Vol. 20, No. 1, 2000 Pesticides and You Page 19Beyond Pesticides/National Coalition Against the Misuse of Pesticides

atmosphere, it does not have the dangers associated with the useof synthetic pesticides.

Electrical currents can be used to kill insects that nest in thewalls of a structure. The ElectorgunTM uses low wattage, highvoltage, and high frequency to kill the insects. It does not emitmicrowaves, x-rays, ultraviolet rays or other potentially harmful

radiation. Tests have shown thegun to be very effective. Exist-ing pest holes and holes drilledinto the nests by the operator areused as entry points for the elec-tricity. Tests show that whereassome termites die immediately,others may take weeks to die, butthat they all die eventually.

Fatty-acid soap and watercan be used to control pests. The fatty acids in soaps serve as aninsecticide killing pests on contact. Aphids, which attract ants,can be controlled by treating the aphids directly with insecti-cidal soaps. Direct action against individual fire ant nests in-clude pouring boiling or soapy water directly into the hole.

Beneficial nematodes are microscopic soil-dwellingworms that actively search for insects like pre-adult fleas, fireants, or termites in the yard. After invading the larvae or pu-pae, they release a bacterium that kills the host within 48hours. The nematodes then feed on the pest’s body, repro-duce and seek out more pests. When all larvae and pupae arekilled, the nematodes die off and biodegrade. Numerous pestproblems can be controlled or eliminated by using biologicalcontrols that have a minimal impact on non-target speciesand offer long-term solutions.

Milky spore disease, Bacillus popilliae is a nontoxicway to control grubs. Commercial milky spore dust is madeby inoculating beetle grubs with the disease and then ex-tracting the spores, which resemble dust or powder whendry. The spores can be applied any time except when theground is frozen or a strong wind is blowing. Grubs be-come infected when they feed on the thatch or roots ofgrass where the spores have been applied. As the infectedgrubs move about in the soil, then die and disintegrate,they release one or two billion spores back into the soil.This spreads the disease to succeeding generations of grubs.If the conditions are right, grub population high and feed-ing vigorously, and soil is at least 70 degrees F and verymoist, the disease can spread through the grub populationin a week or two. In general, however, the disease shouldnot be thought of as a quick knockdown insecticide. It maytake a season or two before it has a substantial impact.

Chlorpyrifos, the active ingredient in over 800 pesticide products, is used to control numerous pest problems. When looking for alternatives to using this chemi-

cal you must remember that one chemical cannot be swiped outfor another. In order to identify an alternative to usingchlorpyrifos it is necessary to first identify the pest problem.

It is important to rememberwhen controlling a pest problemto look for long-term solutionsnot just a temporary control. In-stead of addressing the cause ofpest problems, many pesticidesonly treat the symptoms, withoutchanging the structural problemsthat create an environment con-ducive to their existence. Pesti-cides are often ineffective over the long term and the most com-mon pests are now resistant to many insecticides.

Simple changes in your environment can significantly reducepest populations. Before reaching for a pesticide, monitor thepest population, make structural repairs, use proper sanitationinside and outside, and modify the pest’s habitat. Any openingsthat pests are using to access the structure should be caulked,screened or repaired. Some outdoor pests are attracted to spilledgreasy or sugary liquids, improperly stored garbage, untendedpet foods or explosions of naturally-occurring food sources likeaphids or scale infestations on nearby plants. Efforts to elimi-nate food sources may eliminate the pest problems.

Following is a brief description of some alternatives to usingchlorpyrifos to control common pest problems. Use Table 1 toidentify which alternatives can be used to eradicate a specificpest problem.

Non-Toxic SolutionsNon-Toxic SolutionsNon-Toxic SolutionsNon-Toxic SolutionsNon-Toxic SolutionsHeat treatments are effective in controlling pest popula-

tions for those pests that have minimum and maximum tem-peratures beyond which they cannot survive. Heat treatmentsrequire raising the temperature of a structure to 120 degreesF or more. Special equipment composed of a heating unit,blowers and ducts carries the heat to the locations in the struc-ture where the pests are causing damage. Heat treatment fieldtests have killed insects inside wood without damaging thebuilding or furnishings, although certain sensitive appliancesshould be removed as a precaution.

