Many gardeners like to control insects organically or naturally as much as possible to avoid dangers in handling pesticides and residues on plants. An increasing number of organic pesticides are becoming available for use.
Bacillus thuringensis (often referred to as B.T.) is a bacteria which causes disease in insects, especially caterpillars, within two days after they eat it. Recently formulations which are effective on beetles and grasshoppers have become available. B.T. is nontoxic to warm blooded animals. It is available in wettable powders and liquid concentrates under several brand names including Thuricide, Dipel, Biotrol and Attack.
Insecticidal Soap is produced from potassium salts of fatty acids and is effective in washing small insects and insect eggs off of plants. Most effective against aphids and mites.
Neem Oil is refined from the Neem tree and has proven effective for controlling a wide range of insect pests including mites. It also prevents spread of some plant diseases.
Paraffinic Oils are highly refined oils which can be used in warm weather and on green leaf tissue. Clove, thyme, and sesame seed oils are also sometimes used as insecticides.
Pyrethrum is a naturally occurring plant derivative contact insecticide with little residual action available in wettable powder and dust.
Rotenone is a natural plant derivative contact insecticide with little residual action available in dust form.