ABSTRACT
Organophosphorus insecticides (OPs) and carbamate insecticides are dealt with here in a single chapter because they share a common mode of action: cholinesterase (ChE) inhibition. Unlike DDT and most of the cyclodiene insecticides, they do not have long biological half-lives or present problems of biomagnication along food chains. When OCs such as DDT and dieldrin began to be phased out during the 1960s, they were often replaced by OPs or carbamates, which were seen to be more readily biodegradable and less persistent, although not necessarily as effective for controlling pests, parasites, or vectors of disease. They replaced OCs as the active ingredients of crop sprays, sheep dips, seed dressings, sprays used for vector control, and various other insecticidal preparations.
