Botanical and organic pesticide options are available for those who wish to reduce the use of chemical-based pest solutions.
Always check to see if any organic compound will harm other plants or animals. Unlike chemicals, where the bugs fall away after spraying, some organics are slow acting, so don't always expect instant gratification.
Synthetic pesticides often include additives which allow the product to remain active for extended periods of time. Because of the absence of these additives in organic products, they may require more frequent applications.
Remember too that even though a pesticide is considered natural or organic in origin, it isn't automatically classified as safe for humans. Some organic compounds may be toxic and dangerous to mammals (including humans), fish, birds, bees and other beneficial insects.
Here's a brief list of some more common organic pesticides:
Bacillus Thuringiensis - Also called Bt, a bacterium that kills insects in their larval stage (such as caterpillars). There are several strains to choose from depending on the pest you wish to control. It must be ingested by the pest to work. Bt is harmless to virtually all other creatures.
Botanical Extracts - Oils are extracted from spices and fruits, and then combined to deal with pests. They pose no danger to people or pets.
Corn Gluten - Corn gluten is a by-product from the manufacturing of cornstarch. It is also a growth inhibitor that effectively controls weeds. Corn gluten kills the roots of newly sprouted seedlings, making it safe around established plants.
Diatomaceous Earth - The crushed exoskeletons of microscopic marine and freshwater organisms are harmless to almost all living creatures. The exceptions are soft-bodied pests when they crawl across an area treated with the product. The particles of earth are like microscopic bits of broken glass that scratch, tear and destroy the bodies of the pests.
Horticultural Oil Sprays - These are light, petroleum-based oils used to control fungus and pests. The target must be soaked for effective treatment. Toxicity is low, but these oils may irritate skin or eyes.
Insecticidal Soap - A virtually nontoxic mixture of soap, oil and water used to deal with soft-bodied insects. Plants must be thoroughly soaked in order for soaps to be effective. (Do not use household soaps containing detergent on plants.)
Milky Spore - A bacteria that attacks Japanese beetles in their larval stage, milky spore is nontoxic to other organisms. Once established in the soil, it lasts for years.
Neem - Neem is an oil extracted from the neem tree, a tropical plant. It has low toxicity. Mixed with water, neem is used as an insecticide, fungicide and miticide.
Sulfur and Lime-Sulfur - Inorganic, non-chemical elements that are used to control mites and some foliar diseases.