Megachile subnigra Cresson, 1879

Megachile subnigra Cresson, 1879: 208 [♀, ♂].

     Lectotype ♀, designated by Cresson (1916: 131). Nevada, by Morrison [ANSP no. 2423].

Megachile (Xeromegachile) angelica Mitchell, 1934: 318 [♂]. Synonymy by Mitchell (1942: 117) as a variety of Megachile subnigra Cresson, 1879.

     Holotype ♂. USA, California, Los Angeles County, by Coquillett (no. 148) [USNM no. 39971].

Megachile (Xeromegachile) blaisdelli Mitchell, 1934: 336 [♀]. Synonymy of Megachile angelica Mitchell, 1934 by Mitchell (1942: 117).

     Holotype ♀. USA, California, Coronado, 2 June 1890, by F.E. Blaisdell [CAS no. 3617].

Megachile (Xeromegachile) moschata Mitchell, 1934: 338 [♀]. Synonymy of Megachile subnigra angelica Mitchell, 1934 by P.H. Timberlake, in Michener (1951: 1178).

     Holotype ♀. USA, California, Riverside, 3 May 1928, by P.H. Timberlake, on Coreopsis [USNM no. 44249].

Taxonomic notes: Cresson’s (1879: 208-209) original description of this species indicated a ♀ with white pubescence on the metasoma limited to tergum 1, and the lateral apical margin of tergum 2, the ♂ was similar, though with white hair on the margins of terga 2-4; the mid and hind legs black pubescent.

Mitchell’s (1934: 319) description of M. angelica Mitchell, 1934 was similar, though he indicated that terga 2-4 had broad and entire, pale apical fasciae, and with white tarsal fringes, which is consistent with the holotype ♂; he descripted internal structures in a subsequent publication (Mitchell 1937: 372). Similarly, the desription of M. blaisdelli Mitchell, 1934 is consistent with the ♀ of M. subnigra, though with entire pale apical fasciae on terga 2-5 (Mitchell 1934: 337). Mitchell (1942: 117) subsequently recognized M. blaisdelli as the ♀ of his M. angelica and indicated that M. angelica represented a paler colour variety of M. subnigra Cresson rather than a distinct species and indicated that this form differed from M. subnigra by the pale pubescence on the legs, and the more extensive white apical fasciae on the metasomal terga, the latter also a characteristic of the ♀. He subsequently (i.e., Mitchell 1944: 139) referred to M. angelica as a var[iety]. of M. subnigra, though later considered it a valid subspecies (Mitchell 1957: 28).

Megachile (Xeromegachile) moschata Mitchell, 1934 seemingly represents an even paler form of M. angelica, with the scopal hairs pale on stern 1-4, not entirely black as in M. subnigra and M. blaisdelli.

DNA Barcode Index Number (BIN): BOLD:AAD7209

Distribution in Canada: Mitchell 1937 [BC, as M. subnigra Cresson]; Buckell 1950 [BC, as M. subnigra Cresson]; Sheffield et al. 2011 [BC, as M. subnigra Cresson].

Some of the specimens from BC have pale fasciae laterally on terga 3-4, suggesting that intermediate forms exist between specimens with entirely dark scopa (i.e., M. subnigra and M. blaisdelli). As several Megachiloides Mitchell, 1924 are known to have dark forms, without geographical differences in COI, is seems reasonable not to recognize subspecies of M. subnigra, as was done by Sheffield et al. (2011: 58) and Sheffield and Heron (2019: 70).