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.