Cold treatments of liquid nitrogen can also eradicate peststhat live in a narrow temperature range. Liquid nitrogen can bepumped into walls, which freezes the pest, killing them, thenwarms and evaporates. Because nitrogen is a natural part of our

Alternatives to Using ChlorpyrifosBy Kagan Owens

The LowDown on Dursban • The LowDown on Dursban • The LowDown on Dursban • The LowDown on Dursban

It is important to rememberwhen controlling a pest problemto look for long-term solutionsnot just a temporary control.

Page 20 Pesticides and You Vol. 20, No. 1, 2000Beyond Pesticides/National Coalition Against the Misuse of Pesticides

Bacillus thuringiensis (B.t.) is a naturally occurring soilbacterium; it is a spore-forming rod and an insect pathogen.Different strains are toxic to particular kinds of insects. Thereare nearly 400 registered products that have been marketedin the country, providing effective control of such major in-sect pests as gypsy moths, mosquitoes, blackflies, and manyothers. These B.t. strains are only effective against insects intheir larval feeding stages, since B.t. must be ingested to beeffective. Depending on how much B.t. is ingested, insect larvasoon stop feeding andare dead in a few daysto a few weeks. B.t. iscompletely biode-gradable, and doesnot persist in the di-gestive systems ofbirds or mammals.There is no evidencethat B.t. goes on to re-produce in the wild.B.t.’s short biologicalhalf-life and high specificity makes the development of fieldresistance much more unlikely than with chemical pesticidesif used in a targeted fashion.

Least Toxic PesticidesBecause of the high toxicity of conventional pesticides and

the high levels of exposure to people and pests that result fromtheir use, it is wise to avoid them. Pesticides are products thatare designed to kill living organisms and should be treated withcaution. If pesticides are used, it is best to go with baits or crackand crevice spot treatments and use the least toxic pesticide avail-able and only after non-toxic alternatives have been tried.

Boric Acid is a low-toxicity mineral with insecticidal proper-ties. It does not evaporate or volatilize into the air or pose theconsiderable health concerns associated with synthetic pesticides;however it can still pose health hazards and should be used withcare. Insects travel through the boric acid, which adheres to theirlegs. When the insects groom themselves, they then ingest thepoison, which causes death three to ten days later of starvationand dehydration. As long as the material is not allowed to be-come wet, its continuous presence ensures that hatching insects,which sprays commonly spare, are exposed and die. Becauseboric acid is a stomach poison, don’t expect immediate results –it may take weeks or even months to completely get rid of thepest problem. While boric acid is somewhat slower acting thanthe synthetic pesticides, like chlorpyrifos, diazinon, or pyrethrins,it is highly effective over a long period of time. At least one studyhas shown that the combination of heat, 110 degree F for twohours with boric acid, will increase the speed at which the Ger-man cockroach is killed. As with any pesticide, keep boric acidpesticide products out of reach of children and only use it inlocations where it will not come in contact with people or ani-mals, such as in cracks and crevices, behind counters, and inbaseboards.

Diatomaceous earth and silica aerogels are insecticidal duststhat kill pests by breaking through their outer cuticle, whichprotects them from excess moisture loss. When the dust comesin contact with the pest, it abrades their outer shell, dehydratingand finally killing the pest. Because the dusts are inorganic, theycan remain effective for a very long time. Although they are madeof inert material and are relatively safe, care should be taken toavoid inhalation. Be aware that they have been combined withpyrethrin insecticides in various products; and there are serious

health concerns asso-ciated with the use ofpyrethrins. With diato-maceous earth, it is im-portant that natural,not swimming poolgrade, be used. Swim-ming pool grade hasbeen refined in such amanner that makes itmore harmful to hu-man lungs. Silica

aerogels are higher in acute toxicity and tend to kill insects morequickly than diatomaceous earth. Silica aerogels are toxic to fish,so they should not be applied where they could run off into astream, pond or lake.

