Division of Entomologyl, Central Potato Researcb- Institute, Shimla-171001, H.P.
Field-cum-laboratory experiments were conducted during main summer crop seasons of 1982 and 1983 at the farm of Central Potato Research Institute, Shimla (H.P.) for evaluating the relative residual toxicity of contact insecticides as sprays against the grubs and adults of Henose-pilachna (Epilachna) ocellata Redt. on potato crop. Insecticides were applied at 0.05 per cent concentration@ 1250 litres of spray to the field crop/ha. Leaves were detached at different inter-vals and laboratory assay made of toxicity to grubs and adults of H. ocellatta. Chlorpyrifos, quinalphos, carbaryl + molasses and dicrotophos registered greater mortality for longer duration than other insecticides during both the years against the grubi and adults.
