The Potency and Persistence of some new Synthetic Insecticides

Abstract

Simple laboratory methods are described for assessing the potency and persistence of insecticides. Some of the newer synthetic insecticides have been tested by these methods against seven arthropod pests of medical importance.Initial potency was judged by the mortality of insects exposed to standard films of oil solutions of the compounds, on filter papers. The approximate order of potency of the samples tested was:—γBHC>dieldrin>aldrin=pyrethrins>chlordane=DDT= “Pyrolan” =allethrin> toxaphene.Residual action was judged by the mortality of batches of bed bugs exposed to films of the insecticides, at intervals up to six months after preparation. The approximate order of persistence was:—dieldrin=DDT=toxaphene>“Pyrolan”>γBHC=chlordane=aldrin>allethrin, pyrethrins.