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Osmia montana montana Cresson, 1864


Scientific Name: Osmia montana montana Cresson, 1864

Common Name: Montana Mason Bee


Osmia montana Cresson, 1864: 24 [♂].

     Lectotype ♂, designated by Cresson (1916: 124). USA, Colorado [Territory], Pike’s Peak [ANSP no. 2529]

Osmia armaticeps Cresson, 1878: 104 [♀]. Synonymy by Sandhouse (1939: 23).

     Lectotype ♀, designated by Cresson (1916: 112). USA, Colorado, by J. Ridings, H.K. Morrison [ANSP no. 2531].

Osmia armaticeps var. saponellis Cockerell, 1901: 336 [♀]. Synonymy by Sandhouse (1939: 23).

     Holotype ♀. USA, New Mexico, hill above Beulah, 19 August [no year provided], by T.D.A. Cockerell [USNM no 23335].


Taxonomic Notes: A second subspecies, O. montana quadriceps Cresson, 1878, reaches as far north as southern Washington (Rust 1974). Cresson (1878: 104), Sandhouse (1939: 22) and Rust (1974: 61) separated females of the two subspecies based mainly on hair colour, O. montana quadriceps being entirely black pubescent, and the shape and extent of the hypostomal carina, the nominate taxon with a prominent tooth. Sandhouse (1939: 23) also distinguished the males (treating them as two species) mainly based on the shape of sternum 6, though Rust (1974: 61) did not, at least in the key, though indiated in the diagnosis that sternum 4 had the median lobe sparsely covered with hairs in O. montana quadriceps, but densely pubescent in the nominate species.

DNA Barcode Index Number (BIN): BOLD:AAE5493

Both subspecies share this BIN.

Biology: This species nests in pre-existing cavities in wood with diameters of 6.4 mm to 9 mm, and hollow stems (Rust 1974; Tepedino et al. 2022). Its pollen preferences seem to be confined to composites. Rust (1974) gave a detailed description of the nesting biology and floral preferences, and indicated that Stelis montana Cresson was a nest parasite (Rust 1974; Torchio 1989b). Tepidino et al. (2022) indicated that this species is parsivoltine, with populations containing individuals that will winter for one or two years.

Distribution in Canada: Gibson 1916 [BC, as O. armaticeps Cresson]; Sandhouse 1939 [BC]; Buckell 1950 [BC]; Rust 1974 [BC, based on dots on map]; Elwell 2012 [BC]; Sheffield and Heron 2019 [BC].

Body length: ♀ 14-15 mm ♂ 11 mm


Cresson ET (1878) Descriptions of new North American Hymenoptera in the collection of the American Entomological Society. Transactions of the American Entomological Society 7: 61-136.

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

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

Sandhouse GA (1939) The North American bees of the genus Osmia (Hymenoptera: Apoidea). Memoirs of the Entomological Society of Washington 1: 1-167.

Rust RW (1974) The systematics and biology of the genus Osmia, subgenera Osmia, Chalcosmia, and Cephalosmia (Hymenoptera: Megachilidae). The Wasmann Journal of Biology 32(1): 1-93.

Cresson ET (1864) On the North American species of the genus Osmia. Proceedings of the Entomological Society of Philadelphia 3: 17-38.

Cockerell TDA (1901) Contributions from the New Mexico Biological Station. —XI. New and little-known insects from New Mexico. Annals and Magazine of Natural History, Series 7 7(40): 333-337.

Tepedino VJ, Parker FD, Durham SL (2022) Mixed diapause duration in cohorts of four species of Osmia bees (Megachilidae) along an elevation and temperature gradient in Northern Utah (USA). Journal of Apicultural Research 61(4): 481-491.

Torchio PF (1989b) Biology, immature development, and adaptive behavior of Stelis montana, a cleptoparasite of Osmia (Hymenoptera: Megachilidae). Annals of the Entomological Society of America 82(5): 616-632.

Wong LH, Forrest JRK (2021) The earlier the better? Nesting timing and reproductive success in subalpine cavity-nesting bees. Journal of Animal Ecology 90(5): 1353-1366.

Sociality: Solitary
Nesting: Cavity Renter
Pollen Specialization: Broad Oligolecty
Wintering Stage: Adult

Crop Preference: Not Available
Non Crop Preference: Aster sp., Gutierrezia sp., Taraxacum sp., Potentilla sp., Senecio sp., Balsamorhiza sp.

Distribution: British Columbia
Ecozone: Montane Cordillera, Pacific Maritime, Western Interior Basin

Distribution Map