Parasitoids and hyperparasitoids of cereal aphids (Homoptera, Aphididae) on winter wheat in Slovakia

In 1997-1998 the species composition of the community of cereal aphid primary parasitoids and hyperparasitoids on milky stage winter wheat was examined at nine sites in Slovakia. In 1997, 151 of all hymenopteran parasitoids were primary parasitoids and 418 were hyperparasitoids. In 1998, 159 individuals were primary parasitoids and 161 hyperparasitoids. In total, eight primary parasitoid species (Hymenoptera, Braconidae) were detected: Aphidius ervi, A. rhopalosiphi, A. uzbekistanicus, A. picipes, Praon volucre, Praon sp., Ephedrus plagiator and Diaeretiella rapae. Species of the genus Aphidius were most abundant in both years except A. picipes, which was not recorded in 1997, whereas Praon sp. was not recorded in 1998. In 1997, A. ervi was significantly more abundant than the other species except A. rhopalosiphi and A. uzbekistanicus where the difference was non-significant. In 1998, A. uzbekistanicus was significantly more abundant compared to the other primary parasitoids, except A. ervi and A. rhopalosiphi. Hyperparasitoids of four genera were detected: Dendrocerus sp. (Hymenoptera, Ceraphronidae), Alloxysta sp. (Hymenoptera, Cynipidae), Asaphes sp. (Hymenoptera, Pteromalidae) and Coruna sp. (Hymenoptera, Pteromalidae). Dendrocerus sp. was most abundant in both years. The highest abundance df parasitoids was detected at the Nitra and Spissky Hrad sites in 1997 and at sites Neded and Batka in 1998.