Field experiments were conducted during spring 1978 and 1979 at Central Potato Research Station, Jullundur (Punjab) for evaluating the relative efficacy of six foliar systemic insecticides viz. oxydemeton-methyl, dimethoate, thiometon, phosphamidon, monocrotophos and formoth on against the green peach aphid, Myzus persicae Sulzer, a potential vector of potato viruses. All tbe insecticides have been found significantly superior over control (water spray). However, oxydemeton-methyl and dimethoate gave the best results in keeping down the aphid popula1ion for a longer period. The insecticides were equally effective at 0.03% and 0.05% concentrations. It is, therefore, advisable to use 0.03% concentration of spray fluid instead of higher concentration of 0.05%. This will reduce the input cost and insecticidal hazard too.
