Megachile (Megachiloides) nevadensis Cresson, 1879

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 : 37

Megachile (Megachiloides) nevadensis Cresson, 1879

Megachile nevadensis Cresson, 1879: 209 .

Megachile (Xeromegachile) nevadensis ; Mitchell 1937a: 359. Hurd 1979: 2064.

Megachile (Megachiloides) nevadensis ; Raw 2002: 19 . Scott et al. 2011: 56.

Diagnosis. The female of M. nevadensis can be identified by its black scopal setae on S6, white scopal setae on S5, T5 with punctures ≤ 1 diameter apart medially, and 4-toothed mandibles with an asymmetrical emargination between the 3 rd and 4 th teeth that is deepest nearer the 4 th tooth ( Fig. 7C ). The females are most similar to M. manifesta (see M. manifesta above) and M. wheeleri , which has T5 with punctures 2–4 diameters apart medially (see Taxonomic Challenges). The male of M. nevadensis can be identified by its 3-toothed mandibles, its wide and spatulate procoxal spine ( Fig. 8I ), with a short, suberect patch of setae at the base, and carina on mesepisternum with long setae touching the hind coxae. The males are most similar to M. wheeleri and M. manifesta , neither of which have a patch of setae at the base of the procoxal spine.

Notes. This species was recorded from Bozeman, Montana, by Mitchell (1937a), but we were unable to locate the voucher (see Discussion: Searching for Mitchell’s Montana Species). However, collecting in eastern Montana resulted in collection of one male specimen of M. nevadensis in 2021 ( Fig. 1X ). The species was first described in Cresson (1879), then redescribed in more detail in Mitchell (1937a) with illustrations of male characters. Photographs of both sexes can be found on BOLD (http://www.barcodinglife.org).

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 8. Male Megachile characters. (A) Probasitarsus not expanded or excavated ventrally, (B) Probasitarsus widely expanded and excavated ventrally, (C–E) Anterior view of mesobasitarsus and mesotibia, (F) Lateral view of triangular metatarsomeres on M. manifesta, (G) Lateral view of quadrate metatarsomeres on M. wheeleri, (H) Ventral view of procoxal spine, longer than wide, (I) Ventral view of procoxal spine, wide and spatulate, (J–L) Dorsal view of vertex of head: (J) Ocelloccipital distance longer than ocellocular distance, (K) Ocelloccipital distance equal to ocellocular distance, and (L) Ocelloccipital distance shorter than ocellocular distance.