Colonization behaviour and parasitization by Ephedrus cerasicola (Hym., Aphidiidae) in choice studies with two species of plants and aphids

Abstract

AbstractExperienced females of the aphid parasitoid Ephedrus cerasicola Stary were released into a glasshouse compartment or into a cage, where they could choose between an equal number of cucumber and swede plants. The plants were uninfested in some experiments, or cucumbers were infested with Aphis gossypii Glover and swedes with Myzus persicae (Sulzer). The parasitoids were reared on M. persicae on swedes. In all experiments, both with uninfested and infested plants, the females colonized the cucumber plants much more frequently than the swedes. Also mummy production was higher on the cucumber plants.In some additional cage experiments with a single infested plant (no choice), A. gossypii on cucumbers were more parasitized than M. persicae on swedes in three of four experiments.The results indicate that even if E. cerasicola is reared on M. persicae/swedes, parasitoid females released into a cucumber glasshouse will probably readily spread to the cucumber plants and parasitize A. gossypii there.