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 prima ry parasitoids and hyperparasitoids on milky stage winter wheat was examine d at nine sites in Slovakia. In 1997, 151 of all hymenopteran parasitoids w ere primary parasitoids and 418 were hyperparasitoids. In 1998, 159 individ uals were primary parasitoids and 161 hyperparasitoids. In total, eight pri mary parasitoid species (Hymenoptera, Braconidae) were detected: Aphidius e rvi, A. rhopalosiphi, A. uzbekistanicus, A. picipes, Praon volucre, Praon s p., Ephedrus plagiator and Diaeretiella rapae. Species of the genus Aphidiu s were most abundant in both years except A. picipes, which was not recorde d 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 prima ry parasitoids, except A. ervi and A. rhopalosiphi. Hyperparasitoids of fou r genera were detected: Dendrocerus sp. (Hymenoptera, Ceraphronidae), Allox ysta sp. (Hymenoptera, Cynipidae), Asaphes sp. (Hymenoptera, Pteromalidae) and Coruna sp. (Hymenoptera, Pteromalidae). Dendrocerus sp. was most abunda nt 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.