MASON BEES

OsMiA Spp.

Like sweat bees, most mason bees have a metallic green or blue coloration, although some may have a rusty-reddish color. Mason bees are solitary and construct their nests in cracks, holes made by wood-boring creatures, or other naturally occurring tubular cavities such as hollow twigs or plant stems. When building a nest the female will fill the tube with a series of cells each containing an egg along with pollen and nectar for the developing larva to feed on. Each cell is separated by a wall of mud. Mason bees are excellent pollinators, although unlike many bees which collect pollen on their hind legs, mason bees collect pollen using hairs on their abdomen.

You can encourage mason bees in your garden by leaving dead stems standing to provide a tube for their nest cavity.