Osmia (Tergosmia) Warncke, 1988

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 : 217

Subgenus Osmia (Tergosmia) Warncke, 1988

Morphological diagnosis

Osmia (Tergosmia) species are nonmetallic, robust and small to medium-sized bees (5.5–10 mm) with punctiform to short-linear parapsidal lines, a predominantly dull basal area of the propodeum and whitish to yellowish tergal hair bands, which are continuous or interrupted. Except for O. lunata Benoist , the females are characterized by the lack of orange hairs or hair brushes along the apical margin of the clypeus, which are typical for most other Palaearctic representatives of the genus Osmia . The metasomal scopa is either whitish or blackish. Diagnostic characters of the males are the similar form and size of sterna 2 and 3 lacking fringed emarginations and the strong median emargi- nation of sternum 5, which is beset with hairs except for O. lunata . Male tergum 7 strongly varies in shape among species and is either prolonged into a long spine, narrowly rectangular with two lateral and widely spaced long teeth, bilobed or bispinose ( Fig. 20–23 ). As in most males of Osmia , tergum 6 lacks a lateral tooth except for O. avosetta Warncke and sternum 6 is devoid of membraneous basal flaps.

Figures

FIGURES 15–23: Osmia (Tergosmia). 15: Female of O. tergestensis in front of her brood cell hidden in a rock fissure (photo A. Krebs). 16: Female of O. tergestensis folding petal after having it bitten off from flower of Geranium pyrenaicum (Geraniaceae; photo A. Krebs). 17: Brood cells of O. tergestensis between blades of dense grass tussock. 18: Brood cell of O. avosetta at the end of a short burrow in the ground (photo C. Sedivy). 19: Female of O. lunata depositing nectar in her brood cell built in a short burrow in the ground. 20–22: Male terga 6–7 of O. avosetta (20), O. lunata (21), O. rhodoensis (22) and O. tergestensis (23).