Gentle, Native Super Pollinators!
The Mason Bee or Blue Orchard Bee (Osmia Lignaria) is a solitary native bee that does a superb job of pollinating early blooming fruit trees and flowers. It is found throughout most of North America, and was here before the common honey bees were brought over from Europe in 1622. With the recent severe impact of CCD on honey bee populations, the need for alternative and supplemental pollinators is critical to our overall ecology, and vitally important to agricultural production.
The charming Mason Bee is a gentle, shiny blue-black metallic bee, and slightly smaller than a honey bee. They are a superior pollinator, but do not produce honey. Only 350 females are needed to pollinate an acre of apple trees rather than 25,000 honey bees. After emerging in the spring from cocoons, these solitary bees first mate, and then the female begins to forage pollen and nectar from flowers for next year’s offspring.
The Mason Bee gets its common name from their nesting habit of using mud to create protective partitions for their young when reproducing. When the female has provided a sufficient supply of food for the larva, she lays an egg and then seals the cell with a thin mud plug. She then provisions another cell, and continues in this fashion until the hole is nearly full. Finally, the mason bee plasters a thick mud plug at the entrance.
They are not aggressive and they may be observed at very close range without fear of being stung, unless they are handled roughly or if trapped under clothing. In nature, the Mason Bee nests within hollow stems, woodpecker drillings, and insect holes found in trees or wood. Sometimes, there may be dense collections of individual nest holes, but these bees neither connect or share nests, nor help provision or protect each others' young. Although they can pollinate up to 80x better than honey bees, their short foraging range is usually less than 300 yards from the nest. Depending on the weather and available food, activity continues for around six to ten weeks and then the adults die, leaving their offspring to emerge and continue the cycle in the coming year.
Many local backyard enthusiasts enjoy and provide nesting for Mason Bees with great success. Providing nesting can be as simple as drilling holes into wood blocks, however without improved methods, mites in the Pacific NW generally overpopulate the holes and the bees will vacate after a couple of years. We enjoy sharing what we’ve learned about this gentle bee, and have many sites in the Puget Sound area that benefit from the free pollination and our fostering of the mason native populations.