Megachile (Megachiloides) wheeleri Mitchell, 1927

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 : 41

Megachile (Megachiloides) wheeleri Mitchell, 1927

Megachile wheeleri Mitchell, 1927: 107 .

Megachile (Xeromegachile) wheeleri Mitchell. Butler 1965: 9 . Hurd 1979: 2066. Ivanochko 1979: 244. Mitchell 1937a: 355.

Megachile (Megachiloides) wheeleri Mitchell. Raw 2002: 21 . Scott et al. 2011: 56. Sheffield et al. 2011: 61. Reese et al. 2018: 22 . Sheffield and Heron 2019: 70.

Megachile spokanensis Mitchell, 1927: 109 .

Diagnosis. The female of M. wheeleri can be identified by its 4-toothed mandibles with an asymmetrical emargination between the 3 rd and 4 th tooth, emargination deepest closer to 4 th tooth, and the widely spaced punctures on the apical half of T5, which are separated by 3–4 diameters. Females of M. wheeleri are most similar to M. manifesta (see M. manifesta above) and M. nevadensis (see M. nevadensis above and Taxonomic Challenges). The male of M. wheeleri can be identified by its wide and spatulate procoxal spine without a setal patch at the base, the protruding triangular carina on the ventral mesepisternum (viewed ventrally, directly posterior to the procoxal spine), and the quadrate metatarsomeres (viewed laterally) ( Fig. 8G ).

Notes. This species occurs in central Montana and the lower elevations of western Montana, west of 109° ( Fig. 1 AI). This is the only member of Megachiloides besides the rarely seen M. pascoensis that has been found west of the divide. Photographs, a full morphological description, and notes on the biology of this soil-nesting species 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.

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.