Effect of Temperature and Solvent on the Toxicity of DDT against the Common House Fly

Abstract

A 2³ factorial experiment on alternative storage conditions for insects before and after treatment and the adjuvant effect of soy bean oil to solvent in topical application was designed to test toxicity of p, p'-DDT against the common house fly, Musca domestica vicina MACQUARDT. The house flies were stored in either at 30°C or 20°C for 24 hours before treatment, and also in either 30°C or 20°C for 24 hours after treatment. Soy bean oil was used as a 2 per cent (v/v) solution in acetone. As is seen in the estimated relative dosage values or relative potencies shown in Table 6 or 7, among the three factors concerning the toxicity of p, p'-DDT against the common house fly, the effect of storage temperature after treatment was much bigger than that of storage temperature before treatment, and the adjuvant effect of soy bean oil was the smallest. The toxicity of DDT in lower temperature was bigger than that in higher temperature, and it was verified from this experiment that the temperature coefficient of the lethal action of DDT to insect is negative for some range of temperature. The adjuvant effect of soy bean oil added to acetone was also recognized to some extent.