Insecticides Acting at the Cholinergic Synapse

The insect nervous system provides the preferred taget pool for all major insecticide classes (Fig. 8.28). Whereas the pyrethroids deregulate signal transduction by keeping the presynaptic sodium channel open for a prolonged period, the 8.28 The target of many carbamates inhibit reversibly and the phosphate esters irreversibly acetylcho- 

29 Striped Rice Stem Borer (Chilo suppressalis) (left) and Rice LeafroUer (Cnaphalocrocis medinalis) (right). 

Up to now, atotal of seven neonicotinoids have been commerdallylaimched (Fig. 8.31). [122] These can be divided into generational sub-classes with distinct strudural features. The adive compounds of the first generation contain a 6-chloro-3-pyridyl substituent, whereas the second generation agents share a 2-chloro-5-thiazolyl moiety. Dinotefuran is the first representative of the third generation, with a tetrahydrofuran-3-yl substituent. 

30 Insecticidal agents, which target at the cholinergic postsynapse. 

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