

Members of the Family Vespidae (paper wasps) are probably the
severest stingers of the Hymenoptera. Most species of this Family are
banded with yellow and black or brown bands on the abdomen. This family
includes the genus Vespula (yellowjackets and hornets) and the genus
Polistes (single comb wasps). Vespids are large wasps (1/2 to one
inch long) . Impregnated queens formed late in the season over winter
and start a colony the following spring. Once a colony is started,
workers take over duties of nest building and gathering food, and the
queen devotes full time to egg laying. The nests are of paper, made
first by the queen then by the workers from plant fiber, rotten wood,
etc. Queens of yelowjackets and hornets over winter in the ground,
under bark of trees, or sometimes in buildings.

Most species of yelowjackets build nests in the ground but some
build nests in trees, shrubs or in the eaves of houses. Hornets build
the well-known hanging grayish-brown structure with a size and shape
somewhat like a football. The Polistes wasps build simple, single layer
nests under horizontal surfaces, such as under eaves and window ledges.
Polistes are distinguished from the Vespula by having a more constricted
waist and a slimmer abdomen.

Mud daubers, (Family Sphecidae) recognized by the narrow "waist",
construct their nests of mud, often in attics of old buildings. The
danger of being stung by mud daubers is not as great as with the
Vespidae .

Some species of bees, including honey bees, can be pests around
residences if they establish a nest in the area. As a rule, bees do
not ordinarily present a structural pest problem as do the wasps. When
honey bees establish their nests in buildings they are best removed by
a beekeeper.

There are several approaches to vespid control. (1) If possible,
locate nests and then apply insecticide dusts (such as Chlordane,
Lindane) directly into nests when it is dark. Cover ground nests with
dirt after treatment. Follow up succeeding nights until all wasps are

10

dead. Entry areas should be kept well treated. Persons allergic to
the sting should not attempt control; protective clothing should be
worn. (2) Place a bait consisting of a fish product and insecticide
in cages scattered throughout an infested area. Cages should have a
1/4 inch mesh screen to keep out birds, animals and children. (3)
Cleaning of outside garbage containers reduces their attraction.

After garbage containers have been cleaned application of 0.75% DDVP
to the inner surface garbage containers may be made.

Bedbugs - Order: Hemiptera Family: Cimicideae

The food of bedbugs is blood. There are several known to bite
humans but it is human bedbug, Cimex lectularius , which lives close
to humans and feed on their blood. Other species feed on bats, swallows
and other birds. Species which feed on bats and swallows may become a
problem for humans if bats or swallows make their home in buildings
used by humans (bat bugs may switch to human hosts if bats are excluded
or when bats move to their winter colonies). The human bedbug is about
1/4 inch long, wingless, flat, and reddish-brown in color. Its glands
produce a characterictic odor similar to almond. Eggs are attached to
most any available surface, even to the host. Growth is by single
metamorphosis. Nymphs as well as adults feed on blood. Adults can
survive a year or longer without food. The time period is somewhat
shorter for nymphs. Humans are a preferred host but they will also feed
on household pets and on rats and mice. Bedbugs are not known to
transmit diseases.

Although building construction, housekeeping and personal hygiene
can have some effect on bedbug control, chemical control is the only
positive control measure. A single application of a residual insect-
cide to mattresses, bed parts and cracks and crevices in wall surfaces
is standard chemical control procedure. Sprays containing Trichlorofon
(0.1%), Ronnel (1%), or Malathion (0.5 to 1.0%) are commonly used.
Special care should be exercised in the treatment of mattresses and
upholstery; only a light application should be made and under no cir-
cumstances should mattresses be soaked with spray. Infant bedding,
including the crib, should not be treated. Spray only tufts and seams
of mattresses and air dry at least 4 to 8 hours before reuse. If the
infestation persists, treat again at not less than two week intervals.
Fogging or misting of a room with synergized pyrethrum may be used to
speed control or to aid in the effectiveness of residual control.

Modified from: Public Health Pesticides, 1973, Center for

Disease Control, Public Health Service, Health Services and
Mental Health Administration, U.S. Department of Health, Education
and Welfare, Savannah, Georgia 31402.

Conenose Bugs - Order: Hemiptera Family: Reduviidae

This group includes the kissing bugs and assassin bugs. Most of
the Reduviidae feed on insects but a few feed on humans by sucking
blood. The bite of the conenose is painful. Some species have known
to transmit Chages Disease. Conenose bugs live in warm climates but

11

may be transported north. They are similar in appearance to squash
bugs. The conenose bugs, common in Southwestern United States, are
brown to black and measure about 3/4 inch in length.

Ticks - Order: Acarina Suborder: Lxodides

Ticks are arachnids. Although the order Acarina includes both
mites and ticks, because of their size, ticks are the most conspicuous.
All ticks feed on the blood of vertebrates. Most species belong to
two families; the Ixodidae (the hard tick) and the Argasidae (the soft
ticks). Although members of both families will bite humans, certain
species of hard ticks are the ticks usually associated with humans.

Some species in addition to being biting pests, transmit Colorado
tick fever and Rocky Mountain spotted fever, from which there is full
recovery if the tick is removed in time. Tick paralysis most often
observed in children under seven years old, has a high fatality rate.

The body of ticks, prior to feeding, is flattened and tapered
toward the head. After feeding, the tick, particularly the female,
becomes greatly distended. The ticks leathery body covering (cuticle)
is capable of considerable distension.

Ticks have four stages in their life cycle: egg, "seedtick"
(intermediate larval stage), nymph and adult. The seedtick has six
legs and feed on small vertebrates, particularly rodents. The nymphs
have eight legs like the adults and usually feed on small animals. The
adults, who feed to reproduce, normally feed on large animals including
humans. Most hard ticks do not dwell in nests but wait on vegetation
and drop on passing hosts. This is particularly true of the Rocky
Mountain wood tick which transmits spotted fever. The dog tick on the
other hand, may be brought to humans by their pet. Soft ticks are
almost always associated with the nests of their immediate host and for
this reason humans are less likely to come into contact with them.

Removal of an attached tick is usually the most immediate control
measure. A slow steady pull should remove the tick without breaking off
the mouth parts. Application of alcohol, vaseline, or fingernail polish
will help remove the tick. An antiseptic should be applied to the
bite wound and the persons hand should be washed after the tick has
been removed.

Other important control measures include avoidance of tick infested
areas, wearing protective clothing, clearing of brush and weeds around
homes and recreation areas, and well-kept yards. When ticks are
brought into homes it may be necessary to use chemical control. Appli-
cation of residual insecticide along basemoldings , floor and wall
crevices and similar hiding places is recommended.

F. Human Ectoparasites

Human Lice - Order: Anoplura

There are three kinds of human lice: the body louse (Pediculus

12

humanu s humanus) , the head louse (Pediculus humanus capitus) and the
crab louse (Phthirus pubis) . All three kinds are found in close
association with humans and depend on human blood for sustenance.

The control of body lice involves personal hygiene and sanitation.

It is these lice that can be involved in the transmission of three
human diseases: typhus, trench fever, and relapsing fever. Infestations
of body lice may be transferred from infested persons to others through
bedding or clothing or personal contact. Lice will normally die if the
infested bedding or clothing is not used for several days. Laundering
with hot water will destroy all stages of lice. Dry cleaning will
destroy lice on clothing or bedding which cannot be laundered. The
control of head lice usually involves shampooing the hair with a shampoo
insecticide which is prescribed by a physician. Control may also
involve lightly spraying upholstered chairs and couches with an approved
insecticide. Cleaning brushes, combs, and articles of apparel that
contact the head and neck are necessary.

The control of crab lice (which are spread chiefly by sexual
contact) involve washing the infested area with a shampoo containing
insecticide .

Fleas - Order: Siphonaptera Family: Pulicidae

There are five fleas which are known to bite humans and which can
be a problem in northern states: the human flea (Pulex irritans) , the
dog flea (Ctenocephalides canis) , the cat flea (C. felis) , the Oriental
rat flea (Xenopsylla cheopis) , and the northern rat flea (Nosopsyllus
fasciatus) . The preferred host of each flea is indicated by their common
names. However all of them will bite humans if provided the opportunity.
Humans may become infected when playing with pets. The dog and cat fleas
and the Oriental rat flea can be sources of disease to humans as well
as being a pest. The dog and cat fleas are known to transmit tapeworms
to their hosts. The Oriental rat flea is known to transmit bubonic
plague and murine typhus and is most common in coastal regions. Humans
are incidental hosts of cat and dog fleas. In the absence of the cat
and dogs, fleas will more readily attack humans.

Control of fleas on pets should be according to the recommendation
of a veterinarian. Likewise, a physician should be consulted if a human
flea infestation is suspected. Control of rat fleas must be coordinated
with the control of rodents and will be discussed under rodent control.

