Megachile (Megachile) inermis Provancher, 1888

Pritchard, Zoe A., Ivie, Michael A., O’Neill, Kevin M. & Delphia, Casey M., 2025, A faunal treatment of the Megachile (Hymenoptera: Megachilidae) of Montana with a key for their identification, Zootaxa 5683 (1), pp. 1-51 : 33-34

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).

Figures

FIGURE 1. County-level distribution of each Megachile species in Montana. Females identified as Megachile latimanus/ Megachile perihirta (and data without recorded specimen sexes) are counted here as M. perihirta as they are not distinguishable from one another in Montana. Males identified as Megachile lapponica/Megachile relativa (and data without recorded specimen sexes) are counted here as M. relativa as they are not distinguishable from one another in Montana. Mitchell county records are included on maps but not in specimen counts. Two specimens did not have county-level localities and are not included in maps but are included in specimen counts.