Effect of Mineral Oil Solvent on the Toxicity and Speed of Action of Malathion

Busvine 1 and Barker and Rawhy 2 reported that solutions of DDT in mineral oils are more toxic to DDT-resistant houseflies than solutions in acetone, although for normal susceptible fly strains acetone solution was about four times as toxic as the oil solution. MacCuaig and Watts 3 found that a 3.5–5 per cent solution of DDVP in mineral oils (KEB and LPD) was about twice as toxic to desert locusts as the concentrated 35 per cent solutions in the same oils. We have found a relationship between the toxicity, speed of action and the concentration of malathion ( S -(1,2-di(ethoxycarbonyl) ethyl) dimethyl phosphorothiolothionate) solutions in KEB. The results of our experiments are presented in this communication.