Mason Bees

Hornfaced bee Osmia cornifrons- from Wikimedia

      -By Jennifer Ailor, Springfield Master Naturalist

Mason Bee "house"

This spring I purchased two mason bee “houses” from Gardeners Supply Co. and check them nearly every day for activity. You’ve no doubt seen their nests of mud inside hollow reeds or holes in wood. The bees are terrific pollinators and may visit as many as 1,000 blooms a day or 20 times more than a honeybee. I placed one of the bee houses on the southwest corner of my barn near the garden and another at the house, where I have lots of flowers and flowering shrubs.

According to Wikipedia's article on the subject and other sources, mason bees are in the genus Osmia of the Megachilidae family. There are more than 130 species in North America alone, active in temperate zones from spring through late summer. Mason bees are solitary. Every female is fertile and makes her own nest in a hollow cavity created by a wood-boring insect or bird or in hollow reeds. They don’t produce honey or beeswax.

Males hatch first and then hang around potential nests waiting to mate. Once that’s occurred, the female backs into the hole and lays an egg on the top of a mass of pollen/nectar she’s collected. She then creates a mud partition, which fills in the back of the cavity. She’ll continue laying eggs until the cavity is filled, then plug the entrance to the tube and seek another nest location.

By summer, the larva has consumed all of its provisions and begins spinning a cocoon around itself and enters the pupal stage. The adult matures in the fall or winter, hibernating inside its cocoon until it emerges in the spring.

If you’d like to order a house, Gardeners Supply has them for $18.95 each. You also can build your own. Here are two links to sites that have lots of information about building nests and about mason bees in general: http://masonbee.blogspot.com/ and http://www.crownbees.com/mason-bee-tubes-and-straws-which-are-best/.

Editor's Note:
We have a large supply of various bamboo-like reed grass which are cut annually from the beautiful Grass Garden at Close Memorial Park.  They are perfect for the job and if you are interested in making your own mason bee house and are in the Springfield area, I will be glad to supply you some.  It just takes some reed segments and a can.

I Bee-live in Pollinators- Quick and cheap