Phylogenetic analysis of molecular sequence data, crossing studies, host associations, and quantitative morphometrics indicate that there are at least six species in the Aphelinus varipes species complex in Eurasia. Here we concentrate on matching up these species concepts with available names in the taxonomic literature. By comparing voucher specimens with a character matrix developed from the literature we were able to match each cryptic species with an available name. The species we recognize in Eurasia are Aphelinus varipes, hordei, albipodus, kurdjumovi, atriplicis and certus. Some of these species appear to be host specific, others are generalists. The results have direct implications for biological control projects directed against aphids. For example, the species widely imported and established in North America for biological control of Diuraphis noxia is A. atriplicis.