The Orchard Mason Bee is the common name of a nonsocial native bee (Osmia lignaria ssp.) that pollinates our spring fruit trees, flowers and vegetables. This gentle, blue-black metallic bee does not live in hives. 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. Also, they are active for only a short period of the year. They are not aggressive and one may observe them at very close range without fear of being stung, which makes them excellent for enhancing our yards and gardens. They add beauty, activity and pollination to our plantings. However, they do not produce honey.

About Orchard Mason Bees

The female Orchard Mason Bee visits flowers to collect pollen for its young. She forms a small ball of pollen and nectar in the back of the nesting tube and lays an egg on the ball. She then collects mud to form a cell partition and repeats the pollen ball-egg laying process until she reaches the mouth of the tube where she caps the end with mud. Starting the life cycle in the spring, adult males emerge from tubes first, but must wait for the later appearance of the females in order to mate. This event often coincides with the redbud (Cercis) or Pieris bloom. Females alone, begin founding new nests in holes to make a row of 5-10 cells in each nest. Females collect the pollen and nectar and lay eggs. Their short foraging range is about 100 yards from the nest. Activity continues 4-6 weeks and then adults die. During the summer, larvae develop inside the nests, make cocoons, and become new adults resting in the cells. With the onset of fall, the adults become dormant as they go into hibernation. These bees require some cold temperatures before spring in order to break their dormancy.

This Bee Is Gentle

The orchard mason bee is non-aggressive and will sting only if handled roughly or if it should get trapped under clothing. It is less objectionable than the honey bee as a pollinator in urban areas and should be encouraged. Efforts are being made experimentally to develop large populations of these bees to use as a supplement to honey bees for fruit pollination, much as the alfalfa leafcutting bee was developed for alfalfa seed pollination.