Palaearctic Osmia bees of the subgenera Hemiosmia, Tergosmia and Erythrosmia (Megachilidae, Osmiini): biology, taxonomy and key to species Author Müller, Andreas text Zootaxa 2020 2020-05-14 4778 2 201 236 journal article 22161 10.11646/zootaxa.4778.2.1 2bdbfd60-8edf-4efc-9fc3-34649a0e3896 1175-5326 3826170 61BA688B-E383-4A4C-A9F6-D4F53E55645A Subgenus Osmia ( Erythrosmia ) Schmiedeknecht, 1885 Morphological diagnosis Osmia ( Erythrosmia ) species are nonmetallic, robust and small to medium-sized bees ( 5.5–8 mm ) with short-linear parapsidal lines, a medially keeled to weakly spined metanotum, which, however, is often not evident in O. sparsipuncta Alfken and smaller individuals of the other species, a dull basal area of the propodeum and almost lacking to weak whitish tergal hair bands. Except for O . ( Allosmia ) rutila Erichson , O . ( Hoplosmia ) fallax Pérez and O . ( Neosmia ) rufigastra Lepeletier , they are the only Palaearctic representatives of the genus Osmia with a partly or completely red metasoma ( Fig. 24 ). The females are further characterized by a pollen-harvesting comb of apically twistes bristles on clypeus and frons ( Fig. 25, 26 ) and a whitish metasomal scopa.Additional characters of the males are a rather small tergum 7, whose apical margin is truncated, emarginate or weakly four-lobed ( Fig. 30–33 ), and a pair of broad depressions at the base of sternum 6. As in most males of Osmia , tergum 6 is devoid of a lateral tooth, sternum 2 is enlarged, sternum 3 is medially both emarginate and fringed and sternum 6 lacks membraneous basal flaps.