Development of resistance in the bean aphid, Aphis craccivora Koch. to various insecticides used for nearly a quarter century

The toxicity of commonly used insecticides was evaluated against Aphis craccivora Koch. to ascertain the trend of its susceptibility towards them. There has been a considerable shift in the level of susceptibility of A. craccivora to common insecticides after nearly a quarter century. The LC₅₀ values of malathion, dimethoate, phosphamidon, methyl demeton, lindane, pyrethrin, endosulfan, fenitrothion, metthyl parathion and nicotine sulphate increased 46, 28, 22, 21, 20, 15, 14, 12, 11 and 9 times, respectively. Amongst the three aphid species, Myzus persicae Sulz. was relatively resistant than A. craccivora to all the ten insecticides tested, whereas Lipaphis erysimi Kalt. was more susceptible than A. craccivora except to methyl parathion.