Megachile (Megachiloides) casadae Cockerell, 1898

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 : 30

Megachile (Megachiloides) casadae Cockerell, 1898

Megachile casadae Cockerell, 1898: 127 . Drons 2012: 58.

Megachile (Xeromegachile) casadae Cockerell ; Mitchell 1934: 302; 1937a: 348; 1944: 136. Butler 1965: 7. Hurd 1979: 2063. Megachile (Megachiloides) casadae Cockerell ; Raw 2002: 17 . Scott et al. 2011: 55. Sheffield et al. 2011: 54.

Megachile austinensis Mitchell, 1927a: 105 .

Diagnosis. The female of M. casadae can be identified by a shiny and sparsely punctate clypeus medially, 4-toothed mandibles with an asymmetrical emargination between the 3 rd and 4 th teeth that is deepest closer to the 4 th tooth ( Fig. 7C ), black scopal setae on S6, and T6 with an elevated ridge apicomedially (appears laterally “pinched” in dorsal profile), with dense brown setae along ridge directed medially. The male of M. casadae can be identified by 3-toothed mandibles, wide and spatulate procoxal spines ( Fig. 8I ), and a slight medial emargination in its otherwise mostly straight clypeal margin ( Fig. 10C ).

Notes. This species is a new state record for Montana. Megachile casadae is most common to the south of Montana ( Fig. 1F ) and reaches its northernmost extent in Montana, east of the divide, and southern Alberta. Photographs, a full morphological description, and notes on the biology of this 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 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.