Osmia (Melanosmia) bulgarica
Osmia (Melanosmia) bulgarica Friese, 1923 was treated by Warncke (1988c) and Ungricht et al. (2008) as a subspecies of Osmia inermis (Zetterstedt, 1838) and is currently known from the Mt. Olympus in Greece, the Pepeljak mountain in Northern Macedonia and the Apennine mountains in Italy. The females of O. inermis bulgarica differ from the nominotypical O. inermis by the complete lack of black hairs on the entire body except for the metasomal scopa and by the dense white pilosity on both terga 5 and 6. These differences in the colour of the body pilosity were considered not to be sufficient for treating O. inermis bulgarica as a species of its own. However, the recent examination of a single male of O. inermis bulgarica from the Mt. Olympus in Greece revealed a substantial difference in the width of the emargination at the apical margin of sternum 3, which casts doubts on the conspecifity of the two subspecies and supports the view that O. inermis bulgarica should be elevated to species rank. The females of O. bulgarica from southeastern Europe slightly differ morphologically from those from Italy. Pending the examination of more material and a closer investigation of O. bulgarica and O. inermis populations across all mediterranean mountain ranges, Osmia bulgarica is tentatively regarded here as a species of its own and the population from the Apennines is considered as conspecific with that from the Balkans.