''Osmia californica'' is a

megachilid Megachilidae is a cosmopolitan family of mostly solitary bees. Both that their pollen-carrying structure (called a ''scopa'') is restricted to the ventral surface of the abdomen (rather than mostly or exclusively on the hind legs as in other be ...

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyly, monophyletic lineage within the ...

, or mason bee. Native to North America, the mason bees are important pollinators. ''O. californica'' generally emerges a little later in the spring than the better known orchard mason bee ('' O. lignaria''). Like the orchard mason bee, ''O. californica'' is a solitary nester.

References

californica Hymenoptera of North America Insects of the United States Insects described in 1864 Taxa named by Ezra Townsend Cresson {{Megachilidae-stub