Action of Some Aliphatic Thiocyanates Against DDT-Resistant Strains of the House Fly

Abstract

It was found that ethyl and heptyl thiocyanate have relatively low toxicity and knockdown activity. In the lower thiocyanohydrins the insecticidal activity is increased. However, as contact insecticides against houseflies these substances are not very stable and several members of the series have a repugnant odor. Tetramethylene thiocyanohydrin liberates cyanide ions when injd. into rabbits. Upon esterification of the hydroxyl group of thiocyanohydrins with lower aliphatic acids, substances are obtained which show marked knockdown activity and toxicity for normal and DDT-resistant flies, when tested as contact insecticides. The esters thus formed are stable, without undesirable odor and of relatively low toxicity for mice. The pro-pionic and butyric acid esters of thiocyanohydrins of the formula HO(CH2)nSCN (n = 2,3,4) combine the highest knockdown and killing capacities.