BUG OF THE MONTH: ORCHARD MASON BEE

The Orchard Mason Bee, Blue Orchard Bee, Orchard Bee and Mason Bee are all common names for Osmia lignaria, a native north American pollinating bee that is a wonderfully effective pollinator of early spring blooming plants, shrubs and flowers. The Mason Bee is not a hive-dwelling bee, therefore there is no queen. They are classified as solitary gregarious bees. This means they have no real social interaction with each other but they do like to nest near each other.
The male is easily identified by a small white patch of fuzz on top of its head, while the female is larger and hairier. They are both all black, but do exude a bluish tint when the sunlight hits them just right. They look very similar to a fly, but they have 4 wings extending back along their body.
These hard-working little bees can visit up to 1600 flowers in a day and will effectively pollinate 95% of the plants they visit. Their hairy bodies are very well suited to collecting pollen and as they go from flower to flower the pollen is transferred to the male/female parts of the plants.
The life cycle of the Mason Bee is pretty straight forward. In spring when the day time temperatures start to get in the low to mid fifties with some regularity, the male bees will emerge from their protective cocoons. They spend their time foraging for nectar to build up their strength for mating. While they will do some incidental pollinating while waiting for their potential mates, the majority of the work will be done later by the females.
About two weeks after the males have emerged, the females will make their appearance. After the mating ritual is done, the female then heads out looking for food to get her strength back and find suitable housing for her eggs remaining within about 100 yards of their nests. The males gradually die off.
After finding an appropriate nesting hole, the industrious little female bee will begin to gather pollen and nectar, mixing it together to make a lump of "bee bread" which is placed in the back of the nesting hole. She will then back in and lay her first egg, pushing it into the nectar solution. If she is 4 - 6 inches inside the hole, she knows to create a female egg that will be protected from predators. As she releases the first eggs, she releases sperm from her sperm sack, creating a female egg. She then builds a mud wall to create a small cell. Another lump of food is placed in front of the wall, another egg is released and another wall is built. She works her way down the nesting hole making cell after cell until the entire hole is filled. As she nears the front of the hole, she won't release sperm, thus creating a male egg. How amazing is that!
In a season of gathering and pollinating, a female Mason Bee can lay 32 - 36 eggs. By early summer, her work is done and sadly she will die, but a new generation has been born to hatch next year.
The new little egg hatches after 3 - 4 days revealing the larva. The larva consumes the food that was left over a period of 28 days or so. After a period of rest, it will begin the process of spinning a cocoon which will take a day or two. When that is complete, it will rest again for a time until it turns into a pupa. It will complete its final stage of development by mid September. In its warm, water proof shelter, the little bee will hibernate and wait until late winter, early spring the next year to emerge and the cycle is complete.
You can purchase nesting tubes and houses for Mason Bees. If you do, place it in a sunny location that is sheltered from wind and rain. Provide a nice mud puddle close to the nests. In late June, bring the bees inside to a cool area like a shed or garage to protect them from Flickers and predatory insects. The next January/mid-February, transfer the bees to a refrigerator to prevent early hatching. Finally, put all bees and housing out in the sun again.