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Home » Guide » Arthropods (Arthropoda) » Hexapods (Hexapoda) » Insects (Insecta) » Ants, Bees, Wasps and Sawflies (Hymenoptera) » Aculeata - Ants, Bees and Stinging Wasps » Apoidea (clade Anthophila) - Bees » Leafcutter, Mason, and Resin Bees, and allies (Megachilidae) » Leafcutter, Resin, Mortar, Sharptail, Mason, and Woolcarder bees and relatives (Megachilinae) » Mason bees and relatives (Osmiini) » Mason Bees (Osmia)

Genus Osmia - Mason Bees

Classification · Explanation of Names · Numbers · Identification · Range · Season · Food · Remarks · Print References · Internet References · Works Cited

Osmiini 01b - Osmia coloradensis - female

Bee house, the next generation - Osmia cornifrons - male

Metallic green bee - Osmia ribifloris - male

Classification

Kingdom Animalia (Animals)

Phylum Arthropoda (Arthropods)

Subphylum Hexapoda (Hexapods)

Class Insecta (Insects)

Order Hymenoptera (Ants, Bees, Wasps and Sawflies)

No Taxon (Aculeata - Ants, Bees and Stinging Wasps)

No Taxon (Apoidea (clade Anthophila) - Bees)

Family Megachilidae (Leafcutter, Mason, and Resin Bees, and allies)

Subfamily Megachilinae (Leafcutter, Resin, Mortar, Sharptail, Mason, and Woolcarder bees and relatives)

Tribe Osmiini (Mason bees and relatives)

Genus Osmia (Mason Bees)

Explanation of Names

Osmia Panzer 1806

Numbers

~150 spp. in 9 subgenera our area, >350 spp. in 23 subgenera total(1)

Identification

Metallic green to blue (sometimes all black), with robust body and no pygidial plate(2)

Parapsidal lines are actually small pits rather than lines: arrows

Unique to Osmia is the arolium between the front claws(2):

Range

Holarctic, with 1 sp. ranging into the Neotropics [map](1)

Season

Most species early-late spring, a few active in summer.

(starts flying in Jan. in sw US, in Mar. elsewhere)

Food

Many species visit Vaccinium, including blueberries, and other Ericaceae.

Remarks

Variety of nesting; some excavate in the soil, others use hollow stems, some use abandoned mud wasp nests. They partition the cells with walls made of clay or other materials.

Print References

Cane J.H., Griswold T., Parker F.D. (2007) Substrates and materials used for nesting by North American Osmia bees (Hymenoptera: Apiformes: Megachilidae). Ann. Ent. Soc. Am. 100: 350–358. (Full text)

Michener C.D. (1949) A revision of the American species of Diceratosmia (Hymenoptera, Megachilidae). Ann. Ent. Soc. Am. 42: 258-264. (Full text)

Rust R.W. (1974) The systematics and biology of the genus Osmia, subgenera Osmia, Chalcosmia and Cephalosmia (Hymenoptera: Megachilidae). Wasmann J. Biol. 32: 1-93. (3)

Sandhouse G.A. (1924) Bees of the genus Osmia in the collection of the California Academy of Sciences. Proc. Calif. Acad. Sci. (4) 13: 341-372. (Full text)

Sandhouse G.A. (1939) The North American bees of the genus Osmia. Mem. Ent. Soc. Wash. 1: 1-167. (4)

Sinha R.N. (1958) A subgeneric revision of the genus Osmia in the Western Hemisphere (Hymenoptera: Megachilidae). Kans. Univ. Sci. Bul. 39: 211-261. (Full text)

Sinha R.N., Michener C.D. (1958) A revision of the genus Osmia, subgenus Cetrosmia (Hymenoptera: Megachilidae). Kans. Univ. Sci. Bul. 39: 275-303. (5)

Snelling R.R. (1967) Description of a new subgenus of Osmia (Hymenoptera: Megachilidae). Bull. S.Cal. Acad. Sci. 66: 103-108 (Full text)

White J.R. (1952) A revision of the genus Osmia, subgenus Acanthosmioides (Hymenoptera: Megachilidae). Kans. Univ. Sci. Bul. 35: 219-307. (Full text)

Internet References

BOLD

Hi-res images of ~70 spp.

Taxon page(1)

Phoretic mites on Osmia

Works Cited

1.	Ascher J.S., Pickering J. (2024) Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila)

2.	The Bees in Your Backyard: A Guide to North America's Bees. Joseph S. Wilson & Olivia J. Messinger Carril. 2015. Princeton University Press.

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

4.	The North American bees of the genus Osmia G.A. Sandhouse. 1939. Mem. Ent. Soc. Wash. 1: 1-167.

5.	A subgeneric revision of the genus Osmia in the Western Hemisphere (Hymenoptera: Megachilidae) R. N. Sinha . 1958. Kans. Univ. Sci. Bul. Vol. 39, No. 5, pp. 211-261.

Contributed by Richard Leung on 15 April, 2005 - 8:36pm
Additional contributions by Beatriz Moisset, Chuck Entz, Mike Quinn, John S. Ascher, Aaron Schusteff, kschnei, v belov, Edward Ruden, Marci Hess, dvoribird
Last updated 12 June, 2023 - 8:26am

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