Stage-specific functional response of an aphidophagous ladybird, Coccinella septempunctata (Coleoptera: Coccinellidae), to two aphid species

Functional response of all instars, adult males and females of the ladybird Coccinella septempunctata L. was studied against two species of aphids, namely Lipaphis erysimi (Kalt.) and Brevicoryne brassicae L., infesting mustard and cabbage crops, respectively. The predatory stages of C. septempunctata exhibited a type II response on both the prey species. The attack rate was highest (0.0192) with the lowest handling time (7.9 min) when the adult female consumed L. erysimi. There was a significant difference in the predicted values of consumption of L. erysimi by fourth instars, adult males and females compared with those of B. brassicae, indicating that the former prey is preferred over the latter one. The adult females prey upon significantly more numbers of aphids than the adult males.