Nutrition ecology of Ascogaster quadridentata (Hymenoptera, Braconidae) and its host in apple orchards

Summary

The codling moth, Cydia pomonellaL. (Lepidoptera, Tortricidae) is the key pest in apple growing worldwide. Its increasing resistance against various insecticides, including granulosevirus based plant products, initiate the search for supporting tools for natural control, e.g. the activity of parasitoids. The Chelonine species Ascogaster quadridentata, an egg-larval parasitoid, does not host-feed, but requires sustainable access to sugar resources for nutrition. In the framework of the European CoreOrganic Plus project EcoOrchard (http://coreorganicplus.org/researchprojects/ ecoorchard/)weestablished flowering strips in the rows between trees with the aim to support natural enemies. In adjacent laboratory tests we explored which kind of flowering plants and sugars can be used by this parasitoid species.
Furthermore we investigated whether also the codling moth couldprofit from the provision of these floral resources. The results will help to give recommendations to growers how they can maintain a targeted floral diversity which support the activity of natural enemies, but not of pests.