The Buzz on Local Bees
Producing a bountiful harvest means keeping an eye on soil nutrition and moisture in your garden, but you might want to add caring for pollinators to your list of garden chores.
Many gardeners have noticed decreasing crops the last few years, as 90 percent of the wild honeybees that once pollinated our gardens have died. You could raise your own honeybees, but handling heavy, messy hives; performing mite and disease control; wearing protective clothing and tolerating bee stings demand a special dedication that, let's face it, few have the time or aptitude for.
But those are honeybees. North America has 3,500 other species of bees, known as solitary bees because they do not live in hives or have queens like honeybees. One of the easiest to raise is Osmia lignaria, also known as the mason bee, orchard bee, blue orchard bee or blue mason bee. They are immune to the mites currently decimating the honeybee population. Best of all, the males don't have stingers and the females don't usually sting.
"Their sting isn't like a honeybee's. It feels just like a little pinprick," says Oregon State University entomologist Rick Hilton. "They really don't sting unless you provoke them or grab them."
Where a honeybee will stay in its hive if it is raining or below 42 degrees, the mason bee will gather pollen in rain or cold once it hatches from its nest in spring.
Mason bees are also known as orchard bees because they are especially good at pollinating tree fruits, although some also like cane berries. They are smaller than honeybees, black in color with a bluish sheen. They only live for about eight to 12 weeks in spring, and they make neither wax nor honey, but concentrate on gathering pollen for their nests.
Mason bees do not make their own nests, but look for clean holes in wood left by beetles. Providing them with a nesting box within 300 feet of flowers with a nearby source of water for mud is all that is required. (They are known as mason bees because they seal up their nests with mud.)
It is possible to drill out a 4 by 4 with holes 5/16 in diameter, 3/4 inches apart on center, about 3 inches deep and just hang it on an east or southeast facing wall under a protective eave of a roof and wait for the bees to find it. (Some experiments suggest 5 1/2-inch long holes produce a better ratio of males to females.) Charring the entrance so it is black seems to help attract them. Detailed plans for attracting bees is available at the U.S. Dept. of Agriculture site: www.ars.usda.gov/
Mason bees will only use clean nests, so if you don't want to drill every year a number of companies make commercial nests. These vary from plastic or wood stackable blocks that come apart for easy cleaning, to holders for straws that can be easily replaced every year. If you purchase bees (available online), make sure they are suitable for our Southern Oregon climate.
Females plug the back of holes with mud, and then fill it with pollen and nectar before laying an egg and sealing the front of the tube with mud. This provides the larva with food to eat while it makes a cocoon and changes into a pupa. By the end of the summer the pupa becomes an adult, but stays in the cocoon until the following spring. Generally speaking, more than one egg is laid in each hole. It is essential the nest remains cool and dry, so moving it into a shed for winter is helpful. Make sure the nest remains oriented in the same direction as when it was hanging outside, so the bee doesn't die trying to break through the wrong end.
As long as you provide them with clean holes each year, the bees should keep coming back. The benefit to you is in better pollination for those orchard fruits that mason bees and people both seem to love. Cherries a la mason bee, anyone?