New synonymies
R. Le Divelec discovered in the Muséum National d’Histoire Naturelle de Paris the male holotype of Protosmia (Protosmia) monstrosa (Pérez, 1895), which was assumed to be lost. The male clearly belongs to P. (Protosmia) tiflensis (Morawitz, 1875). Thus, P. monstrosa is a junior synonym of P. tiflensis and not identical with P. (Protosmia) mirabilis (Friese, 1899) as assumed by Alfken (1935b).
After examination of the types, the two following synonymies suspected by Branstetter et al. (2021) are confirmed: i) Osmia (Osmia) yanbianense Wu, 2004 is a junior synonym of O. (Osmia) opima Romankova, 1985 and ii) Osmia (Osmia) rufinoides Wu, 2004 is a junior synonym of O. (Osmia) rufina Cockerell, 1931.