Three Major Groups of Insecticides:
Carbamates
Carbamate Insecticides are made from carbamic acid and are active against a wide variety of insects upon contact or ingestion. They work by inhibiting cholinesterase enzymes, which are essential for the nervous system to function. They are generally not as toxic, and some examples are aldicarb, methiocarb, and propoxur.
Chlorinated Hydrocarbons
Chlorinated Hydrocarbon insecticides are organic compounds containing chloride. They are broad spectrum insecticides that are slow to degrade, so are therefore in the environment or inside organisms for a long period of time. Many are now banned because of problems with their persistence and impact on the environment and humans/wildlife. DDT is one of the most well known chlorinated hydrocarbons, along with endosulfan and lindane which are still used today.
Organophosphates
Organophosphate insecticides are organic compounds that contain phosphorous, and were originally discovered from nerve gas. They more poisonous than the other types of insecticides and generally persist in the environment for a shorter amount of time than chlorinated hydrocarbons. They are not as widely available, but are replacing chlorinated hydrocarbons in agriculture. Some examples are methamidophos, dimethoate, and malathion.
