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Megachile subnigra Cresson, 1879


Scientific Name: Megachile subnigra Cresson, 1879

Common Name: Black-bottomed Leafcutter Bee


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).


Cresson ET (1879) Descriptions of new North American Hymenoptera in the collection of the American Entomological Society. Transactions of the American Entomological Society 7: 201-214.

Mitchell TB (1934) A revision of the genus Megachile in the Nearctic region. Part I. Classification and descriptions of new species (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 59(4): 295-361.

Mitchell TB (1936) A revision of the genus Megachile in the Nearctic region. Part V. Taxonomy of the subgenus Xeromegachile (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 62(4): 323-382.

Sheffield CS, Heron JM (2019) The bees of British Columbia (Hymenoptera: Apoidea, Apiformes). Journal of the Entomological Society of British Columbia 115: 44-85.

Cresson ET (1916) The Cresson types of Hymenoptera. Memoirs of the American Entomological Society 1: 1-141.

Michener CD (1951) Family Megachilidae. In: Muesebeck CF, Krombein KV, Townes HK (Eds) Hymenoptera of America north of Mexico Synoptic Catalog. 2. United States Department of Agriculture Agricultural Monograph, Washington. Pp. 1136-1186.

Buckell ER (1950) Record of bees from British Columbia: Megachilidae. Proceedings of the Entomological Society of British Columbia 46: 21-31.

Mitchell TB (1944) New species and records in Megachile (Hymenoptera, Megachilidae). Pan-Pacific Entomologist 20(4): 132-143.

Sheffield CS, Ratti C, Packer L, Griswold T (2011) Leafcutter and mason bees of the genus Megachile Latreille (Hymenoptera: Megachilidae) in Canada and Alaska. Canadian Journal of Arthropod Identification 18: 1-107.

Mitchell TB (1942) Notes and descriptions of Nearctic Megachile (Hymenoptera, Megachilidae). The Pan-Pacific Entomologist 18(3): 115-118.

Mitchell TB (1957) New species and records of Xeromegachile and Derotrpis (Hymenoptera, Megachilidae). The Pan-Pacific Entomologist 33(1): 19-29.

Sociality: Solitary
Nesting: Ground
Pollen Specialization: Polylectic
Wintering Stage: Mature Larva

Crop Preference: Not Available
Non Crop Preference: Not Available

Distribution: British Columbia
Ecozone: Western Interior Basin

female; lateral view
female; lateral view
male; lateral view
male; lateral view

Distribution Map