Insecticidal and neuroexciting actions of DDT analogs

The neuroexciting activity of DDT and its analogs to produce repetitive responses on the nerve cord of Periplaneta americana was determined using the extracellular electrode method. The convulsive activity on P. americana and the insecticidal effect on Callosobruchus chinensis were also examined. It was found that the convulsive and insecticidal activities increase almost proportionally with increase in the neuroexciting activity within a set of p,p′-substituted DDT analogs. The intimate connections among these biological effects suggest that symptoms such as convulsion and death caused by DDT analogs are closely related with their neuroexcitory effect and there is a common mode of action in spite of differences in insect species.