Key to long horn bee species of the tribe Eucerini (Hymenoptera, Apoidea, Apidae) occurring in Europe

Europe hosts some 2180 wild bee species, representing ca 10% of the world bee diversity. The long horn bee tribe Eucerini (Hymenoptera, Apidae) is one of the most charismatic groups in this region, and is particularly diverse in the southern, Euro-Mediterranean region. While identification of most species is difficult, a comprehensive identification tool has largely been missing, but is essential for current monitoring programs. This work presents the first modern comprehensive key to species of the tribe Eucerini in Europe. Keys are provided separately for females and males, including 89 out of the 112 species of Eucerini listed in the most updated checklist of the bees of Europe. The keys comprise new morphological delimitations for numerous species, particularly in the female sex, to resolve gaps in species identification, including some long known and widely distributed species. In addition, species are presented in the keys in context of genera, subgenera, and previously recognised species groups, when this is possible.