Hi Walker et al, Blue Orchard and Orchard Mason are both Osmia lignaria and it is from the family Megachilidae (honeybee - Apidae). The alfalfa leaf cutter bee is also a Megachilid. They are all "buzz pollinators" - that is when they pollinate by vibrating the ventral portion of their body over the flower. The Megachilidae carry their pollen on the underside of their abdomen and this "buzz pollination" has been clearly documented to be more efficient than our honey (- by the - barrel) counterparts. This was the topic of our lecture today in the Beekeeping class, Fruit Science 123 at Cal Poly State University, San Luis Obispo, CA, USA. We are interested in all aspects of pollination and economic entomology. Scott Jeffreys Lecturer and Campus Beekeeper