“Organic insecticides can be divided into several classes [1]: the chlorinated hydrocarbons such as 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, better known as DDT, and lindane, the organophophorous derivatives, including compounds such as parathion and malathion, and the pyrethroids, which are similar in structure to the naturally occuring pyrethrins, which are also insecticides.”