Control of fleas involves the premises as well as the host. Good
housekeeping practices are very important. Infestations on dogs and
cats will be concentrated in their sleeping places. Infested bedding
should be laundered or destroyed. Floor-wall junctures should be
vacuumed. Application of an insecticide in areas frequented by pets
should be correlated with flea control measures on the pets.

Control of human flea infestations should include laundering or
dry cleaning of bedding, vacuuming of upholtered furniture and
application of an insecticide to upholstered furniture.

13

G. Insect Pests of Stored Foods and Grains

General

There are a wide range of pests which cause damage to stored
products. Stored food insects feed primarily on such items as dried
fruits, grain, cereal products, flour, and nuts. Candy and cheese
may also be involved. Discussion here will involve those pests found
in mills, elevators, warehouses, processing plants, homes, and retail
stores .

Most insects involved with stored products require a warm environ-
ment for reproduction. Most do not lay eggs below temperatures of
60°F to 65°F. Almost all stored food insects are adopted to living
on food with a low moisture content.

Insects attacking stored grain include many of the same species
attacking these products stored under processed conditions. Their
populations are dependent upon; (1) numbers present in the bin before
harvest, (2) temperature of grain going into storage, (3) length of
time grain retains heat after going into storage (weather influence) .
(4) moisture content of the grain. To prevent high moisture spots,
grain from the field must be less than 13 percent of saturation and
the bin must be made tight against rain and snow. When grain retains
summer heat in storage, some stored grain insects may produce a new
generation in a month or less.

Insect Types Found in Stored Products

Common insects found in stored product situations can be separated
into four groups according to feeding habits: internal feeders,
external feeders, scavengers, and miscellaneous pests.

1. Internal Feeders

The larvae of internal feeders feed entirely within grain
kernels. Examples are the rice weevil, the granary weevil and
the Angoumois moth. Weevils belong to the Order Coleoptera
and to the Family Curcul ionidae . The Angoumois grain moth belongs
to the Order Lepidoptera and the Family Gelechiidae.

Adult rice weevils, considered to be the most destructive pest
of stored grain, are reddish-brown and 1/8 inch long. They infest
grain in the field as well as in storage. Larvae are short, stout,
with a whitish body and a tan head. Both adults and larvae feed
on a wide variety of grains. Infestation of grains can be detected
through staining which reveals the gelatinous egg plugs, not
visible to the naked eye. Although infestations are usually
confined to whole grain, they can be found in solidified milled
products such as macaroni or caked flour.

Adult granary weevils resemble the rice weevil but are dark
brown to black in color. Since they have no wings they are trans-
ported by humans through food supplies. Although reproduction

14

involves stored grain, not field grain, their life style is much
the same as the rice weevil. The adults hibernate in cold
weather.

Eggs of the Angoumois grain moth are laid on or near grain.

The larvae bore into the grain kernels and feed within, leaving
a thin layer of outer seed coat intact. These moths are
frequently found in homes, warehouses and stores. The adults are
yellowish-white and are about the size of clothes moths (1/2 inch
wing span). The larvae are minute and white.

2. External Feeders

Insects which feed through the outer coat of a grain kernal
into the kernal are called external feeders. Examples are the
drug store beetle, the tobacco beetle, cadelle beetle and the
Indian meal moth. The beetles belong to the Order Coleoptera.

The drug store and tobacco beetles belong to the Family Anobiidae
and the cadelle beetle belongs to the Family Ostomatidae. The
Indian meal moth belongs to the Order Lepidoptera and the Family
Phycitidae .

The drug store beetle feeds on flour, dry cereals, red pepper
and other dry foods. The adult is brown, 1/10 inch long and
cylindrical. The larvae are white and about 1/4 inch long.

I he tobacco beetle, besides being an important pest of stored
tobacco, is found in spices, dried plants, seeds and rice. The
adults are light brown and about two to three millimeters long.
The adults fly readily. The larvae are white with light brown
markings on the head.

The adult cadelle is shiny black and about 1/3 inch long.

The larvae are almost 5/8 inches long, dirty white with a dark
brown head. The larval prothorax (just behind the head) has a
dark-brown hardened plate covering. This beetle is commonly
found in packaged cereals, nuts, spices and fruits but is very
common in grain storage and flour mills. Eggs are deposited in
crevices of food materials. The larvae feed on the above foods
and tobacco. They usually only eat the germ portion of grains
and thus not only have the potential of damaging large numbers
of kernels but also provide entry for other insects.

The adult Indian meal moth has a wing spread about 3/4 inch.
The front wings are tan in front and reddish-brown in back. In
the home they are often mistaken for clothes moths. The larva
is about 1/2 inch long witli a dirty white color, sometimes with
a green or pink tint. The larvae feed on almost any dried food.

3 . Scavengers

Examples of the scavengers are the saw-toothed grain beetle,
the confused flour beetle, the red flour beetle, and the
Mediterranean flour moth. Scavangers feed on grain which has the
seed coat broken, either by another insect or by mechanical

15

damage. These beetles are also able to work their way into
packaged foods.

The adult saw-toothed grain beetle (Family Cucujidae) is
brown and about 1/10 inch long, with six saw-like projections
on the thorax. The larva is less than 1/2 inch long and has a
narrow body with a dirty white color. Eggs are usually laid in
crevices or in a food supply such as flour. This beetle is
found in dry cereals, dried fruits, dried meat and other dry
foods. The adults are small enough to penetrate into packaged
foods. The larvae eat finely divided food particles hence
this beetle is often found with other grain insects or in spilled
flour .

The adult confused flour beetle (Family Tenebrionidae) is
reddish-brown, and about three and one-half millimeters long.

Like the saw-toothed beetle, it is able to work its way into
packaged foods. It is an important pest in flour but may be
found in a variety of dried foods. The larvae are about 1/4 inch
long and yellowish-white.

The red flour beetle is similar in appearance and habits to
the confused flour beetle. It belongs to the same family. They
are strong fliers which may explain why they are frequently found
in stored grain.

The adult Mediterranean flour moth has a wing span of about
one inch. The pale gray wings have wavy black lines across them.
It infests most dried foods. Females lay eggs in flour or other
milled products. The larvae are white or pink, with a few black
spots on the body. Mats of silken threads left by the larvae
are good indications of infestations.

4. Miscellaneous Pests

Frequent pests of stored food include the meal worms (Order
Coleoptera, Family Tenebrionidae); the spider beetles (Family
Ptinidae); the psocids (Order Psocoptera); and grain mites
(Class Arachnida, Order Acarina) . These insects are often found
in stored products, but only occasionally in sufficient numbers
to warrant control .

Prevention and Control of Stored Food Infestations

Food housekeeping practices are very important in the prevention
and control of stored food infestations. Such practices include clean
storage facilities, cool storage conditions, storage of packaged foods
the floor and away from walls, and limiting storage time for
foods through rotation. Grain bins should be kept clean of debris both
inside and in the area outside around the bin. Bins may be sprayed with
insecticides such as Malathion , or Diazinon two or three weeks before
harvest.

16

When an infestation is detected, the first step in control is to
locate the source of the infestation. Once located, remove and destroy
the source and all infested materials. Thoroughly clean and remove all
loose materials from the premises. Vacuuming cracks and crevices and
scrubbing of floor and wall surfaces with a detergent -disinfectant
solution may be as effective as an insecticide. The application of
contact, residual or space spray insecticides may be desirable following
sanitation practices. It is essential that insecticides, whether
space sprays or residuals, be kept from contacting food. Care must be
used in application of insecticides. NO INSECTICIDE SHOULD BE CONSIDERED
"NONTOXIC" AND THUS SUITABLE FOR USE ON FOOD. All food stuffs must be
removed before treatment and all food contact surfaces covered and/or
washed after treatment. (Refer to Chapter 27 Part H for use of
pesticides in food establishments and food processing plants.)

Pest control in grain storage areas may involve the application of
insecticides like Malathion, or Pyrethrin, plus a synergist, as the
grain is going into storage for protection against insect pests for one
season.

Infested grain can be fumigated to destroy troublesome insect pests.
Various compounds are recommended for grain fumigation; example:
carbon tetrachloride, carbon bisulfide, ethylene dichloride. Select the
right one for your job, follow labeling directions and pay attention to
these precautions:

(1) Level the top of grain surface.

(2) Apply fumigant uniformly over the entire surface.

(3) Wear a gas mask with proper canister and filters.

(4) Apply recommended dose - do not under dose.

(5) Make bin as air tight as possible.

(6) Do not smoke near treatment area or while handling the fumigant.

(7) Do not enter bin until odor is gone (may be a week or more) .

(8) Post a DANGER sign so that no one will enter fumigated premises.

Some grain storage bins are equipment with aeration ducts making
it possible to cool the grain by forcing air through it. A fumigant
may be applied by adding it to this air system.