Botanical pesticides are derived from plants that areknown to have insecticidal properties. It is important to re-member that just because a pesticide is derived from a plantdoes not mean that it is safe for humans and other mammalsor that it cannot kill a wide variety of other life. Many botani-cal insecticides are formulated with synergists. These haveno insecticidal effect of their own, but serve to enhance theinsecticidal effect of the botanicals. Carefully read the labelson all products before use to make sure that they do not alsocontain toxic pesticides. Some botanical pesticides can be quitetoxic to humans and should not be used. Neem oil and garlicoil are two least-toxic botanical pesticides listed below. Oth-ers that can also be used as a last resort are citrus oils, mintoil, pine oil and herbal extracts.

Neem oil, extracted from the tropical neem tree, containsinsecticidal properties that are composed of a complex mix-ture of biologically active compounds. It has a strong, unpleas-ant odor and a bitter taste. Its various active ingredients act asrepellents, feeding inhibitors, egg-laying deterrents, growthretardants, sterilants and direct toxins. Neem has both contactand systemic action in plants. The active ingredients biode-grade rapidly in sunlight and within a few weeks in the soil.

Garlic oil exhibits antibacterial, antifungal, amebicidal andinsecticidal qualities. Although garlic oils kill pest insects andsome pathogens, it also kills beneficial insects and microbes.Thus, it is not recommend as an all-purpose spray for out-door use.

If you have a pest problem, contact Beyond Pesticides/NCAMPfor a detailed information packet on how to control the pest usingnon and least toxic methods.

The LowDown on Dursban • The LowDown on Dursban • The LowDown on Dursban • The LowDown on Dursban

If pesticides are used, it is best to go with baits or

crack and crevice spot treatments and use the least

toxic pesticide available and only after non-toxic

alternatives have been tried

Vol. 20, No. 1, 2000 Pesticides and You Page 21Beyond Pesticides/National Coalition Against the Misuse of Pesticides

The LowDown on Dursban • The LowDown on Dursban • The LowDown on Dursban • The LowDown on Dursban

AntsHeat treatmentCold treatmentElectrical currentFatty acid soapBeneficial nematodes, Steinernema sp.SpinosadDiatomaceous earthBoric acidBotanical pesticides: d-limonene, mint oil, herbal ex-tracts, orange oil, pine oil, garlic

Chinch BugBeneficial fungus, Beauveria spp.Beneficial wasp, Eumicrosoma beneficumInsecticidal soapSilica aerogel

CockroachesElectrical currentsHeat treatmentBeneficial fungus: MetarhiziumanisopliaeDiatomaceous earthBoric acidBotanical pesticides: orange oil, mint oil, herbal oil,neem

CricketsBeneficial fungal pathogen: Beauveria bassianaInsecticidal soapDiatomaceous earthBoric acidBotanical pesticides: neem

FleasBeneficial nematodesInsecticidal soapBoric acidDiatomaceous earthSilica aerogelBotanical: limonene and herbal oil extract

FliesBeneficial nematodes, parasitoids, parasitic mitesBotanical repellentsDiatomaceous earthSilica aerogels

Gypsy mothsMicrobial insecticide: Bacillus thuringiensisSpinosad

Japanese beetles/grubsMilky sporeBeneficial nematodesBotanical pesticides: neem

MosquitoesCarbon dioxide trapsBat housesPurple martin housesMicrobial insecticides: Bacillus thuringensis Israeliensis,and Bacillus sphaericusMosquito fish, Gambusia affinisBotanical pesticides: herbal extracts, neem

TermitesHeat treatmentCold treatmentTermite shieldElectrical currentsBeneficial nematodes, Steinernema carpocapsaeMicrobial termiticide: Metarhizium anisopliaeSpinosadDiatomaceous earthSilica gelBoric acidBotanical pesticides: neem

Wasp and HornetsPhysical trapsInsecticidal soapBoric acidDiatomaceous earthSilica aerogelsBotanical oil: mint oil

Webworms/Cutworms/CaterpillarsBeneficial NematodesMicrobial insecticide: Bacillus thuringiensisSpinosadBeneficial Endophytic fungiInsecticidal soapsFree roaming chickens

Table 1. Non- and Least Toxic Alternatives to Using Chlorpyrifos