d she can complete an average of four 6-inch tubes in her lifetime, with about eight eggs per tube. That's nearly 60,000 blossom visits per female. Because of this farmers have cultivated the insect for pollination purposes in fruit orchards.
By the early summer, a larva has consumed all of its provisions and begins spinning a cocoon around itself and enters the pupal stage; the adult females die off as the season progresses.
The young bee is now a fully developed insect and diapauses inside its cocoon for the duration of the winter. They burn through their fat reserves to stay warm. If it stays cold for too long, the bees can die of starvation. Alternatively, if the temperature rises too fast, they may emerge before the blossom. Farmers are known to exploit their emergence cycle and time their release to coincide with the first orchard blossoms.
Commercial Availability. Recently, many people have become interested in the blue orchard bee (Osmia lignaria), also called the orchard mason bee, as a garden and orchard pollinator. Many thousands of mason bee nesting blocks are sold each year in the United States, along with hundreds of thousands of blue orchard bees. This interest has greatly raised public awareness about the importance of pollinators; however, it is important to remember that raising large numbers of a single species (bee-ranching) is a different objective than the conservation of diverse species of wild pollinators.
As mason beekeeping has increased in popularity, important questions are being asked about the risks associated with the nationwide shipment of blue orchard bees by commercial producers. In fact, there are two distinct subspecies of the blue orchard bee: Osmia lignaria propinqua in western North America and Osmia lignaria lignaria in the east. The species is rare in the Great Plains region, although some intermediate specimens have been collected.
Most commercial producers of the blue orchard bee are located in the Pacific Northwest, where they rear the locally native western subspecies 