H . Pesticide Use in Food Plants and _F ood Handling Establishments
Introduct ion

The use of pesticides in! food handling areas and processing plants
is a sensitive subject and one of considerable confusion. The general
public shares common views toward the use of pesticides in food areas,
particularly when the use is visual or odors are detectible. The
misuse of pesticides in food processing plants and food handling areas
may result in serious pesticide contamination of food. These adulter-
ated foods can subsequently be disseminated to a large population of
of people or livestock for consumption.

17

Pest Control

Pest control in food handling areas is essential for protection of
the public's health from foods contaminated by insects and vermin.

When pesticides are used for pest control the following principles must
be adhered to:

(1) Pesticides play only a secondary role in achieving pest control
in these establishments. Pesticides are not substitutes for good
sanitation and construction.

(2) The bes£ pest control is keeping pests out of structures by
exclusion and proper building design--"pest proofing."

(3) The next best method is to remove those conditions pests require
for survival and reproduction, food, shelter, moisture or water,
and warmth. This is called environmental sanitation. If the
desirable habitat is eliminated, the pest population will decline.

(4) Pesticides should only be applied in conjunction with good
sanitation and housekeeping practices. More frequent pesticide
applications are required if environmental factors responsible
for maintenance of pest populations are not removed.

(5) Pesticide use should be minimized by encouraging routine local
sanitary inspections and by education on proper sanitation and
other non-pesticide approaches to pest control (traps, attractants,
devices) .

(6) When pesticides are used, a method of application should be chosen
which most effectively minimizesthe pest as well as prevents the
pesticide from reaching food or food contact surfaces.

(7) Selection of a pesticide should be based upon a benefit - risk
evaluation.

(8) Only pesticides which are registered for use in food establishments
can be utilized.

Methods of Insecticide Application

(1) Space treatment

This method involves the dispersal of insecticides into air
by foggers, misters, aerosol devices, and vapor dispensers.

Products and their uses currently registered by EPA and MDA for
this type of application are summarized at the end of this section.

(2) Contact (non-residual) treatment

This method includes an application of wet spray applied
to kill pests on contact. Only insecticides which do not persist
may be used. Products and their uses currently registered by

18

EPA and MDA are summarized at the end of this section.

(3) Residual treatment (liquid sprays)

Application of an insecticide leaving a deposit that kills
insects which later rest or crawl on the treated surfaces
comprises a residual treatment. Such treatments are applied to
breeding places, harborages, and areas where pests are present
or anticipated to visit. Residual insecticides are not to be
applied to food or food contact surfaces. Residual insecticides
applied indoors should be made with birushes or with sprays
operated at low pressures and in such a manner as to avoid
spattering or drifting spray mist. Residual treatments may be
of three types:

a. General Treatment - the application of pesticides over
surfaces such as walls, floors, and ceilings, or as outside
treatment to walls, eaves, lawns, and shrubs. General
treatment should be confined to outside areas and non-food
areas indoors. Under certain conditions, food storage
areas may be treated.

b. Spot Treatment - a restrictive application confined to two
square feet or less of the floor or lower wall surface.

Spot treatment applications are limited to selected surfaces,
or cracks and crevices where pests have been seen or are
suspected of visiting or occupying. Spot treatment of
residuals should be confined to outside areas, non-food
areas, and in some cases food storage areas. Spot treatment
should only be used in food processing areas in cases of
extreme infestations.

c. Crack and Crevice Treatment - the application of small
amounts of insecticides in a careful and precise manner
into cracks and crevices in which insects hide or through
which they may enter the building. Such openings commonly
occur at expansion joints, between different elements of
construction, and between equipment and floors. These
openings may lead to voids such as hollow walls, equipment
legs and bases, conduits, motor housingsoor junction switch
boxes. Treatment should be carried out to thoroughly cover
all cracks and crevices, and other concealed pest entries
and harborages, and to minimize any potential for contamin-
ation of exposed portions of floors, walls, food contact
surfaces, food, and food containers. Crack and crevice
application can be made in both the food and non-food areas
of establishments.

(4) Other Materials Used in Residual Treatments

a. Dusts - are finely divided solid particles of a toxicant,
with or without an inert carrier. Dusts are useful in
treating switch boxes and electrical motors, or to treat

19

recesses such as wall voids. Dust must not be placed
where they are likely to be transferred to food, containers,
or food contact surfaces. Dusts should be avoided where
there is wind, sweeping, foot traffic, and other activities
causing the dust to be transferred or become air-borne.

Any dust left in the open after application must be removed.
Dusts should not be used in or near processing areas.

b. Granules - are coarse particles of an inert carrier impreg-
nated or coated with a toxicant. Granules are used in
outdoor applications for insects living in or on the soil.
They should not be applied in areas where they could become
tracked indoors.

c. Baits - may be used only in confined and enclosed spaces or
at and below floor level. They should not be used in
situations where they may contact food products or containers.
They can be used outside for controlling crawling and

flying insects.

Method of Rodenticide Application

Only rodenticides of low and medium hazard classification should be
used in or around food handling and food preparation establishments.

Low hazard rodenticides include the anticoagulants, red squill and ANTU.
Medium hazard rodenticides include strychnine. Bait mixing and place-
ment should be done in areas where food is not stored, prepared or
served. Tracking powder rodenticides should not be used in food
establishments. Refer to the summary of registered products at the end
of this section.

Guidelines for Use of Pesticides in Food Handling and Food Processing
Plants. “

1. Outdoor Area Food Establishment

Pest problems usually begin outside. With proper sanitational
practices and prudent pesticide applications to outside resting,
harborage, and breeding areas, pests can be destroyed or dis-
couraged, and migration to indoor areas prevented. Special
attention should be given to washing outside and inside surfaces
of garbage cans; washing outside walls and vents; routine
removal and litter pick-up; washing down outside pavement; main-
taining healthy vegetation and lawns, and other practices which
would ultimately reduce odors and harborage sites. A good
exclusion program using such barriers as self-closing doors,
screens, air-curtains, rodent-proofing, and traps, should be
encouraged .

a. Insecticides - if required, must be applied so they neither
contact food products stored outdoors, nor enter or are
carried into the establ ishment . Special care is required
in making applications around windows, doorways, ventilators.

20

and other openings leading to the inside. Insecticides
should not be applied in or around serving windows.
Insecticides outdoors can be applied as a space treatment,
contact treatment, or residual treatment, or dusts and baits.

b. Rodenticides - may be used outside as attractive food baits
or in water solutions to intercept rodents before they gain
entry into the establishment. Such baits require adequate
bait boxes to protect animals and children and to void
contamination of food. The use of rodenticides outdoors
is considered in two categories:

(1) Public - areas not enclosed and readily accessible
to the public. Only low hazard rodenticides should
be used .

(2) Restricted - not accessible to the public. Fenced

or other barriers. Such areas include power stations
or refuse areas. Medium or low hazard rodenticides
may be used.

2. Non-Food Areas

These areas include offices, locker rooms, toilets, machine rooms,
boiler rooms, rubbish rooms, and garbage. Control efforts in these
areas are directed at pests which may wander into or breed in these
non-food areas, and subsequently migrate into food areas. Non-food
areas should be neat, free of litter and debris and well lighted.
Restrooms should be kept clean and odorless.

a. Insecticides can be applied in non-food areas as space treat-
ments, contact or residual sprays, dusts, and as baits.

However, it is imperative that prior to the selection of a
pesticide or its method of application, thoughtful considera-
tion be given to the size and layout of the establishment,
foot traffic, or any other items which (through transferral
or air currents) could contribute to product contamination.

Dusts may be used only where conditions preclude their being
tracked or carried by air currents into food areas (e.g.
switch boxes, wall voids are examples). Space treatment is
determined by the size of the establishment, construction,
ventilation, etc., which would contribute to contamination of
stored foods or food processing surfaces. Contact sprays and
residual sprays can be applied as conditions dictate. These
sprays, if properly applied, will stay where directed.

b. Rodenticides should be placed in concealed locations, in
special bait containers and bait boxes, containing a warning
statement. Use of rodenticides in these areas should be
dictated by the conditions of exposure:

(1) Public - access by the general public. Use low hazard
rodenticides .

(2) Employee only - only authorized persons allowed. Use
low hazard rodenticides.

21

(3) Restricted - physical location and construction
can be used, e. g. crawl spaces and wall voids.

Baits in public areas should be placed during off
hours only and picked up and destroyed at the
beginning of each day's operation. Dead rats and mice
should be picked up and discarded.

3. Food Storage Areas

These areas vary from shelf storage, open floor storage to
sealed tanks and are for the storage of new commodities,
intermediates, finished products as well as containers and pack-
aging materials. Food materials may be stored in bulk, bags,
cases, boxes or cans. Pest populations can be controlled with
proper environmental management of stored food areas. Bulk foods
should be stored in rodent-proof containers. Stacked foods
should be stacked in orderly rows and up off the floor to
facilitate inspection and other non-pesticidal control methods.

