The fate of released parasitoids (Hymenoptera: Braconidae, Aphidiinae) for biological control of aphids in Chile

Abstract Research on aphid-parasitoid associations was carried out in Chile in 1979–80 and 1991–92 on the biological control of the cereal aphid pests Metopolophium dirhodum (Walker), Sitobion avenae (Fabricius), and Diuraphis noxia (Mordvilko). The introduced parasitoid species, Aphidius ervi Haliday, A. rhopalosiphi De Stefani Perez, A. smithi Sharma & Subba Rao, A. uzbekistanicus Luzhetski, Ephedrus cerasicola Starý, E. nacheri QuilisPerez, E. plagiator (Nees), Monoctonus nervosus (Haliday), Prnon gallicum Starý, P. volucre (Haliday) were all recovered in cereal and other ecosystems. Most of the parasitoids had adapted well and some of them had even extended their host range; ecological relationships were all found to extend beyond those of the target pests. The parasitoid complex, which had developed from the indigenous and introduced species, was found to be successful in preventive biocontrol and the endemic fauna of Chile was not affected.