Megachile (Megachile) montivaga Cresson, 1878

Megachile montivaga Cresson, 1878: 124 . Drons 2012: 58.

Megachile (Anthemois) montivaga; Mitchell 1935b: 167.

Megachile (Megachile) montivaga; Mitchell 1962: 127. Butler 1965: 5. Hurd 1979: 2056. Ivanochko 1979: 127. Gonzalez 2008: 35. Scott et al. 2011: 55. Sheffield et al. 2011: 49. Kuhlman and Burrows 2017: 13. Reese et al. 2018: 22. Delphia et al. 2019a: 24. Sheffield and Heron 2019: 70. Engel 2020: 10.

Diagnosis. The female of M. montivaga is distinguished by its light yellow to orange scopal setae on S2–S6, appressed cream-colored setae on T6, its 5-toothed mandibles, which have no cutting edge ventrad the tooth plane, and an elevated ridge running dorsally from the apex of the 2 nd tooth to the point of attachment of the mandible (Fig. 7H). The male of M. montivaga is distinguished by its three evenly spaced mandibular teeth and its nub-like procoxal spine, which is wider than long and covered with a small tuft of dense orange setae. The male of M. montivaga is most similar to M. inermis (see M. inermis above).

Notes. Megachile montivaga has been widely collected in western Montana and from a few eastern localities (Fig. 1W). It is known to nest in soil and old stems. Photographs, a full morphological description, and notes on its biology can be found in Sheffield et al. (2011).