All spilled materials should be cleaned up and not allowed to
remain on the floor or shelves. All windows and doors should be
tight fitting and walls should be of sound construction.

Pesticides are applied in food storage areas to prevent pests from
contaminating a raw product, the finished product, or its container.
Their use helps to avoid infestations which could spread to other
processing areas.

a. Insecticides can be applied as space treatments, contact or
residual sprays, baits, and dusts. Consideration, should
first be given to the type of packaging used. All pre-
cautions must be taken to avoid treatment that would cause
food to be contaminated when it is removed from the container
and to avoid the potential for migration of the chemical
through the packaging material. Pesticide applications
should not be made where stored foods are open. Food con-
tainers such as burlap should be considered "open-food".

b. Rodenticides Use of rodenticides in food storage areas
depends upon the exposure of foods and the resulting potential
for contamination by rodenticides. Rodenticides should not

be used in storage areas where food is left uncovered, or
so packaged that it could become accidentally contaminated.
Storage areas are not considered as exposed food areas if
food is packaged in cans, jars, or other materials imper-
vious to rodenticides. Any storage facility may contain
both exposed and non-exposed foods. Rodenticides in these
areas should be placed in bait containers in labeled bait
stations. Exposed rodenticides should not be allowed to
remain out during working hours. Rodenticides should be
colored to distinguish them from other food stuffs and
placed at or below floor level to prevent contamination of
food stuffs. Only low hazard rodenticides should be used
in food storage areas.

22

4. Food Processing Areas

These areas may be completely enclosed systems of conveyance
and processing, or those in which foods are exposed for varying
periods of time. The latter are areas of a food establ ishment
requiring the greatest care to avoid exposure of food to
pesticides. Pest problems in this area can be largely eliminated
if environmental sanitation practices are exercised to reduce or
eliminate pest habitat outside, in non-food areas, in food storage
areas, and in food processing areas. Odors, food material, and
dust can be easily eliminated through regular clean-up and
washing of appliances and machines, food preparation surfaces,
waste cans, floors, walls, and windows. Surfaces which can collect
organic debris should be cleaned and kept free of cracks and joints.
Careful consideration should be given to the use of pesticides
in this area if a pest problem exists in spite of good environmental
sanitation. If the pest problem is of a minor nature, a mechan-
ical means of control should be considered.

a. Insecticides - if required, should be used with extreme
caution .

(1) Food Contact Surfaces - pesticides should not be used
on any food contact surfaces if at all possible. Under
conditions which may warrant their use, Allethrin,
Pyrethrim , and similar non-residual pesticides may be
used. The food contact surface must be cleaned after
their use.

(2) Non-food contact surfaces of equipment --Non-residual
contact insecticides may be applied in small amounts.
Care must be taken not to contaminate food contact
surfaces. Certain residual pesticides may be applied
to cracks and crevices.

(3) Floor and lower wal 1 s--Selected treatments can be
made using contact or residual insecticides applied
in cracks and crevices. Applications should be
restricted to cracks and crevices unless the infesta-
tion is unusual. Spot treatments, should be restricted
to areas below food contact surfaces such as lower
portions of walls, undersides of shelving, and the
bases of equipment. Special care should be exercised
in avoiding drift into food contact surfaces or into
food itself.

(4) Overhead areas-- Care is needed in treating upper walls
and overhead objects to prevent contamination of food
products or food contact surfaces. During any treat-
ment of overhead areas, exposed food or food contact
surfaces should be removed or covered. Residual sprays
can only be used in cracks and crevices and should be
confined to walls. Application should generally be
restricted to non-residual contact sprays.

23

(o) Space Treatment Food must be removed or covered
and all food contact surfaces covered and cleaned
after use. Space treatment application should be
made when the establishment is not in operation and
only when infestations are of an unusual and
persistant nature.

b‘ J^ent icides-- are not to be used when foods are exposed

°u workin8 hours . Bait containers and bait stations

should be restricted to the floor and picked up at the
beginning of each days work. Only rodenticides of a low
order of hazard should be used.

Pesticide Materials Registered For Use

Residual, non-residual and bait-type insecticides currently regis-

wherp r°YSe in food. Processing plants, restaurants, or other areas
where food is commercially prepared or processed are listed below
(prepared by the Criteria and Evaluation Division, EPA (Revised 2/9/73)

Group I ;

incJ^Lf °ll°"!;nL™SeCtJ^deS a^6 currentlX registered for use as residual
insect !c id es in the inedible product areas of food processing Dlants

cessedranThes°r Wh6re f°°d iS commercia]1y prepared, or’pro-

cessed. These materials must not be used in any areas where food is exposed.

Baygon

carbaryl

Chlordane

Diazinon

dicapthon

dichlorvox (DDVP)

dimethoate

Dipt er ex

Dursban

Fenthion

heptachlor

Lindane

Malathion

methoxychlor

Naled

Perthane

Ronnel

Rotenone

Strobane

toxaphene

label inpUCtMnoe8irered-f0ruthiS US® mUSt bear the fol] owing precautionary
labeling. "Do not use in the edible products area of food processing plants

res tyrants or other areas where food is commercially prepared or Jrocesed’
Do not use in serving areas while food is exposed." processed.

Group II.

spra?T^TV^FFhpnTMCideSaWhiCh ^ alS° re8istered for use as space-
-P rays 0 ly’ ln the edible product areas of food processing Dlants '

restaurants, or other areas where food is commercially prepared or 'processed :

dichlorvos (DDVP) Naled

Malathion Ronnel

methoxychlor

24

Products registered for this use must bear the following precautionary
labeling: "Food should be removed or covered during treatment. All food
processing surfaces should be covered during treatment or thoroughly cleaned
before using. When using the product in these areas, apply only when the
facility is not in operation."

If any products of this type are to be applied in such a manner as to
leave a residual deposit, they automatically fall under Group I and are
subject to that precautionary labeling.

NOTE: The Montana Department of Health and Environmental Sciences does

not approve the use of residual type space sprays in edible
product areas of establishments, unless after all environmental
sanitation efforts have been made, a severe pest infestation
persists.

Group III.

Non-residual type insecticides and synergists which are currently
registered for use as space and contact treatments in the edible products
areas of food processing plants, restaurants or other areas where food is
prepared or processed:

Allethrin Pyrethrin

d-trans allethrin Rotenone

Lethane 384 SBP-1382

MGK-264 Thanite

piperonyl butoxide Tropital

Products registered for these uses must bear the following precautionary
labeling: "Food should be removed or covered during treatment. All food

processing surfaces should be covered during treatment or thoroughly cleaned
before using. When using the product in these areas, apply only when the
facility is not in operation."

Group IV.

Non-residual type insecticides and synergists which are currently
registered for use in automatic activation devices in the edible product
areas of food processing plants, restaurant or other areas where food is
prepared or processed :

d-trans allethrin Pyrethrin

MGK-264 Stabiline

piperonyl butoxide Tropital

Products registered for this use must bear the following precautionary
labeling: "Food should be removed or covered during treatment. All food
processing surfaces should be covered during treatment or thoroughly cleaned
before using. When using the product in these areas, apply only when the
facility is not in operation."

Currently registered products of this type are awaiting a final decision
from the Environmental Protection Agency.

25

Group V:

Bait -type products prepared and applied in separate containers which
are permitted with directions for use in exposed food areas during periods
when operations are shut down and all food and food handling surfaces are
removed or well protected. Cleaning procedures are required before
operations are resumed. All bait containers should be removed and accounted
for at this time.

Baygon

Kepone

Products registered for this use must bear the following precautionary
labeling: "Use only when the facility is not in operation and food is not

exposed. Use only in bait boxes where bait in each box can be accounted
for. Remove and account for all bait prior to resuming food processing."

Group VI :

Vaporizing type insecticides which are currently registered for use in
^le 3-nedible areas of food processing plants, restaurants, or other areas
where food is prepared or processed:

Allathrin (vaporizers)

Lindane (vaporizers)

Vapona (DDVP) (strips)

Products registered for this use must bear the following precautionary
labeling: "Do not use in kitchens, restaurants or areas where food is

prepared or served," or "Do not use in the edible products areas of food
processing plants, restaurants, or other areas where food is prepared or
processed."

Group VII:

Dry, powdered type products such as silica aerosol gels, boric acid,
pyrethrum^ borax, and other powders may be used in the inedible product*
areas of food processing plants, restaurants, or other areas where food is
commercially prepared or processed.

Products registered for this use must bear the following precautionary
labeling: "Do not use in the edible product areas of food processing

plants, restaurants, or other areas where food is commercially prepared or
processed. Do not use in serving areas while food is exposed.

Group VIII:

An additional specialized usage includes concentrations of sodium
rluoride (40% or less) which are restricted to areas which are inaccessible
to children and pets. Any powder visible after application is completed
should be carefully brushed into cracks and crevices or else removed.

