Megachile (Megachiloides) dakotensis Mitchell, 1926

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 : 31

Megachile (Megachiloides) dakotensis Mitchell, 1926

Megachile dakotensis Mitchell, 1926b: 164 .

Megachile (Xeromegachile) dakotensis ; Mitchell 1937a: 335; 1944: 136; 1962: 145. Hurd 1979: 2063.

Megachile (Megachiloides) dakotensis ; Raw 2002: 17 .

Diagnosis. The female of M. dakotensis can be identified by the shape of T3–5, which are strongly concave between the depressed apical and basal grooves ( Fig. 7O ), reddish tibiae apically, and the asymmetrical emargination between its 3 rd and 4 th (basal) teeth with emargination deepest closer to the 4 th tooth ( Fig. 7C ). The male of M. dakotensis can be identified by its procoxal spine ( Fig. 8H ), which is longer than wide, reddish tibiae apically (front tibiae can be yellowish apically), and the shape of T2–4, which are strongly concave between the depressed apical and basal grooves ( Fig. 10D ).

Notes. Mitchell (1937a) recorded this species from Montana without a more specific locality, and since then, only two specimens have been collected in Montana, both at Medicine Rocks State Park, near the eastern border, in 2020 ( Fig. 1I ). We have been unable to locate Michell’s voucher. This rarely collected species was first described in Mitchell 1926b, then redescribed in Mitchell (1937a) and Mitchell (1962) with male characters illustrated. 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.

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.