Biology and Predatory Potential of Predators on Bean Aphid

Studies on the biology of P. trinotatus on A. craccivora indicated that the lady bird beetle did not lay eggs on leaves under the laboratory condition when fed on A. craccivora. However, they were laid on under surface of the lid of the container near to the grooves. The average fecundity of the female was 142.76 ± 17.75 eggs.The average longevity of male and female was 26.40 ± 3.017 and 30.80 ± 2.515 days, respectively. Total life cycle occupied on an average of 50.78 ± 3.495 days by male and 55.18 ± 3.348 days by female. During entire life period of P. trinotatus consumed on an average 171.69 ± 13.17 aphids when reared on A. craccivora. Biology of C. carnea on A. craccivora revealed that the freshly laid eggs were stalked, oval and pale green in colour, which turned to dark grey prior to hatching. The average egg producing capacity of gravid female was found to be 509.96 ± 77.43 eggs/female. Total life cycle occupied was of 50.25 ± 4.389 days in male and 58.58 ± 3.357 days in female under the laboratory condition. A single predatory larva consumed on an average 397.32 ± 38.86 aphids during its developmental period.