Residual toxicity of some important insecticides to the adults of Lipaphis erysimi (Kalt.) (Aphididae: Hemiptera)

On the basis of LT50 values, amongst the different insecticidal concentrations used for mustard seed treatment to protect the plants against Lipaphis erysimi Kalt, monocrotophos 2.5 per cent formulated from technical grade (T.G.) as also emulsifiable concentrate (E.C.), phosphamidon 1.0 per dent (E.C.) and 2.5 per cent (T.G. and E.C.), lindane 5.0 per cent (T.C. and E.C.), phospbamidon 1.0 per cent (E.C.) and carbosulfan 3.0 per cent soluble powder (S.P.) were more or less the same and afforded the protection up to 33–34 days. However, lindane 1.0 per cent (T.C. and E.C.) and monocrotophos 0.5 per cent V.G. and E.C.) remained effective for relatively shorter duration (29–30 days).