Toxicity of insecticides to the cotton leaf worm moth. an electrophysiological [ETS] study

ABSTRACT

The present work, ETS records were carried out from the tarsal sesillum chaticum of the cotton leaf worm moth fore leg. The aim was to compare between the toxicity of carbamate, organophosphates [OPS], and pyrethroids insecticides of different concentrations. All records showed a concentration-dependent responses for all used insecticides. The toxic effects of carbamate and OPs appeared as hyperactivity followed by an excitation for several minutes and then convulsion and paralysis. This is believed to result from their inhibitory effects on the A cetylcholinesterase [AChE] and the ACh - receptor complex [AChR] which results in accumulation of the ACh at the cholinergic synapse inducing hyperpolarization, and thereby triggering repetitive action potentials of high amplitude followed by hyperexcitation which ultimately lead to death. The toxic effects of pyrethroids appeared as an increased depolarization and multiple nervous discharges which believed to result from their interference wit ion transport processes in the nervous tissue to the inhibition of the inactivation mechanism of Na* channels .The ETS records may be helpful in testing and comparing between the effects of these types of insecticides on the cotton, leaf worm moth by a method for from fields to estimate the minimum effective dose used. This leads to restoring the use of insecticides when necessary and decreasing the pollution of the environment