The native orchard mason bee (Osmia lignaria) is smaller than honey bees and lacks the stripes that you may traditionally associate with bees. Sometimes mistaken for houseflies, these bees can be identified by metallic tint – often black, blue, or green. They are generally not aggressive as they live solitary lives with no hive to defend. Male mason bees lack a stinger, and while females can sting they generally do not unless they are squeezed or trapped. One characteristic that makes the mason bees stand out is their early arrival, as they are some of the first bees to emerge in the spring. Mason bees generally emerge from their cocoons when daytime temperatures consistently rise to around 50 degrees.
The early arrival of mason bees is important for local ecosystems and backyards because mason bees are extraordinary pollinators. Mason bees also have a nearly 95% pollination rate, and they don’t shy away from foraging during cool and wet weather, unlike other fair-weather pollinators. In fact, one mason bee can pollinate as many flowers as nearly one hundred honeybees! Female mason bees have pollen-collecting hairs covering their body, unlike honeybees that only carry pollen in receptacles on their hind legs.
The name of the mason bee comes from the craftsmanship they display while building their nests. Female mason bees will seek out small, tube-shaped tunnels that they will use to lay their eggs. First comes collecting pollen and nectar and placing it in the tube, followed by laying an egg, then sectioning off the egg with a wall of mud. The female repeats the pattern – pollen, egg, mud – usually filling the tube with around 10 eggs. Female mason bees will take advantage of naturally occurring holes, such as those drilled by a woodpecker or within a hollow stem, but they can also be supported by providing a bee home.
Because of their gentle nature, mason bees can be extremely enjoyable to observe and support in your own backyard. Portland Audubon’s Nature Store carries a variety of bee houses and accessories, along with an array of books to learn more about mason bees and other pollinators. A few favorite books among staff and volunteers are Mason Bee Revolution and Turn This Book Into a Beehive for kids. You can also learn more about the Backyard Habitat Program to enhance your backyard for a variety of pollinators, birds, and beyond.
Nature Store Deal: When you purchase $15 or more of mason bee products from the Nature Store, you get a box of free mason bee cocoons!
Are you interested in learning more about mason bees?
We have a virtual class coming up on April 6 from 6 – 7 p.m.