European cuckoo bees of the tribe Dioxyini (Hymenoptera, Megachilidae): distribution, annotated checklist and identification key

Altogether, ten species of cuckoo bees of the tribe Dioxyini have been recorded from Europe, with two species distributed widely in the continent while others are restricted in distribution to only one or several countries in southern Europe. These ten representatives are classified into five genera: Aglaoapis, Dioxys, Ensliniana, Metadioxys and Paradioxys. Dioxys atlanticus is reclassified from a subspecies to a valid species, and new occurrence records of this species are reported. New synonymy is established for Dioxys cinctus = D. montanasyn. nov. The distribution, morphology, ecology and hosts of all species were reviewed from both published and unpublished sources. New red-list categories for each species were created according to the new records of occurrence. An identification key including all ten species and photographs of their whole bodies and main identification characteristics was prepared, and distribution maps for all species were created.