Products registered for this use must bear the following precautionary
labeling: "Do not use in the edible product areas of food processing plants,

26

restaurants, or other areas where food is commercially prepared or processed
Do not use in serving areas while food is exposed."

No attempt has been made to cover all powders, specific products, or
unusual formulations or mixtures of pesticides.

This information is subject to periodical revision and updating as a
result of the addition of new or cancellation of old insecticide products,
or the issuance of food additive tolerance regulations which could relax
the present precautionary statements governing the use of these materials
in food handling establishments.

Group IX:

Residual insecticides authorized by EPA for careful and precise crack
and crevices treatment in food areas (Federal Register, August 2, 1973) .

borax (finely divided powder)

boric acid (finely divided powder)

carbaryl

Ghlordane

chlorpyrifos

DDVP

Dipterex

Diazinon

Fenthion (Baytex) Entex

Baygon

Malathion

MGK-264

piperonyl butoxide

Pyrethrin

Ronnel

silica gel (finely divided
powder)

Application of these insecticides must be made after operating hours.
Food should be removed or covered during treatment. All food processing
surfaces should be covered during treatment or thoroughly cleaned before
using. These residuals can be used in "areas of receiving, serving,
boxing), preparing (cleaning, slicing, cooking, grinding), edible waste
storage and closed processing systems (mills, dairies, edible oils, syrups).'

27

I. Structural Pest Control

Introduction

Insects of various types often attack wood and other structural
materials. Agents such as lightening, wind, water, fungi, birds,
rodents, and insects may damage structural materials allowing secondary
insects and fungi to invade them causing further damage and decay.
Weakening structural supports by wood destroying insects may present
a hazard to building occupants. Some of the more common structural
pests are:

1. Termites

a. Subterranean Termites:

In Montana, one termite species, Reticulitermes
tibialis , is native. Except for a few areas in Montana,
subterranean termites are not a structural problem as they
are found in areas removed from urban centers. Subterranean
termites have been found in the Bitterroot Valley, near
Fromberg south of Billings, Billings and in Helena, and
periodically in the Sidney, Glendive and Terry areas.

Subterranean termites are social insects that live in
nests or colonies in the ground. Each colony is made up of
three forms or castes i.e. reproductives, workers, and
soldiers. Each individual of each caste passes through
three stages - egg, nymph and adult.

The principle food of termites is cellulose obtained
from wood and other plant tissue. Subterranean termites are
the most distructive species of termites in North America.
They commonly infest wood in the soil or wood that can be
reached from the soil by means of covered runways. Serious
damage results to wood buildings, fence posts, telephone
poles, paper and fiberboard.

Subterranean termites prefer moist, warm soil containing
an abundant supply of wood, roots and other wood debris.

Most termite infestations in buildings occur because wood
touches or is close to the ground. Cracks and voids in
concrete foundations make it possible for termites to reach
wooden structures that do not reach the soil. Termite
activity is prolonged or increased in northern areas when
soil around basements is heated or kept warm.

Good sanitation, design and building construction is the
best way to prevent termite infestations (e.g. removal of
wood in soil, drainage, ventilation beneath buildings,
breaking contact between soil and wood by 18 inches, and use
of treated lumber for maintenance, repair, and in new
construction) .

23

Chemical control is most effective when used in con-
junction with basic sanitation and structural control
methods. The soil most frequented by termites must be
found. An application of a chemical soil barrier can be
made as required. The soil, between the foundation and the
termite nest may be dug and treated with a residual insecti
cide. Chemicals may also be applied to the bottom of a
trench along the inside and outside of the foundation and
then filled with dirt. Mud tubes where termites go from
soil to wood should be broken.

b. Carpenter Ants

Unlike termites, carpenter ants do not feed on wood
but merely excavate wood to provide their home. Carpenter
ants forage principly for dead insects and aphid honeydew.
Carpenter ant infestations are often first recognized by
the piles of "sawdust" excavated by the ants from their
tunnels. Carpenter ant tunneling can present serious
structural damage in wooden or wooden frame buildings.
Chlordane to is an effective insecticide for controlling
carpenter ants and should be placed in or near the site of
infestation .

c . Powder post Beetles

There are three families of powder post beetles that
commonly infest wood products and structures. Beetles in
the family Lyctidae reduce wood to a fine powder, while
beetles in the family Anobiidae and Bostrichidae produce
coarse sawdust or fass. Wood infested with powder post
beetles will exhibit small circular holes 1/32 to 3/8 inch
in diameter. Because of the wide variety of materials
attacked by these beetles, chemical control often requires
special techniques. Insecticides recommended for use
against powder post beetles must be carefully selected for
each treatment area.

d . Buprestids and Cerambycids

These beetles commonly attack seasoned wood and wood
in service. Larvae of Buprestids (flat head borers) bore
into both living and dead wood forming eliptecal exit holes
These beetles may survive in cured wood for twenty years
or more. Cerambycid (round headed borers) larvae also
attack living and dead wood but their exit holes are more
round then those of Buprestids.

Control is much the same as for other wood boring
beetles. Chlordane and Lindane have been used effectively,
but selection of the proper insecticide is governed by the
treatment situation.

29

J. Animal Pests

Birds

Anyone who plans to control bird populations must be informed
as to federal and state laws, local ordinances and attitudes of local
groups. Birds which are apt to be pests are the common pigeon
(Columbia livia); the English sparrow (Passer domesticus) ;the
European starling (Sturnus vulgaris), and the barn swallow (Hirundo
erythrogaster)

1 . Common Pigeons

The common pigeon also called the rock dove, is familiar to
most persons. Their defecation on buildings and sidewalks are
problems in most cities. They nest on ledges and in open
portions of the upper levels of buildings. They can contaminate
grain if storage facilities are not properly constructed. Several
fungus diseases, including ornithosis, are transmitted by pigeons.
The potential for transmission increases as humans are exposed to
pigeon's droppings and resultant dusts.

2 . English Sparrow

Family Ploceidae

The English sparrow or house sparrow builds nests in and
around buildings and may cause such problems as plugged roof
drains and fire hazards as well as contamination of stored foods
and other stored goods.

3 . European Starling
Family Sturnidae

This bird is a greater problem in rural areas than in cities,
particularly in stock feeding locations. They may become a problem
in cities when they seek the warmth and shelter of buildings during
cold weather.

4 . Barn Swallow
Family Hirundinindae

This swallow may build nests on the sides of public buildings.
They are nuisances because of their droppings but their nests are
also of concern since they usually contain swallow bugs which are
closely related to bedbugs. These bugs live on the blood of the
swallow but when the nest is abandoned in late summer, the bugs
may move into a building and feed on humans.

5. Control of Birds

30

Pest bird control in and around buildings primarily involves
good sanitation (reduction of food sources) and construction of
structural features which discourage nesting (exclusion and bird
proofing). Repelling devices such as sound devices, bird glues or
jellies and ammonia water mists can be effective. Trapping is
effective for removing pigeon populations. Removal of nests will
discourage continued residence. Killing programs should be a last
resort, and merit considerably more information than can be provided
here. Only pesticides registered for use on specific birds are
permitted. Migratory birds are protected and killing is illegal.

The Pesticide Control Division, Department of Agriculture should be
contacted for recommendations or consultation.

Rodents

1. Bats : Order: Chiroptera

Bats in Northern states feed on large numbers of insects and
therefore are beneficial to humans and the environment. Bats
sometimes cause annoyance in homes and buildings because of offen-
sive odors or noises; fecal droppings may deface buildings and
sometimes rabies infestations cause community concern. The part
played by bats in the overall ecology of rabies is not understood.
Rabies can be transmitted to man by a bite of an infected bat or
less commonly by urine aerosol in caves. Histoplasmosis, while
rare in Montana, can be transmitted through dust of bat droppings
in caves.

Bats are occasionally a problem when they fly into open windows
at night. They are easily removed by hands protected with a leather
glove or a towel. Screens or hardware cloth keep bats out of
buildings. Openings larger than 1/4 inch should be closed. Bat-
proofing should be accomplished between November and early March
when bats have migrated out of the state or are hibernating in
caves. If a colony should establish itself in an attic or some
other part of a building, they can be driven out' by such chemicals
as naphtalene or paradichlorobenzene . Several pounds of these
chemicals may be required. They dissipate on exposure to air
allowing the bats to return in one or two weeks or the next season.
Chemicals will substitute for bat-jjroof ing . The use of repellents
or bat -proofing while flightless young are in the nest will cause
young to starve to death, decompose and produce offensive odors.

