Osmia (Erythrosmia) Schmiedeknecht, 1885

Müller, Andreas, 2020, Palaearctic Osmia bees of the subgenera Hemiosmia, Tergosmia and Erythrosmia (Megachilidae, Osmiini): biology, taxonomy and key to species, Zootaxa 4778 (2), pp. 201-236 : 225

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.

Figures

FIGURES 24–33: Osmia (Erythrosmia). 24: Female of O. andrenoides on Stachys recta (Lamiaceae; photo A. Krebs). 25: Face of female of O. andrenoides with specialized pollen-collecting bristles on clypeus and frons. 26: Pollen-collecting bristles on female clypeus of O. andrenoides in side view. 27: Nesting site of O. andrenoides in cavity under rock prominence. 28: Nest of O. andrenoides in shell of Zebrina detrita sealed with wall of leaf pulp. 29: X-rayed nest of O. andrenoides with entrance barrier of densely packed small particles. 30–33: Male terga 6–7 of O. andrenoides (30), O. erythrogastra (31), O. relicta (32) and O. sparsipuncta (33).