Osmia lignaria (info primarily from BC Ministry of Agriculture and Lands Website)

The Orchard Mason bee is the common name of a nonsocial native bee (Osmia lignaria) that pollinates fruit trees, flowers, and vegetables. It is found throughout most of North America, particularly in wooded areas, but often around homes in towns and cities. With the declining feral or wild bee population, the Orchard Mason bee can be easily attracted to pollinate crop plants.

It is a gentle, shiny blue-black metallic bee, and slightly smaller than a honeybee. Males are smaller than females and have longer antennae and an additional tuft of light colored hairs on the face. Females have hairs on the underside of the abdomen adapted for carrying pollen. This bee does not live in a hive. In nature, it nests within hollow stems, woodpecker drillings, and insect holes found in trees or wood. Sometimes, there may be dense collections of individual nest holes, but these bees neither connect or share nests, nor help provision or protect each others' young.

They make excellent pollinating insects, but do not produce honey. A number of species of Orchard Mason Bees are native to North America. They occur in different climatic environments but are particularly well adapted in the northern ranges of blooming fruit trees. The common Blue Orchard Mason Bee, Osmia lignaria, is found in the B.C.’s southern Interior and coastal areas. It goes under various names including Blue Orchard Bee, Orchard Mason Bee, Orchard Bee, and Osmia Bee.

The Orchard Mason Bee belongs to the family Megachilidae which is comprised of a large number of solitary pollinators. The species is gregarious in that they nest close together. This behavior offers several advantages such as lower predation pressures, increased mating opportunity, and optimized genetic variability through cross breeding. It is this gregarious behavior that has offered the opportunity to “domesticate” the Orchard Mason Bee.