Development and Feeding Potential of Scymnus sp. on the Bean Aphid Aphis craccivora

Scymnus spp. are well known predators of aphids in India. The biology and feeding potential of Scymnus sp. were studied in the laboratory at 28.2±1.2°C and 60.4±8.5 % R.H. on Aphis craccivora, a pest of Dolichos lablab. The egg, larval, prepupal and pupal stages occupied 4.44±0.26, 11.96±0.65, 0.93±0.23 and 6.18±0.36 days respectively. The larvae fed by sucking fluids from the appendages of the aphid prey. Unlike the grubs, tbe adults chewed and swallowed the aphids. The consumption of first, second, third, fourth Instar grub and adult was 4.62±0.22, 9.79±1.06, 12.06±0.58, 18.99±2.29 and 31.13±1.46 aphids per day respectively. The predatory grub consumed on an average 139.80±11.15 aphids during its development.