Beneficial Because:
Mason bees are driven to collect huge amounts of pollen, which they make into balls and store for their young. On a warm spring day when fruit trees are in bloom, a single mason bee may make over 1,000 visits to collect pollen, all the while spreading bits of pollen from flower to flower. Because of their small size, mason bees are able to crawl inside tubular blueberry blossoms where honeybees do not fit.
Food and Habitat:
Mason bees earned their common name because they pack the cells of their nests with mud, but not before each compartment is stocked with an egg and a pollen ball for the hatchling to eat. Insect holes in trees are common nest sites, along with hollow sticks or branches. Some mason bees may nest in the ground. Mason bees are solitary insects that do not form colonies.
Attracting More:
Locations near wooded areas often host plenty of mason bees, but in urban areas with limited natural habitat you can make mason bee boxes by drilling holes into blocks of wood, or by providing bundles of hollow bamboo or even drinking straws, attached to fences, tree limbs or buildings. Homemade "insect hotels" are designed primarily to host mason bees.