Blue Orchard Bee

Photo by: Bryan Reynolds


What else is the Blue Orchard Bee called?


The Blue Orchard Bee is also called BOB, for short, or Mason Bee.

Osmia lignaria

The Blue Orchard Bee, Osmia lignaria, is a distinctive species. Opposed to the typical black-and-yellow coloring of a steriotypical bee, these bees are blue-black in appearance. Manyshow a shimmering blue. Because of their metallic appearance, Blue Orchard Bees can be mistakenly identified as sweat bees (the Halictidae family).

Blue Orchard Bees are unique in other ways besides appearance. While the eggs and larvae are almost indistinguishable from those of Honey Bees, Blue Orchard Bees nest individually, unlike the Honey Bees’ preference for colonial hives. Female bees do most of the work in this regard. Each finds a mate and proceeds to make a nest. They prefer to make nests in pre-existing structures. Blue Orchard Bees can’t bore through wood, like carpenter bees, or use leaves to build structures, unlike Leaf Cutter Bees. Osmia Lignaria’s medium of choice is mud. Inside the nest, the female creates partitions and cubbies for each egg, laying upto 5. Pollen and nectar are also included with the eggs. Even though they prefer to be solitary, Blue Orchard Bees usually don’t attack each other, or humans, for that matter. Males are smaller than females, measuring roughly 1 centimeter in length, compared to the average 1.5 centimeter females. Males can be distinguished by their longer antennae.

Blue Orchard Bees are widely distributed across the continental United States, which arebroken up into two subspecies divided by the Rocky Mountains. The bee’s presence is highly desirable for farmers — Blue Orchard Bees are so named because they excel at pollinating orchard trees, such as almond, apple, pear, and cherry. The Blue Orchard Bee carries pollen onits back abdomen, instead of its legs, spreading more pollen than Honey Bees. To encourage their presence, farmers construct “bee houses” (like bird houses), with pre-constructed individual tunnels (make your own bee house!

Written by: Robert Gibson, an undergraduate Environmental Studies student at the University of Oklahoma