New synonymies 8
Based on the original descriptions and topotypical specimens, the male of Osmia (Allosmia) decorata described by Morawitz (1886) is conspecific with the female of Osmia (Allosmia) melanura described by Morawitz (1871). Thus, O. decorata is a junior synonym of O. melanura.
Based on the original description, Tkalcu (1974b) and a large Allosmia material from North Africa, Osmia (Allosmia) fossoria Pérez, 1890 is a junior synonym of Osmia (Allosmia) lhotelleriei Pérez, 1887 and not a subspecies of Osmia (Allosmia) sybarita Smith, 1853 as assumed by Tkalcu (1974b). O. sybarita most probably does not occur in North Africa.