Pyrethrins/Pyrethrum: Botanically derived organic compounds that disrupt the nervous system along axons.

Repellant: Repels insects, mites, ticks, or vertebrate pests.

Residual Insecticide: A crystalline or film-like layer forms on treated surfaces where insects congregate or are expected to walk. The speed that the insect is affected and the length of time that the residual will persist on the surface vary with the active ingredient, type of formulation, surface it is applied to, and external conditions such as wind, rain, and humidity.

Resistance: If a pest population is repeatedly treated with the same insecticide and each new generation of insects has increasingly higher tolerance, a “resistant” strain of insects is produced.

Soil Sterilant: A chemical that prevents the growth of all plants and animals in the soil. Soil sterilization may be temporary or permanent, depending on the chemical.