The blue orchard bee (Osmia lignaria), Japanese hornfaced bee, Osmia cornuta and the Spanish hornfaced bee (Osmia cornifrons), are examples of Mason bees. They are solitary bees that use mud to seal the ends of their nesting tunnels. Osmia bees do not live in complex social colonies or hives like honey bees do. They are very social bees that prefer to nest in close proximity to each other. Because there is no shared labor among these bees, all females construct their own nests independently. Unlike honey bees, mason bees do not produce honey, wax, or any other products of interest to humans. But in light of the recent decline of honey bee populations, their pollination service is greatly valued!
Mason bees are about 2/3 the size of a honey bee, that is approximately 1/2 of an inch. A native of North American, blue orchard bees are found throughout most of the United States except for the deep south and they are not plentiful in the great plains. The blue orchard bee is black with a shiny blue metallic patch on its back and has, just as the honey bee does, a double wing on each side of its body. It's easy to mistake this little blue bee for a house fly and many have been mistakenly killed. You can distinguish a Blue Orchard Bee from a house fly by its wings; the bee has a pair of wings on both side where a house fly has only one wing, and the male Blue Orchard Bee also had a white, whiskery moustache.
The Japanese hornfaced bee, a small insect imported from Japan, is helping to increase fruit yields in United States orchards by pollinating apple, peach, cherry, and plum blossoms more efficiently than the honeybee which is the common pollinator of American orchards and gardens.
As soon as the first blossoms of spring appear (sometimes later) and the weather begins to get warmer, you should see activity at your Solitary Bee House. They are simply tireless workers, making hundreds of flights per day, stashing pollen into the nesting holes. Observing Blue Orchard Bees could become a great pastime, especially for children, offering them unusual materials for conversations at school.
Social bees like honey bees will readily sting people or animals that threaten the welfare of their colony. The protection of the queen, young bees, and honey reserves are of utmost importance, and worker bees will give their lives to protect the integrity of the hive. In contrast, non-agressive mason bees have little to defend and will only sting in self-defense if, for example, they get caught under clothing. Their sting can be compared to a mosquito bite but people allergic to insect bites should still exercise great caution.