2. Domestic Rodents: Order: Rodentia Family: Muridae

The term "domestic rodents" refer to three rodents introduced
into North America from Europe. These rodents are the Norway rat
(Rattus norwegicus) , the roof rat (Rattus rattus) , (not present
in the state), and the house mouse (Mus musculus) These rodents
can cause a great amount of destruction of food and property. They
can also be a source of such human diseases as plague, murine typhus,
leptospirosis, rat bite fever and trichinosis. Mice are known to
transmit rickettsialpox. Rats in slum areas are known to kill or
maim babies in their beds.

31

Successful control of domestic rodents is only achieved by
preventing their access to food and harborage. This is accomp-
lished primarily through good premise sanitation and building
construction, as well as through good community sanitation.

Rodent populations are suppressed with trapping, fumigation
poison baits, tracking dusts and glue boards. Rodenticides are
supplemental to and not a substitute for good management. Poisons
used for rodents are two types: multiple dose (the anticoagulants)
and the single dose (such as strychnine) .

a . Norway Rats

A number of baits are used for Norway rats: grain, seeds,
legumes, bacon, fish, sugar, corn, fruits, (e.g. apples and
tomatoes), vegetables, mineral, peanut and salad oils are
frequently used. Wheat, corn, oats, and barley are most
commonly used in poison baits. Baiting problems may be
related to food availability rather than the rodenticide
employed. Improper placement and distribution may be
responsible for control failure. In food warehouses cereal
baits may not be accepted and liquid baits may be desirable.

In extremely moist areas (indoors or outdoors) paraffin
treated baits may retard the deteriation of the baits, pro-
longing its acceptability.

b. House Mice:

Mice do not forage widely, therefore, the use of many well
distributed small anticoagulant baits is preferable. Because
mice nibble when feeding, a high concentration of anticoagu-
lant is required to reduce control failures. Frequent
renewal of baits is a must since mice reject old baits. Liquid
baits are usually not desirable because mice have low water
requirements. Rodent ectoparasites can be controlled at the
same time as rodents. Spreading insecticide dust in runways
or in burrows is the recommended procedure.

c . Skunks :

Skunks usually live in underground burrows, rock piles or
hollow logs, and may be found under buildings if construction
permits entry. Besides the odor associated with skunks they
aie also carriers of rabies. Rabid skunks can become very
aggressive and easily transmit rabies to domestic animals or
humans. Large skunk populations may be a potential threat
to domestic animals and to humans.

Control of skunks includes preventing entrance to buildings,
trapping, shooting and denning. Trapping, while fairly non-
specific can be effective but includes the potential of scent
release. Quick acting poisons such as strychnine treated
®ggs are very effective but can only be used by certain gov-
ernment agencies.

32

d. Trapping ;

Traps are a preferred method of control where rodenticide
use should be avoided, when dead animals may die in an
inaccessible area and cause annoying odors, or where a few
surviving rodents become poison bait shy. Both wood base
and steel traps are effective; mice are more easily trapped
with snap traps and rats tend to be more wary of traps.

Mouse traps must be set close together (3-4 foot intervals)
against baseboards, boxes and platforms. Baits for house
mice include rolled oats, peanut butter, gum drops, raisin
bread, bacon and nut meats. Traps for rat control should
be placed in rat runs. Baits for rats include bacon, fish,
ground meat, raisin bread, nut meats, prunes and apples.

e. Fumigating :

Fumigation provides a quick kill. However, rodents will
die in inaccessible areas and decompose and produce odors.

For these reasons it is not recommended for general rodent
control. Unless a situation absolutely warrants their use
fumigants should not be considered. Fumigants should be
applied only by trained personnel.

f. Poisons

(1) Multiple-Dose (anticoagulant) Rodenticides

Anticoagulant poisons include pivalyn, warfarin.
diphacinone, Fumarin,and chlorophacinone . Anti-
coagulants are the safest of the rodent poisons.

They must be eaten by rodents over a period of
several days and should be made available for a
period of 10-20 days. Establishment of permanent
bait stations in places subject to continued
reinfestation gives good control, provided old baits
are periodically replaced by fresh ones. Liquid
baits work best where the rodent's water supply
can be controlled. Anticoagulants work best for
Norway rats, less so with roof rats and house mice.
For house mice, fresh bait should be made available
for a minimum of 14 days.

(2) Single-Dose (acute poisons) Rodenticides

Single dose rodenticides including sodium fluroa-
cetate (1080), fluroacetamide, (1081), norbormide,
red squill , ANTU and zinc phosphide. Pre-baiting
(offering plain bait for several nights prior to
adding poison) will greatly increase the effect-
iveness of acute poisons.

a. Norbormide is a specific poison used to kill
Norway rats. It is very erratic with roof rats

33

and has no effect on house mice. Norbormide
kills Norway rats in 15 minutes to one hour.

b. ANTU is very effective against Norway rats but
has little effect on roof rats or house mice.

It may be mixed with regular food baits or used
as a tracking powder.

c- Red Squill is a red powder, effective in baits
against Norway rats and as a tracking powder
against house mice.

d. Strychnine is effective only against house mice;
rats quickly detect its presence because of its
bitter tastes. Strychnine baits (0.3-0. 5%
strychnine) are sometimes used against mice,
baits should be handled with care.

e* Zinc Phosphide is effective against all three
domestic rodents. Zinc phosphide is moderately
fast acting. The powder releases phorphine
gases when it contacts stomach acids. Both the
powder and gas are extremely toxic.

f- Fluoroacet amide (1081) and sodium fluoracetate
(1080) Both 1081 and 1080 are so highly toxic
and hazardous that their use is restricted to
special situations, and to professionally
trained personnel . There are no known antidotes
for either of these poisons. Both 1080 and
1081 are effective against Norway rats, roof
rats and house mice.

1080 and 1081 should be placed in locked bait
boxes and all precautions taken to protect the
skin from contact with the chemicals.

8- Tracking Powder Non-Toxic tracking dusts (flour
or talc) should only be used to check rodent
activity in food areas and areas where pets or
children may be exposed.

Tracking dusts may also be used to get a rodent
to ingest materials they would normally not eat
in a food bait (e.g. reg squill).

h. Baits The acceptability of a bait is a critical
factor in controlling rodent populations. Often
a "trial and error" approach in finding a bait
acceptable to specific rodent populations is
necessary .

34

References

1 . Guidelines to the use of Pesticides in Food Plants and Other
Commercial Food Handling Establishments . National Pest Control
Association, The Buettner Building, 250 West Jersey Street,
Elizabeth, N.J. 07207.

2. Pest Control in Food Processing Plants and Other Food Handling Areas
Hazardous Materials Advisory Committee, EPA, February 1972

3. Residual , Non-Residual and Bait Type Insecticides Currently

Registered for Use In Food Processing Plants, Restaurants, or Other
Areas Where Food is Commercially Prepared or Processed. Criteria
and Evaluation Division, EPA, Pesticide Office, Washington, D.C.
20250. 2/9/73

4. Insecticides in Food Handling Establishments. Federal Register,

Vol . 38, No. 154, August 10, 1973.

35

CHAPTER II

MOSQUITOES AND THEIR CONTROL

A. Philosophy

It is necessary to understand the life cycle and habits of
mosquito species in order to effectively and efficiently control
mosquito populations. Detailed surveys are essential for the planning,
operation and evaluation of control programs. Survey and evaluation
are continuing processes that must accompany control. A basic tenet
for mosquito control is that only by treatment of cause (larval
mosquito habitat) rather than effect (mosquito populations) can a
problem become less severe. For this reason and since mosquitoes
require shallow standing water for development, good water management
practices/ source reduction methods are the preferred approaches in
mosquito control. As a practical matter, the use of chemicals will
be required for the temporary suppression of mosquito populations.
Chemical control should assume less importance as source reduction
programs develop. In all cases, the least environmentally disrupting
approach to mosquito control should be used.

Control programs conducted by mosquito control districts organized
under state enabling legislation (R.C.M. 1947, 16-4201 through 16-4214)
have been the most effective. Districts thus organized have more
program continuity, higher levels of financing and a more reliable
source of financial support. These advantages make environmentally
sound source reduction and larviciding programs easier to attain.

The vector control specialist of the Environmental Services
Bureau may be contacted for technical advice, information or assistance
in forming mosquito control. 'districts or for reviewing and consultation
upon mosquito control programs and problems.

B. Mosquito Biology

There are 43 species of mosquitoes in Montana distributed among
six genera (Aedes , Anopholes , Culex , Guliseta , Coquilletidia and
Psorophora ) . Vector Control Bulletin #1, Montana Mosquitoes, Part I,
Identification and Biology (obtainable from the Department of Health)
may be consulted for detailed information. The most common mosquitoes
are Aedes species. Most control efforts are directed at this group.

The other common genera are Culex and Culiseta . The mosquito species
Culex tar sal is is of public health importance in Montana because it is
the principle vector of human and equine encephalitis. Other species
have also been found to be naturally infected with the virus causing
this disease.

