Megachile (Megachiloides) pascoensis Mitchell, 1934

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 : 38

Megachile (Megachiloides) pascoensis Mitchell, 1934

Megachile (Xeromegachile) pascoensis Mitchell, 1934: 320 .

Megachile (Derotropis) pascoensis ; Mitchell 1944: 142. Hurd 1979: 2062.

Megachile (Megachiloides) pascoensis ; Raw 2002: 16. Kuhlman and Burrows 2017: 13.

Megachile gabrielensis Michell, 1934: 346 ; 1936: 159.

Diagnosis. The female of M. pascoensis can be identified by its 3-toothed mandibles ( Fig. 7A ) and pitted, dull T6 with punctures ≤ 1 diameter apart. The females are most similar to M. anograe (see M. anograe above). The male of M. pascoensis can be identified by its clypeal margin, which has a deep U-shaped median emargination (as deep as wide) ( Fig. 10A ) and the white apical setal band on T5.

Notes. This distinctive species is rare outside of California. In Montana, it is known from a historical record ( Mitchell 1934) and two specimens from Missoula County ( Kuhlman & Burrows 2017) ( Fig. 1 AA). The species was first described in Mitchell (1934) (male = M. pascoensis ; female = M. gabrielensis ) and has not been redescribed or illustrated since. Photographs of the types of both sexes can be found on Big-Bee ( Seltmann et al. 2021).

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.

FIGURE 7. Female Megachile characters. (A–H) Anterolateral view of mandible, (I–N) Lateral view of metasoma, tergites 4–6, (O) Lateral view of tergites on M. dakotensis, and (P) Lateral view of head with pronounced tooth on the posterior genal margin on M. pugnata.

FIGURE 10. Male Megachile characters. (A–C) Anterior view of clypeus: (A) M. pascoensis, (B) M. anograe, (C) M. casadae, (D) Lateral view of tergites on M. dakotensis, (E) Lateral view of tergites on M. onobrychidis, (F) Ventral view of sternites without apicomedial setal patch on S5, (G) Ventral view of sternites of M. anograe with apicomedial setal patch on S5, (H) Lateral view of genal margin with tooth at least as long as wide, and (I) Lateral view of genal margin without obvious tooth.