ABSTRACT
The term "organophosphorus" has been loosely applied to all compounds containing carbon which are derivatives of an acid containing phosphorus. The study of the ester bond involving phosphoric acid led to the development of an entirely new group of insecticides of almost unlimited structural arrangement, physicochemical properties, and potency which demonstrate the ultimate in structureactivity relationships in attempts to produce potent and selective insect toxicity while minimizing the toxicity toward nontarget species. Accounting for some 45% of the registered pesticides in the U.S., there are some 200 different organophosphorus ester insecticides in the marketplace. For detailed descriptions of the development, chemistry, and nomenclature of this class of insecticides, the reader is referred to the early review by Holmstedt1 and the books of O'Brien,2 Heath,3 Melnikov,4 Fest and Schmidt,5 and Eto.6