All mosquito species have four distinct stages in their life
cycle: (complete metamarphosis ) the egg, the larva (wiggler), the pupa
(tumbler) and the adult. The first three stages require water for
development. Eggs of all species (except Aedes and Psoro.phOra) and
all larvae and pupae will die out of water. (Pupae can survive for

36

short periods in moist environments).

Aedes and Isorophora ~ species normally lay their eggs in the
mud along receding waters. (One rare Aedes species lay its eggs
above the water line in tree holes or containers). Eggs of some
Aedes species will hatch If the site is flooded again that season.

Others must be subjected to cold before hatching. Hence, some species
have only one generation each year; others may have several generations.
Aedes are a temporary water mosquito, implying that they are produced
in water which is retained on the surface for a minimum of about 7
days but which normally disappears during the course of the season.

They may also be found in permanent or semi-permanent bodies of water
which have periodic fluctuations in water levels. Eggs of some Aedes
species retain the ability to hatch if flooded even after a peroid
of 5 years on dry land. Aedes overwinter in the stage.

Eggs of the Culex and Culiseta species are laid in rafts on the
surface of permanent or semi-permanent bodies of water. Eggs of
Anopholes (which are not too common) species are laid singly on the
water surface, Eggs of these permanent water mosquitoes must have
water continuously to remain viable. While Coquilletidia overwinter
in the larval stage, the Culex, Culiseta, and Anopholes species
overwinter in the adult stage in sheltered sites. Since there is
a high mortality of adults of these species during the winter, their
populations do not usually build up until later in the season. The
permanent water mosquitoes typically have several generations each
year.

Water temperature is the most critical factor in the hatching
of eggs and in the time required for development. Eggs of the
predominant Aedes species may hatch when the daily average water
temperature reaches about 50°F. but they do not hatch in large numbers
until the daily average water temperature approaches 70°F. Besides
water temperature, the rate of larval development depends on the
species and amount of nutrients available. Larval and pupal development
may be completed in as little as 5 days (more likely 7 to 8 days)
in hot weather or development may take 3 weeks when the water
temperature is cooler. All larvae (except Coquilletidia , which is
fairly rare) must come to the surface to breathe; hence the effectiveness
of oils which foul the breathing apparatus and cut off the air supply.

The adult mosquitoes feed mainly at night, being most active at
dawn and at dusk. A few Aedes species will attack during broad
daylight (especially if distrubed) but most prefer shaded situations
if they bite at all during daylight hours. Different mosquito species
show different host preferences. Culex tarsalis, the common encephalitis
mosquito, readily bites man but prefers to feed on birds. Culex
territans feed exclusively on reptiles and amphibians.

The normal flight range of most Anopholes, Culex and Culiseta
species is usually considered to be one mile or less. However, studies
have shown that Culex tarsalis commonly fly from 3 to 10 miles, especially
when seeking shelter in the fall. Most Aedes species are strong

37

c.

fliers and range several miles from their "breeding places.

Individuals have been recaptured over 20 miles from their release
site but most range three miles or less. Mosquitoes will normally
fly no further from their breeding sites than is necessary to feed.

Classification of Mosquito Breeding Places

Mosquito breeding places may be classed as temporary, permanent
or semi -permanent. Temporary breeding pools remain for a limited
period of time following each flooding. Permanent water remains
throughout the year. Semi-permanent water areas remain throughout
most or all of a mosquito season following an initial flooding.

Mosquito breeding places may also be classified as to their
location. They may be classified as on field (including surface

"°fS^lgati°n laterals and ^ains) or off field (including road
side ditches, or borrow pits, waste land areas, abandoned canals

“ ^at!raiS’. drainaSe Pitches, natural waterways, oxbows, sloughs
and distribution systems). Over 95 percent of the total breeding
area was associated with "on field" mosquito breeding places in
one irrigated area studied in Montana. These accounted for over
T percent of all mosquito production during the entire season.

us in most areas suffering from severe mosquito infestations,
m°*? ?an 9° percent of a11 mosquito production may be associated
with the use of water for irrigation. In non-irrigated areas,

spring run-off and a rising water table account for higher percentage£
of mosquitoes produced. &

E>. Mosquito Surveys

Two types of survey are widely used:
and the operational survey

Original Basic Survey

The original basic survey

The original basic survey determines the species of mosquitoes,
their source, location and seasonal density. Mosquito control maps
are used for orientation and locating larval breeding places and ?
adult sampling stations. When making the original basic survey

nl^n^ V* reC°rd thG type °f breedinS P^ce and if known, the
fSd i e—txons of mosquitoes (e.g. temporary, on-

fieid (alfalfa), 3 generations). This information is of value for

to seasonal breeding acreage that would have

OQrib ^eated each year (as opposed to the amount of acreage that
Produce mosquitoes) and for estimating the types of control

eauinmen+tha^ ^ ^ USed* the °f P—nn2 needed!^ of

equipment and amount and type of insecticide required.

Operational Surveys

The operational survey is a continuing evaluation of the
mosquito control program and is extremely valuable in daily operations
Through operational surveys, one refines information on control
e lciency , the times that larvae appear in each source, and the

38

significance of each larval source according to the production indexes.
Such surveys determine the population index Cshowing general
fluctuations rather than determining the actual numbers of mosquitoes
present). Operational surveys may be larval or adult iflosquito surveys.

1. Larval Surveys

In conducting larval surveys, a dipper approximately
1+ infches in diameter is scooped fairly rapidly through the
water surface near emergent vegetation. Aedes larvae are
collected by a rapid skimming movement of the dipper with
one side depressed below the water surface, ending the stroke
just as the dipper is filled. Where clumps of emergent vegetation
are present, it is easiest to collect Anopholes larvae by
pressing the dipper into such clumps with one edge depressed
so that the water flows from the vegetation into the dipper.

A quicker motion is required for collection of Culicine larvae
(Aedes , Culex , Culiseta and Fsorophora) than for the collection
of Anopholes larvae since they are more likely to dive below
the surface when disturbed by shadows or movement. The number
of dips made and the number of larvae found are recorded in
order to calculate a breeding index. The breeding index may
be defined as the number of larvae per square foot of water
surface. Therefore, the number of larvae collected divided
by the number of times that 4 dips are taken equals the breeding
index (BI = ft larvae ). Unless the mosquito production
it dips (1/4)

source is very large, a mosquito breeding index of less than 1
is not normally controlled. One can determine the relative
importance of each breeding site or station by calculating
the production index (Breeding Index X the Area = Production
Index of the site or station). Both pre-treatment and post
treatment larval counts should be made when possible in order
to determine^ control efficiency.

2. Adult Surveys

Adult surveys may include biting collections, resting
collections, light trap carbon dioxide or baited collections.

Adult mosquito surveys provide information on :

(1)

the species present.

(2)

the mosquito population density,

(3)

the effectiveness of the control efforts
the season and

throughout

(4)

a means of evaluating the effectiveness
treatments .

of specific

Adult light trap collections depend upon a phototropic response.
Mosquito species differ in their response to light; some being
attracted readily, others poorly. After being attracted to the

39

light, fan is usually employed to blow the mosquitoes into
a bag or killing jar. Biting collections are carried out by
capturing the adult female mosquito with an aspirator as she
attempts to obtain a blood meal from a host. When making
population estimates with the bite count method, a predetermined
time period is established. The count per given time period
that will be tolerated by residents in an area varies from
region to region and must be determined for each area. Biting
and light trap collections are the most common forms of adult
surveys. Resting station collections are made by aspirating
the adult which remains inactive during the day, resting in
cool, humid places. Resting stations may be in such sites
as stables, chicken houses, culverts, and so forth. Egg samples
or egg-sod surveys are not typically made in Montana but
have been employed in large districts as a part of pre-
larviciding operations.

E. Methods of Control

All methods of mosquito control require surveys to insure
success. A number of general methods are employed. In order of
preference, they are good water management, source reduction,
biological control, pre-larviciding, larviciding, and adulticiding.

The one instance in which adulticiding pre-empts other control methods
is in the event of an outbreak of mosquito-borne diseases, such
as St. Louis encephalitis or Western equine encephalitis.

Source Reduction. Source reduction is accomplished by the
removal of free, shallow, standing water contributing to
mosquito production or by the elimination of harborage
present within the water. Source reduction or permanent
control may involve diking, ditching, draining, dredging,
deepening, filling or water level management.

(S) Biological Control.- Most forms of biological control remain
in the experimental stage. The use of the mosquitofish
Gambusia affinis has been effective in Montana on a limited
basis. Other experimental efforts to use fish for mosquito
control should be attempted whenever possible. The Fish
and Game Department should be notified prior to such attempts.
Algae, protozoa (particularly microsporidia ) , nematodes, fungi
(e,S- Coeleomomyces ) , irridescent viruses and the crystaloid
toxicant produced by the bacteria Bacillus thuringiensis
are examples of experimental control efforts not yet reaching
field use.

