Selection and Use of Household Insecticides,If Needed
Control of household insect pests is dependent upon
two factors; a knowledge of the pest and its habits AND
the selection of the proper management strategy, an
insecticide is not your only choice. If you choose to use
an insecticide it is important that you thoroughly
understand their different uses, methods of application,
limitations, and hazards. It is therefore important to
know about the selection and safe use of household
insecticides.
I. Insecticide Formulations
Formulation - the way in which an insecticide is
packaged by the manufacturer for sale and subsequent use
by the consumer.
1. FOGGERS - these are total-release aerosol cans ("bug
bombs") that generate a mist to saturate large, enclosed
spaces. They are best used to clear rooms of large
numbers of exposed insect pests. Use of these foggers
requires preparation (remove plants, pets and food; cover
furniture) and time (for fogging and ventilation after
use). The insecticides used in foggers have no residual
action, and therefore will not kill those insect pests
that emerge from protected crevices and other rooms after
the treatment. Materials used: pyrethrins plus
synergists.
2. AEROSOLS - these are similar to foggers, except the
cans are provided with a trigger which allows them to be
used in short blasts as needed. There are two different
types of aerosols:
a) Aerosol mists - these aerosols contain contact space
spray insecticides designed to knockdown and kill flying
insects. Materials commonly used: pyrethrin, d-trans-
Allethrin or resmethrin plus synergists.
b) Aerosol sprays - these aerosols contain contact
residual insecticides designed for the control of
crawling insects. These materials deposit a toxic residue
to surfaces where insects rest and travel, and will kill
pests over an extended period of time. Materials commonly
used: propoxur, chlorpyrifos, silica gel, resmethrin, or
pyrethrins plus synergists.
3. LIQUIDS - these are contact residual insecticides sold
in a concentrated form, and are mixed with water and
applied with a hand pressurized sprayer or pump bottle.
some products may come ready to use (TRU) in special
squirt bottles and these are especially useful for
applying the insecticide into cracks and crevices where
insects hide. Materials commonly used: propoxur,
chlorpyrifos, malathion, diazinon or pyrethrins plus
synergists.
4. DUSTS - or powders, are used in the dry form. they are
not mixed with water. These materials are easily
introduced into cracks and crevices where insects hide.
They lose some of their effectiveness in moist situations
because of their tendency to form lumps. Materials
commonly used: boric acid or propoxur.
5. BAITS and BAIT TRAPS - these are mixtures of food bait
and poison. The bait and poison mixture is generally
sealed in a metal can with small entrance holes for the
insects to enter. In some cases the insects may take the
poisoned bait back to the colony. Materials commonly
used: proposur, boric acid or arsenicals.
6. TAPE - these are strips of paper coated with poison on
one side and adhesive on the other. The tape is placed in
areas where the insects will walk over them and come in
contact with the insecticide. Materials commonly used:
propoxur.
7. FUMIGANTS - these are insecticides that readily
volatilize into the atmosphere and give off gases which
repel or kill insect pests. Materials commonly used:
paradichlorobenzene (PDB) or napthalene.
8. REPELLENTS - these are chemicals which are used to
repel biting insects of man and livestock. Those products
with the highest percentage of active ingredient will
provide the highest degree of protection from biting
pests. Materials commonly used: diethyl meta-toluamide
(Deet), or dimethyl phthalate.
II. INSECTICIDE ACTIVE INGREDIENTS
Synergists - these are chemicals that "activate" some
insecticides and make them more poisonous to insects,
thereby enhancing the effectiveness of the active
ingredient. MGK 264 and piperonyl butoxide are two
commonly used synergists.
HAZARDS: those insecticides which contain piperonyl
butoxide should NOT be used in homes or other situations
where any person is using a prescribed medication for a
serious illness since this synergist effects the
production of liver enzymes, thereby causing
complications.
