Suitability of Five Prey Aphid Species for Development, Fecundity and Survival of the Predators Coccinella septempunctata (L.) and Harmonia axyridis (Pallas) Under Laboratory Conditions

The developmental time, larval survival and fecundity of Harmonia axyridis Pallas and Coccinella septempunctata (L.) reared on Acyrthosiphon pisum Harris, Aphis fabae Scopoli, A. craccivora Koch, Schizaphis graminum Rondani, Rhopalosiphum padi (L.) were studied under laboratory conditions (22±1°C, 70±5% r.h. and 16:8 hours dark:light photoperiod). C. septempunctata and H. axyridis larvae took shorter time to develop to pupal stage when they fed on S. graminum and A. craccivora than when fed on the other three species. There was no significant effect of aphid species on the sex ratio. Adult C. septempunctata and H. axyridis from larvae reared on A. pisum and S. graminum weighed more than adults reared on the other aphid species. Fecundity of H. axyridis and C. septempunctata was significantly higher when reared on A. pisum (1461±115.04 and 1992±124.80 eggs/ female, respectively) than on the other aphid species. There was no significant effect of aphid species on the longevity of C. septempunctata and H. axyridis adults. A. pisum and S. graminum seem to be the most suitable hosts for C. septempunctata and H. axyridis, and should be used in rearing these two predators