Nomada alpha Cockerell, 1905

Nomada alpha Cockerell, 1905: 84 [♀].

     Holotype ♀. USA, Colorado, Fort Collins, 20 May 1903, by F. C. Bischopp, on Capsella bursa-pastoris [].

Nomada alpha var. paralpha Cockerell, 1921: 3 [♀].

     Holotype ♀. USA, Colorado, Walden, about 8400 ft., among sagebrush on hillside, 17 June 1920 [].

Nomada alpha var. dialpha Cockerell, 1921: 3 [♀].

     Syntypes ♀. USA, Colorado, Walden, about 8300 ft., on the more mesophytic river-bottom among willows, cottonwood, Iris, etc., 17 June 1920 [].

Taxonomic Notes: The ♂ was described by Swenk (1913: 74, incorrectly referred to as an allotype) based on co-occurence.

Swenk (1913: 72) commented on the amount of variation within Nomada alpha Cockerell (subgenus Heminomada Cockerell and Atkins = ruficornis group of Alexander 1994: 222), describing an additional specimen that was conspecific, but not as extensively red (i.e., erythrizatized) as the holotype, and noted its similarity to the slightly larger (i.e., 10-11 mm) N. morrisoni Cresson and N. flagellaris Cockerell, the latter placed as a subspecies of N. morrisoni in Rodeck (1951: 1202) and Hurd (1979: 2110), and also N. crawfordi Cockerell, N. elrodi Cockerell, N. obliterata Cresson (the latter three also members of the Heminomada group as per Rodeck (1951: 1197) and Hurd (1979: 2105), who treated as a subgenus. Interestingly Rodeck (1951: 1201) and Hurd (1979) placed N. morrison within subgenus Pachynomada Rodeck (= vincta group of Alexander 1994: 215), but it was not included in Broemeling and Moalif’s (1988) revision of the subgenus, and it was subsequently placed in the ruficornis group by Alexander and Schwarz (1994: 250). Subsequently, Cockerell (1921: 2) indicated that N. alpha Cockerell was indeed a variable species and considered that it and N. morrisoni were likely conspecific, despite differences in size, though the synonymy was not supported elsewhere (e.g., Hurd 1979). The two new varieties he described varied from the typical form mainly in being slightly larger (about the same size as N. morrisoni), with slight differences in colour patterning. These have been considered valid subspecies by Rodeck (1951: 1197), Hurd (1979: 2105), and Alexander and Schwarz (1994: 244). Due to the amount of variation within this species within the type locality, subspecific taxa are not recognized here.

Distribution in Canada: Fredenburg 2020 [ON]; Fredenburg et al. 2021 [ON]; Gibbs et al. 2023 [MB].