Prey preference of an aphidophagous ladybird, Coccinella transversalis (Coccinellidae: Coleoptera) on two aphid species

Abstract

Prey Preference of adult male and female, Coccinella transversalis (Fabricius) was studied when fed on aphids, Aphis craccivora (Koch) and Aphis gossypii (Glover), which sequester toxic allelochemicals from their host plants. Adult males and females of C. transversalis prefer to consume A. gossypii over A. craccivora in most mixed diet combinations (cafeteria setup). This was strongly supported by significantly high values of β and C prey preference indices. However, when provided with A. craccivora and A. gossypii separately, we found a similar reluctant behaviour in the adults. The adults showed no significant difference in aphid consumption, regardless of the species of aphid and the sex of the adult ladybird. Therefore, we conclude that host plant allelochemicals/ toxicants have a direct effect on the prey preference of ladybirds. Mixing two toxic similar diets can make one diet more suitable than the other.