Pyrethrins (or synthetic pyrethroids - this is the
name used for those synthetic insecticides which
duplicate the botanical insecticide pyrethrum which is
derived from Chrysanthemum cinerariaefolium. Pyrethrins
are low in mammalian toxicity but quickly knock down
insect pests on contact. Pyrethrins are mainly used in
flying insect space sprays and they decompose rapidly in
fluorescent and natural light, leaving no residue.
HAZARD: asmatics and persons sensitive to pollen
should avoid inhaling pyrethrins since it may cause
allergic reactions.
d-trans-allethrin - this is one of the types of
synthetic pyrethrins, and is used to control flying
insects, often in combination with a synergist, and has a
quick knockdown effect.
resmethrin - this pyrethroid material is also used
in the control of flying insect pests and is especially
useful in controlling hard to kill flying insects such as
bees and wasps.
chlorpyrifos - this contact residual insecticide is
particularly effective against roaches. It does not kill
roaches upon immediate contact, but this delayed
mortality is more than compensated for by the long
residual life.
propoxur - this contact residual insecticide is also
effective against crawling insects, but does provide some
rapid knockdown in addition to the long residual life.
diazinon - this contact residual insecticide is
widely used for control of household, turf, ornamental
tree, and garden insect pests. Only premium grade (label
specifies indoor usage) should be used inside the home.
HAZARD: this is one of the more toxic substances
available to the homeowner for control of household
pests. It must be used with caution and in strict
accordance to label instructions.
malathion - this is another one of the commonly used
insecticides for control of pests in and around the home.
It has relatively low mammalian toxicity, however, the
residual life is not as long as some of the other contact
residual insecticides. Only premium grade malathion
should be used inside the home.
silica gel - is a nearly non-toxic material. The
silica abrades (rubs off) the waxy layer on the insect
cuticle, causing the insect to dehydrate and die
(provided the relative humidity is low enough). High
moisture will also cause the silica to lump together and
lose its effectiveness.
HAZARD: inhalation of the dust may cause severe
irritation.
boric acid - this material has limited use in some
ant and roach baits. It is a persistent, but slow-acting,
poison. Boric acid, USP, sold as an eyewash is safer to
use because of the lower concentration than the
insecticidal boric acid. Boric acid has been used as a
roach powder, but should only be lightly dusted into
cracks and crevices (NOT exposed surfaces) and SHOULD NOT
be used in homes with children.
HAZARD: Boric acid is acutely poisonous if ingested,
especially in infants and children.
arsenicals - these materials were once widely used as
insecticides, but owing to their high mammalian toxicity
they have been phased out of use. However, sodium
arsenate is still used in some ant bait traps and is
highly effective, but must be used with great caution.
HAZARD: HIGHLY TOXIC to all animals. Should not be
used in homes with pets or children.
paradichlorobenzene (PDB) - crystals and nuggets of
PDB are used as fumigants to repel or kill fabric pests
like clothes moths and carpet beetles. Fabrics put into
storage should be washed or dry cleaned and then stored
in sealed containers with PDB to prevent clothes moth or
carpet beetle damage.
HAZARD: DO NOT breathe the PDB fumes.
napthalene - flakes of this material are used in the
same manner as PDB.
N,N-diethyl-meta-toluamide (Deet) - is widely used as
an insect repellent for mosquitoes, biting flies, gnats,
no-see-ums, chiggers, ticks, and fleas. It is generally
formulated with ethyl or isopropyl alcohol. Those
repellents with the highest percentage of active
ingredient(s) (Deet or dimethyl phthalate) will be the
most effective.
HAZARD: Deet is a moderately toxic insecticide; it
may cause skin rashes.
dimethyl phthalate - is another commonly used insect
repellent, and is especially effective against
mosquitoes, fleas and chiggers. Unlike Deet, it is a
relatively non-toxic material.
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.
Read and follow instructions on the pesticide label.
Heed all warnings. Check with your physician if you have
any concerns regarding your personal health risk.