|Western Blue Orchard Bee, photo from Crown Bees|
It's a little late here the south central US to start on housing for mason bees, but it's about the right time in the more northern US states and Canada. And it's really as easy as drilling holes in boards.
Mason bee is a common name for species of bees in the genus Osmia, of the family Megachilidae. They are named from their habit of making compartments of mud in their nests, which are made in hollow reeds or holes in wood made by wood boring insects.Species of the genus include the orchard mason bee,Osmia lignaria, the blueberry bee, O. ribifloris, and the hornfaced bee, O. cornifrons. The former two are native to the Americas and the latter to Japan, although O. lignaria and O. cornifrons have been moved from their native ranges for commercial purposes. The Red mason bee, Osmia rufa, is found across the European continent. There are over 130 species of mason bees in North America that are active from spring through late summer.From Wikipedia, the free encyclopedia; http://en.wikipedia.org/wiki/Mason_bee
Encouraging mason bees in your yard can purportedly be a great alternative to keeping honey bees, especially in an urban environment ass they are even less likely to sting than honey bees. some day I will have honey bee hives, but I think I will still get a mason bee house going this spring and see what happens. The boards I have out back are 2x4s and not very well suited to making a mason bee house and I never got to the hardware store to see about getting something larger so I never got a house made. Subsequently, I have missed the chance this year to get some orchard mason bees because they only have one generation per year, but since there are varieties active throughout the summer I may still have a chance to get my own 'hive' going. For more information on mason bees and making housing for them, check out this pdf from University of Arizona. Interesting fact: Mason bees are being cultivated in the southwestern US to help combat invasions of Africanized honey bees because the honey bees cannot live in the same type of housing.