The effects of different aphid foods on Adalia bipunctata L. and Coccinella 7‐punctata L

SUMMARY The influence of different aphid foods on larval development and adult fecundity of Adalia bipunctata L. and Coccinella 7‐punctata L. was investigated. Certain aphids such as Myzus persicae Sulz. and Acyrthosiphon pisum Harris were suitable for both species. Megoura viciae Buckt., was toxic to A. bipunctata but not to C. 7‐punctata. Aphis fabae Scop., although a common natural prey of A. bipunctata, slowed larval development, partly because it was nutritionally unsuitable. Fecundity of adults fed on A. fabae was also reduced to less than half. Larvae and adults of C. 7‐punctata developed and reproduced as well on A. fabae as on other suitable aphids. C. 7‐punctata caught aphids more quickly than A. bipunctata. Larvae of both species given relatively unsuitable prey fed more slowly than normal and consumed less of each aphid. The toxic aphid M. viciae was rejected by A. bipunctata after a short period of feeding.