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 ( 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.