Atoposmia

Distinguished from other Osmiini genera by the combination of a strongly hooked apical margin of the clypeus, reduced or absent arolia between the tarsal claws, and specific modifications to the male genitalia. Females lack the strong scopal hairs on the ventral metasoma seen in some related genera. Male Atoposmia have distinctive sternal modifications not present in females.

Associated with rocky or cliff environments where suitable nesting cavities occur in crevices or hollow stems. Found in montane and subalpine regions of western North America.

Western North America, primarily in mountainous regions from Alaska and Canada south through the Rocky Mountains to California and New Mexico. Disjunct populations occur in eastern Asia.

Solitary nesting behavior using pre-existing cavities. Females partition nest cavities into brood cells using partitions constructed from collected materials. No evidence of social behavior or parasitism in this genus.

Pollinator; females collect pollen and nectar to provision brood cells, facilitating plant reproduction in montane ecosystems.

Potential pollinator of montane and subalpine flora; no documented economic importance or management concerns.

• OsmiaBoth are Osmiini with similar overall body form, but Osmia lacks the hooked clypeal margin and has well-developed arolia.
• AshmeadiellaSimilar size and habitat preferences, but Ashmeadiella has a straight or weakly curved clypeal margin and different male genitalic structure.
• HoplitisOverlaps in distribution and nesting biology; Hoplitis lacks the diagnostic clypeal hook and typically has different sternal morphology in males.

• bee
• solitary bee
• megachilidae
• osmiini
• montane
• rocky habitat
• cavity nester
• pollinator
• western north america

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life