A few plant species that contain active insecticidal components have been commercially exploited. Pyrethrum, which is perhaps the most widely used botanical insecticide, is derived from the flowers of a plant in the genus Chrysanthemum, which belongs to the family Compositae.

Its active constituents are collectively called the Pyrethrins which are organic esters formed by the combination of two carboxylic acids and three keto alcohols. The combination of these components account for the kill and knockdown properties of Pyrethrum Extract.

The Pyrethrins are mainly concentrated in the flower head.