Abstract

                                Two coccinellid predators, Menochilus sexmaculata (Fabricius) and Verania vincta Gorham were reared on three species of aphids, Aphis craccivora Koch on cowpea and beans, Lipaphis erysimi (Kalt.) on mustard and cabbage and Aphis gossypii Glover on brinjal. Marked difference in growth and development of the predators was observed when reared on different aphids and the same aphid infesting different crops. Size and fecundity of both the predators were greater when reared on A. craccivora (cowpea), M.sexmaculata developed faster on A.craccivora (cowpea) while Vvincta on L. erysimi (cabbage). Irrespective of the host aphid, the females of both the predators were bigger in size and also survived longer than males. M.sexmaculata prefers Lerysimi on cabbage than on mustard. Longevity of both adult predators was increased when fed on ten per cent sucrose followed by honey solution. But they failed to lay egges when fed on artificial foods.

Key words : Coccinellids, predators, aphids, host plants, biology