Mason bees: Osmia cascadica
(Hymenoptera: [Apoidea:] Megachilidae: Megachilinae: Osmiini)
Profile prepared by Matthew Shepherd, The Xerces Society for Invertebrate Conservation
Osmia cascadica appears to be a specialist forager on flowers in the family Scrophulariaceae. It is assumed that like it nests in abandoned beetle burrows in wood and stems. Osmia cascadica is endemic to the high Cascades bounding the Columbia Basin and while it is apparently fairly common in the areas that it occurs, due to this restricted geographic distribution it should be considered vulnerable.
Xerces Red List Status: Vulnerable
Other Rankings:
Canada – Species at Risk Act: N/A
Canada – provincial status: N/A
Mexico: N/A
USA – Endangered Species Act: N/A
USA – state status: N/A
NatureServe: N/A
IUCN Red List: N/A
Because Osmia cascadica is apparently fairly common in the areas that it occurs, it is likely relatively secure. However, it is endemic to the high Cascades bounding the Columbia Basin and due to this restricted geographic distribution it should be considered vulnerable.
The flight season of Osmia cascadica is in July and August. Osmia cascadica appears to be a specialist forager on flowers in the family Scrophulariaceae. It is assumed that like most other members of the subgenus Chenosmia, Osmia cascadica nests in abandoned beetle burrows in wood and stems.
It has been recorded within the Columbia Basin in Engelmann spruce – subalpine fir, Mountain big sagebrush, and Interior ponderosa pine habitat.
Although endemic to the Columbia Basin, Osmia cascadica is fairly common but apparently restricted to the high Cascades.
Due to the limited information available on this species specific threats cannot be identified.
Ensure that suitable flowering plants persist and that appropriate nesting substrate remains. Little is known of the biology of this species. Studies of the phenology, nesting requirements, and foraging habits would be valuable. Further surveys of the high Cascades should be undertaken to confirm the distribution of this species.
Tepedino, V.J., and T.L. Griswold. 1995. The bees of the Columbia Basin. Final report, USDA Forest Service, Portland, OR. 212 pp (Technical Report)
Shepherd, M. D. 2005. Species Profile: Osmia cascadica. In Shepherd, M. D., D. M. Vaughan, and S. H. Black (Eds). Red List of Pollinator Insects of North America. CD-ROM Version 1 (May 2005). Portland, OR: The Xerces Society for Invertebrate Conservation.