(3) pre-larviciding. Prelarviciding consists of applying

approved insecticides to areas known to produce mosquitoes
but which contain no larvae at the time of application.

Granules of either the coated or clay type and containing
1 to 2 percent concentrate (e.g. Abate, Chlorpyrifos or
Fenthion ) may be applied to the ice of snow melt pools or
to low spots that collect the annual run-off and which are
known to produce an early hatch of mosquiotes. Precisely

40

outlining this area depends upon experience, accurate surveys
and records. Areas to be treated by pre-larviciding should
be carefully selected to insure that the insecticide will
not be flushed from the area and contaminate potable water
supplies or water containing valuable resources.

(M Larviciding. It is at the larval stage of development that
mosquitoes are most effectively controlled. More mosquitoes
are killed per given quantity of insecticide by larviciding
than adulticiding because mosquito larvae are concentrated
in a restricted location and less toxicant is needed to affect
control. Since insecticide is applied over given areas at
approximately the same dosage whether adulticiding or larviciding,
more insecticide is required after adults 'disperse. Larviciding
should not be conducted without surveying a site and establishing
that mosquito larvae are present in sufficient numbers to
merit control. Larviciding is conducted by the application
of fuel oil, fuel oil plus spreader, highly refined oils,
insecticide granules, emulsifiable concentrates or solutions
to a body of water. The choice of approach and chemical depends
upon the registration of the chemical, its directions for
use and the environmental conditions present.

Besides being of value in pre-larviciding, granules
are an excellent means for applying insecticide through heavy
foilage. They will tumble through the vegetation to the
water surface rather than being deposited upon the surface
of vegetation as liquid formulations are: (The use of liquid
formulations in heavy cover may result in ineffective control
from the application of less than toxic amounts of insecticide
to both the water and the foliage ) .

The use of fuel oil should be restricted to waste land
areas not possessing valuable vegetation. Fuel oil applied
at the rate of 15 to 20 gallons per acre may burn vegetation
and leave an unsightly appearance. Fuel oil with a spreading
agent applied at 2 to 3 gallons per acre is slightly less
objectionable. The more highly refined mosquito control oils
have not been reported to have this toxic effect.

When applying an insecticide for mosquito control, the
applicator must insure that the insecticide is also registered
for application to crops in that area. For example, a
flooded alfalfa field containing mosquito larvae should be
treated with a chemical registered for both mosquito control
and for use on alfalfa pests.

(5) Adulticiding. Adulticiding is conducted through the use of
thermal fogging, misting or ULV equipment. Adulticiding is
the most difficult form of mosquito control to practice
in terms of applying the correct dosage and obtaining tbe
proper coverage that is necessary for efficient control.
Disadvantages are that there is less control of exposure
to non-target organisms, more insecticide is used £er

mosquito killed, the effect is more temporary than it is
with, other forms of mosquito control and a repellent effect
may occur. Routine adulticiding or adulticiding only on
the basis of telephone complaints can be a useless and ex-
pensive procedure. None-the-less , adulticiding can be a
valuable supplement to other forms of mosquito control. It
is widely used to combat outbreaks of mosquito-borne disease.

Mists, fogs, and ULV applications depend upon direct
contact of the insecticide with the adult mosquito. For
this reason, they are most effective while the mosquito is
on the wing in the early morning or early evening hours.

Under ideal conditions the wind should not exceed five miles
per hour, temperature should be between 65 and 75°p ana the
relative humidity should be 60 to 80 percent. ULV application
of Malathion should not be made if the temperature exceeds
82°F. Space spraying is conducted as near as possible at
right angles to the wind. Low wind currents are depended
upon to disperse the insecticide over 300 to 400 foot
recommended swath width.

The movement of the extremely small thermal fog particles
is very unpredictable. These particles are more subject to
climatic conditions than are the larger ULV or mist particles.

ULV adulticiding (the application of 1/2 gal. or less
of undiluted concentrate per acre) results in the distribution
of more uniform particle sizes which are of a aiie sufficient to
kill the adult mosquito. It is the cheapest form of adult
mosquito control (about 1/4 that of thermal fogging) and
results in less environmental contamination. The use of diesel
fuel is eliminated and it is only necessary to apply
approximately 1/2 to 2/3 the dosage needed for thermal fogging.
However, since pure or concentrated insecticide is dispensed,
chemical and equipment use directions must be followed
rigorously and the per formance of the machine must be continually
assessed to assure that accidents do not occur. The hazard
of spotting of automobile paint increases with droplet size.

Misting machines disseminate a wide array of different
size particles. This may result in wastage of some chemical
but enables applicators to use the machine during daylight
hours and under more adverse wind and temperature conditions.
Misters can be used for short term residual mosquito control
in parks and in bushes and trees in rural or urban residential
areas. Under these conditions the mist is directed at a lower
angle than the customary 45° above the horizontal that is
used when space spraying. If vegetation is tall, the mist
should be directed at the upper part. The vehicle speed should
be 5 mph or less when treating low sparse vegetation and 3
mph or less when vegetation is dense. In the latter case
or under hot, dry conditions, the effective swath width may
not exceed 100 feet. Under more ideal conditions, it may
be 200 feet. Although one can larvicide with misters, it

42

is usually best to larvicide with equipment designed for that
purpose rather than attempt to employ adulticiding equipment
in this fashion. If equipped with a granule hopper, however,
mist blowers can be used to effectively larvicide with granules.

F. Chemicals for Mosquito Control

A variety of insecticides are registered for mosquito control.
Since registrations are periodically reviewed and certain restrictions
may be imposed, applicators should consult with the State Department
of Agriculture and State Department of Health and Environmental
Sciences prior to using them. Label directions should be followed.
Table 19 indicates pesticides currently used in mosquito control.

43

TABLE 1

PESTICIDES CURRENTLY EMPLOYED IN MOSQUITO CONTROL3-

■>

.(N

Type

Application

Toxicant13

Dosage

Residual

Spray

malathion

100 — 200 mg
per square ft.

Continuous

Vapor

Treatment

dichlorvos

1 dispenser per
1,000 cu. ft.

Outdoor ,
Ground
Applied ,

chlorpyrifose

(Dursban)

lb/ acre
0.0125

Space

Spray

fenthion0

(Baytex)

0.001-0.1

malathion

0.075-0.2

naled

0.02-0.1

pyrethrins
( synergized )

0.002-010025

Larvicide

abate

0.05-0.1

chlorpyrifosc • e

0.0125-0.05

fenthion0 • e.f

0.05-0.1

malathion

0.2-0. 5

pyrethrin tossits

1/100 sp.ft.

Remarks

For use as an interior house treatment .
Effective for 3—5 months on wood surfaces.

In resin; dispeners hung from ceilings. Gives
1/2—3 1/2 months control. Do not use where
infants, ill or aged are confined or in food
preparation or serving areas.

Dosage based on estimated 300 foot swath width.
Mists and fogs are applied from dusk to dawn.
Mists are uaually dispersed at 7 to 25 gal/mi.
and at a speed of 5 mph. Fogs are applied at
a rate of 1+0 gal/hr § 5 mpli (occasionally at
higher rates and greater speeds). Finsihed
sprays have 0.5-8 oz/gal actual insecticide
m oil or (with non— thermal foggers) water.

In Ulv ground applications^ technical grade
malathion is used at 1-1. 5 fi. oz/min. at
5 mph or 2-3 fl. oz/min § 10 mph; some ULV
pyrethrins at 2-2.25 fl. oz/min @ 5 mph or
^-4.5 fl. oz/min § 10 mph; chlorpyrifos
fog concentrate at 2/3 - 1 1/3 fl. oz/min §

10 mph.

Apply by ground or air at up to 10 quarts
finished spray/acre depending on concentration
used. Use oil or water emulsion formulations
in areas with minimum vegetation cover; granu-
lar formulations where vegetative cover is
heavy. Fenthion provides longer residual in
contaminated water at 5 times the dosage listed.
Chlorpyrifos has long residual toxicity in water
with a high organic content (e.g. 12 weeks

con-fr'a

fuel oil

Flit MLO

2 to 20 gal/A
1 to 5 gal/A

in septic tanks) while abate is fairly labile
in polluted water. Apply fuel oil at 15-20
gal/A in open water courses or with 0.5%
spreading agent (e.g. T-Det-MC, Dal-Com W)_
apply at 2-3 gal/A.

a Modified from "Public Health Pesticides" Technical Development Laboratories, Center for Disease
Control, U.S. Department Health, Education and Welfares (1973)

b Other compounds such as Lethane 384 and ronnel may have uses in some categories. If so follow
label directions.

c For use by trained mosquito control personnel only,
d Adhere STRICTLY to all label specifications and directions,
e Do not apply to waters with valuable fish.

Label requires 3 week interval between applications except for adulticiding .

■c-

Ui

f

*

*