Influence of prey species on immature survival, development, predation and reproduction of Coccinella transversalis Fabricius (Col., Coccinellidae)

Six aphid species, viz. Aphis craccivora, Aphis gossypii, Aphis nerii, Myzus persicae, Lipaphis erysimi and Uroleucon compositae were provided as prey to the feeding stages of Coccinella transversalis (Fabricius). All of them were found to be essential prey, however the relative prey suitability varied. All the predatory stages of C. transversalis consumed and preferred A. gossypii, the most and A. nerii, the least. Significant effect of prey quality was observed on pre‐imaginal developmental periods, wet weights and adult longevity. The complete development was shortest on A. gossypii (13.01 ± 0.18 days) and longest on A. nerii (20.51 ± 0.25 days). The total prey consumption by larva, adult male and female in their lifetime was maximum (665.30 ± 5.75, 4831.10 ± 123.54 and 5412.30 ± 94.51, respectively) on A. gossypii and minimum (434.80 ± 4.03, 802.80 ± 34.37 and 905.20 ± 52.48, respectively) on A. nerii. Immature survival, growth index and adult emergence of C. transversalis was maximum (68.33, 7.82 and 88.21%, respectively) when larval instars consumed A. gossypii and minimum (37.75, 2.18 and 60.69%, respectively) after feeding on A. nerii. Female reproduction was also prey quality dependent showing maximum reproductive performance in terms of fecundity and percentage viability, with a highest reproductive period and lowest non‐reproductive period on A. gossypii, followed by A. craccivora, L. erysimi, M. persicae, U. compositae and A. nerii. Regression analysis revealed a positive correlation between: (1) daily prey consumption and relative growth rate, (2) adult weight and developmental rate, (3) weights of adult male and female, and (4) female longevity and fecundity.