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Organic Pesticides

By Adrian Higgins
Washington Post Staff Writer
Thursday, May 10, 2001

Return to "Growing Green in the Garden"

PESTICIDE Brands Uses Application Pros/Cons

Horticultural Oil
(Active Ingredient: paraffin-based oil)

Bonide All-Seasons Horticultural Spray Oil, Sunspray Ultra-Fine Sprayed on ornamental shrubs and tress, including fruit trees, to smother and kill insect and mite pest eggs, larvae and adults. A weaker, 1 percent solution is used in the growing season, a stronger formulation during winter dormancy. Mixed with water in tank sprayer or used in hose-end sprayer. For best results, spray plants from all sides and on all leaf surfaces. Winter application can wipe out populations of beneficial insects.

Made from highly refined paraffin, horticultural oil is effective and environment- friendly. Pests cannot develop resistance to it the way they do to poison.

Food-Grade Horticultural Oil(Active Ingredient: canola or cottonseed oil)

Concern Pesticide Oil, Oil-Away sold by Gardens Alive! Considered even "greener" than petroleum-based horticultural oil. Controls such pests as aphids, leafhoppers, scale insects, leaf miners, whiteflies and mites. Hose-end sprayer or tank sprayer. Same as horticultural oil.
Neem Oil
(Active Ingredient: neem seed-oil extract)
Neem-Away, Shield All, Safer Bio-Neem, Green Light Rose Defense, Green Light Tomato & Vegetable Spray Repels or kills a range of insect pests and mites, particularly those in the vegetable garden. Affected pests include aphids, Japanese beetles, cucumber beetles, army worms, leaf miners, Mexican bean beetles, leafhoppers, weevils and whiteflies. Also used as a fungicide against powdery mildew.  Ready-to-use or concentrate mixed with water in sprayers. Regular spraying needed, especially as a fungicide. Effcts on pests not immediately seen. Unpleasant smell.
Hot Pepper Wax(Active Ingredient: capsaicin) Dragon Hot Pepper Wax, Bonide Hot Pepper Wax Repels insects. Ready to use spray bottle or concentrate Safe on food plants. Some reports of pepper  taste on vegetables sprayed repeatedly. Might repel rabbits and deer as well as insects.
(Active Ingredient: pyrethrin, a natural toxin from the pyrethrum plant)
Concern Multi-Purpose Insect Killer, Dragon Rotenone & Pyrethrin, Bonide Liquid Rotenone-Pyrethrin Spray, Schultz Roses and Flowers Insect Spray Broad range of insect pests Diluted with water for sprayer, or ready-to-use formulation Effective and rapid. Kills beneficials, including bees, wasps and butterflies.
(Active Ingredient: baccilus thuringiensis, a bacterium that disrupts the molting process of larvae)
Different strains have been developed for different pests. Kills pests in caterpillar stage, including cabbage worms, gypsy moths, Eastern tent caterpillars and mosquitoes. Dust, wettable powder or pond dunks Safe on food plants. The pest must be identified and attacked young for the best effect. Also kills the caterpillars of desirable butterflies.
Milky Spore (Active Ingredient: bacillus popiliae) St. Gabriel Laboratories Milky Spore Powder Infects and kills Japanese beetle grubs Powder to sprinkle on foliage Long lasting but slow acting. Bacterium may be inactive and useless. Targets only Japanese beetle grubs - other white grub pests are unaffected. Will not prevent adult beetles arriving from neighboring areas.
Insecticidal Soap (Active Ingredient: potassium salts) Concern Insect Killing Soap, Safer Insecticide Soap Kills soft-bodied pests. Marketed for use on edible plants up to day of harvest, as well as houseplants. Concentrate or ready-to-use Low toxicity, but might not be effective against mites or hard-bodied pests such as weevils.
Iron Phosphate Slug Control (Active Ingredient: iron phosphate) Escar-Go!, Sluggo Lures and kills mollusks Sprinkle around susceptible plants Safe to use around pets. Doesn't need constant attention like beer traps.

© 2001 The Washington Post Company