For example, silica aerogels affect the entire lipid layer on the insect cuticle. Although most insecticides have multiple biological effects, toxicity is usually attributed to a single major effect. This fact sheet is intended to explain what insecticides do in insects to cause toxicity and death. However, many insecticides belong to more than one category when grouped in this way, limiting its usefulness. Another way insecticides can be classified is by their mode of action.
Most insecticides affect one of five biological systems in insects.
This method of classification is preferred among scientists. Most traditional insecticides fit into this category. Pyrethroid, organophosphorus, and carbamate insecticides all adversely affect the nervous system. Pyrethroids are synthetic chemicals whose structures mimic the natural insecticide pyrethrin. These insecticides have a unique ability to knock down insects quickly.