Pyrethrin

The pyrethrins are a pair of natural organic compounds normally derived from Chrysanthemum cinerariifolium that have potent insecticidal activity. Pyrethrins are neurotoxins that attack the nervous systems of all insects. When present in amounts not fatal to insects, they still appear to have an insect repellent effect. Pyrethrins are gradually replacing organophosphates and organochlorides as the pesticide of first choice. They are non-persistent, being biodegradable, and break down on exposure to light or oxygen. The chemical structure of pyrethrins inspired the production of a variety of synthetic insecticides called pyrethroids such as bifenthrin, permethrin, and cypermethrin.