Megachile (Megachile) inermis Provancher, 1888

Megachile inermis Provancher, 1888: 323 . Drons 2012: 58.

Megachile (Anthemois) inermis; Mitchell 1935b: 171.

Megachile (Megachile) inermis; Mitchell 1962: 126. Hurd 1979: 2055. Ivanochko 1979: 133. Scott et al. 2011: 55. Sheffield et al. 2011: 45. Sheffield and Heron 2019: 70.

Diagnosis. The female of M. inermis can be identified by its distinctively large body size (17–20 mm long), shiny clypeus with sparse punctation medially (punctures 1–3 diameters apart), and clypeal margin with four prominent tubercles. The male of M. inermis can be identified by its large body size (11–16 mm long), unevenly spaced 3- toothed mandibles (2 nd tooth closer to apical tooth), and its nub-like procoxal spine, which is wider than long and covered with a small tuft of dense orange setae. Males are most similar to M. montivaga, which has evenly spaced teeth.

Notes. Megachile inermis, a distinctively large species, has been recorded in several localities in western Montana (Fig. 1O). This species is known to nest in cavities and rotting logs (Sheffield et al. 2011). Photographs, a full morphological description, and notes on its biology can be found in Sheffield et al. (2011).