Osmia lignaria

If your fruit trees are not producing as much as you would like but you don't want the bother of keeping a bee colony year round discover the advantages of the Orchard Mason Bee. Mason Bees are solitary and produce no honey or wax, spending their time gathering pollen and laying eggs instead. With a range of about 100 yards they will pollinate where you put them. Mason Bees are not agressive and will only sting if they get trapped in your clothes. Best of all they are not effected by the varroa and tracheal mites that are decimating the honeybee population.

The spring wake up call fruit trees get from mother nature also tells the Mason Bee it's time to get up and go to work. When the buds on your fruit tree start to flower the males will emerge from their cocoons first, then in a few days the females. In two days they will mate, then the males die a few days later. The females look for a place to lay her eggs, studies show they prefer a clean hole roughly 5/16" in diameter. Mason Bees are not destructive and will not create their own hole. It is important for the holes, called nesting cells, to be at least 5" deep for the proper male/female ratio and that the cell is relatively clean before the female will deposit her eggs.

Once the nesting cell has been located the female packs a small plug of mud at the bottom then flies from flower to flower collecting pollen and nectar for her young to feed on. The female eggs are laid first, at the bottom of the nesting cell, then another plug of mud. The adult female will repeat this process producing one to two eggs each day through early spring. In a few days the bee larvae hatches from it's egg and feeds on the pollen and nectar for the next 10 days. The larvae spins a cocoon and pupates. Towards the end of spring the bee transforms into an adult and waits in it's cell through winter for next spring before emerging to start the process again. If conditions are favorable Mason Bees should increase in population about 5 times from season to season.

Each spring we put out nesting blocks with paper liners in the nesting cells where our females lay their eggs. In the fall we bring the nesting in and remove the straws. The straws are slit open to be inspected to guaranty there are no parasites, we remove the mud plugs so it is easier for the bees to emerge, then we mark the number of bees on the end of the straw.

The bees are sold in units of 15 bees. We start shipping bees in February.

To be successful you will need to provide your Mason Bees a nesting block.
In the 15 years I have been using Mason Bees to pollinate 2 acres of plum and apple trees in the Pacific Northwest I have never seen any indication that the bees prefer one style of nesting block over another. Just make sure that the cells are at least 5 inches deep.

Your nesting block should be located near the fruit trees you want pollinated. On the side of a building is best but nesting blocks can also be mounted in the fruit trees.
There are 3 ways you can go.

1) Make your own Simply drill a series of holes in a block of wood. The holes need to be 5/16 inch in diameter and between 5 and 6 inches deep. The holes should be spaced between 3/4 to 1 inch apart. Do not use pressure treated wood or cedar.

2) The Straw Method Another method is using cardboard tubes with paper straw liners.
These straws are 5/16 inch in diameter and 6 inches long with a paper straw liner. The females fill the straws with their eggs that will hatch the following spring. When the temperatures drop in the late fall remove the straws with the eggs and put new straws in.

Take the tubes and bundle them together with a rubber band, cover one end with aluminum foil and put them in a can, a piece of PVC pipe or build a wooden box that protects them from rain. Using this system makes it easy to expand your area of coverage. If kept dry the cardboard tubes will last for several years.

3) Store Bought Most garden centers have a few styles of nesting blocks for sale and the only difference is looks. The important thing to look for is the depth of the holes. Anything less than 5 inches will produce mostly males and should be avoided.