A simple method for assaying contact toxicities of insecticides,with results of tests of some organic compounds against Calandra granaria L

A simple method of testing the contact action of insecticides either as residual dry deposits or as oil films is described. Tests with crystalline deposits of D.D.T. indicated that this method of assay was not sufficiently sensitive for practical use, but tests with oil films could be used. Some of the factors governing the toxicity of D.D.T. in the two systems are discussed, and the results of tests with several organic compounds are given.