ABSTRACT
In order to be effective, insecticides have to make contact with and somehow enter the organism. Most insecticides are received by the target organism through contact with body surfaces although other routes such as ingestion or respiration are also used. In the case of systemic insecticides or of toxic baits, ingestion is the major route, and in the case of fumigant insecticides, inhalation is involved along with the body surface. In general, however, most insecticides are contact poisons. The insect contacts them as deposits on surfaces and as suspensions, solutions, or vapors in their aquatic or terrestrial environment. The cuticle is obviously one of the most important routes through which the penetration of insecticides occurs in insects because of their large proportion of cuticle surface. The efciency of the insecticide depends on its ability to penetrate through the insect cuticle to reach its target site.
