Using Insecticides
For good insect control you must learn how to use
insecticides (chemicals) effectively. Most are available
in several formulations, each with its own use for
control in and around houses.
Those discussed here are the more common
formulations. The formulation is the way in which an
insecticide is packaged by the manufacturer for sale and
subsequent use by the consumer. This information is not
meant to replace detailed information given on
insecticide containers; always read the label for
specific use instructions.
Emulsifiable Concentrates (EC)
Emulsifiable concentrates are liquids. They must be
mixed with water, turning it milky (the emulsion). Apply
them outdoors both to plants and around foundations. Be
careful when applying to young, tender flowers and
shrubs, for they may injure these plants. In concentrated
form, emulsifiable concentrates are dangerous if spilled
on clothing and skin. Change clothing and use masks and
protective clothing while spraying, especially if
applying dangerous materials over a long period of time.
Launder contaminated clothing separately, then thoroughly
rinse out the washing machine.
Solutions (S)
Solutions are also liquids. They differ from
emulsions in that they are ready to use and ARE NOT MIXED
WITH WATER. They are made with refined (deodorized)
kerosene or similar materials, plus an insecticide. Use
them indoors to control household insects. Do not apply
to plants, for they cause severe injury. Solutions are
dangerous if spilled on clothing and skin. Immediately
wash off with soap and water and change clothing. Launder
contaminated clothing separately, then thoroughly rinse
out washing machine. For other instructions, see
emulsifiable concentrates above. Deodorized kerosene is
difficult to obtain in small quantities today, so most
liquid insecticides must be used a emulsifiable
concentrates.
Wettable Powders (WP)
These are similar to dusts (see below), but they
contain a higher percentage of chemical and are mixed
with water and applied as sprays. The spray is seldom
used indoors, but is useful when applied outdoors. Avoid
breathing or getting powder (or spray) on the skin. Use
masks and protective clothing, especially if applying
dangerous materials over a long period of time.
Dusts (D)
Dusts are dry powders which normally contain a lower
percentage of insecticide than wettable powders. They are
used as bought and ARE NOT MIXED WITH WATER. Use them
both indoors and outdoors as previously specified. They
are especially suited to treatment of cracks and
crevices, wall voids and other seldom disturbed areas.
They loose much of there effectiveness when exposed to
moisture because of their tendency to form lumps.
Aerosols and Foggers
Aerosols and foggers are liquids held under pressure
in a container. When released, usually by pressing a
button, some form a gas, others a spray. "Gas-producing"
(space spray) types are used for control of flying
insects (such as flies). As either a total-release "bug
bombs" (foggers) or trigger controlled spray can, they
are designed to clear rooms or large number of exposed
flying insects. They have no residual action and,
therefore, will not kill insects which emerge from
protected crevices or other rooms after the treatment.
The liquid types (contact residuals) are designed for
insects that crawl or run on floors (such as ants and
roaches). These materials deposit a toxic residue on
surfaces where insects rest and travel and kill pests
over an extended period of time. Choose the right one to
fit your needs.
Baits and Bait Traps
These are mixtures of a food bait and a poison. The
bait and poison mixture may be placed in a special bait
trap, or it may be a liquid designed to be spread on
small pieces of cardboard. In either case, place all
baits in areas where they are not readily accessible by
children and pets.
Fumigants and Repellents
These are insecticides that readily vaporize into the
atmosphere and give off gases which kill or repel
insects. Fumigants may be sold as solids, liquids or in
liquid-impregnated resin strips.
Special Formulations
Some insecticides come in special formulations such
as insecticide impregnated tape or insecticidal paints.
These are designed to expose insect pests to toxic
surfaces, thereby killing them.
Application Equipment
The compressed air sprayer, the quart-sized sprayer,
the aerosol can, the paint brush and the bulb duster are
probably the best kinds of equipment for the home owner
to use for applying household insecticides. Each type of
equipment has both good features and disadvantages.
Careful study of your insect control jobs will help you
buy and use the best type effectively.
Compressed Air Sprayer
The water capacity of a compressed air sprayer is
usually one to four gallons. Air is pumped into the tank,
forcing the spray out when the nozzle is opened. It is
ideal for outdoor application of wettable powders and
emulsions. Its use indoors is limited if a lot of water
is applied with the insecticide. Shake the sprayer
frequently when using a wettable powder.
Quart-sized Sprayer
The quart-sized sprayer is also a compressed air
type, but air must be pumped into it continuously while
in use. It can be used satisfactorily with emulsions and
solutions, but not wettable powders. Use it both indoors
and outdoors for treating small areas. Note: where high
pressure is needed for good application, these have
limited use.
Paintbrush
Use an inexpensive paintbrush to apply insecticide
solutions to baseboards, screens, and similar areas
inside buildings. A light film is usually sufficient.
Bulb Duster
This apparatus is used for applying dusts to cracks,
crevices and other voids. The dust is placed into the
bulb or bellows; squeezing the device forces the dust out
the nozzle and into the void to be treated. A little bit
of practice (with plaster or Paris of flour) will help
you perfect your dusting technique. Best results are
achieved when dusts are applied in a thin, even layer. If
you can easily see the dust on a surface you have used
too much!
WARNINGS
1. Inside buildings, apply registered residual contact
to small areas only (such as baseboards, corners, cracks
and crevices, etc.). Do not apply to entire rooms or
buildings. Some insecticide formulations also have a
strong odor.
2. Avoid using any insecticide around food or where
children or pets can get into it. Do not allow children
on insecticide-treated grass until 3 days after
application.
3. Avoid breathing sprays or dusts. A handkerchief fitted
to the face will help prevent excessive inhalation of
these materials. If there is a chance of breathing
highly poisonous materials, use a mask. While some
insecticides such as pyrethrum or rotenone may be harmful
to persons with asthma, the chemicals are generally quite
safe otherwise.
4. If emulsifiable concentrates or concentrated
wettable powders are spilled on the skin, wash
immediately with soap and water. Remove contaminated
clothing immediately and launder separately. Thoroughly
rinse the washing machine after use.
5. Do not use insecticides in oil (kerosene) around open
flames (pilot lights), electrical wiring, or an asphalt
floor covering. Both oil-based and water-based
insecticides which may stain or spot fabrics and other
porous surfaces.
6. Outdoors, avoid heavy applications to tender flowers
and shrubs, especially emulsions. Read labels to avoid
using any material specified as damaging to certain
plants.
7. Never puncture an aerosol can. This can cause injury.
8. Read the label for each insecticide used. Then,
follow directions.
SPECIAL WARNING
Indoors, apply only those insecticides manufactured
especially for this purpose. Formulations suitable for
treating livestock and plants of all kinds outdoors ARE
NOT GENERALLY the best types for use in buildings
(homes). For example: formulations for indoor application
should contain only the purified grade of the chemical,
not the commercial agricultural product. There is less
objectionable odor to purified grades than to the
agricultural grade. In addition to the kind of
insecticide used in household preparations, the carrier
(often an oil) should be specifically processed (refined)
to reduce or eliminate objectionable odors.
Another point to consider: When a household
pesticide is applied behind quarter-round or any other
like situation, or where there may be excessive heat,
odor from the chemicals may be more noticeable and
consequently more objectionable than the pest itself.
For a complete listing of suggested control options
for all home, yard and garden insect pests contact your
local Extension Service, found under local government in
the phone book.