Mason Bee Mania

A self-professed "Bee Nerd", Lori Bergmark enlightened us on Mason Bees.  Lori lives in an area where they do not allow honeybees (silliness!), but she has managed Mason Bees on her property, and no one is the wiser.  Except us.  Lori gave us a glimpse into the life of the Mason Bee.

Mason bees are in the genus Osmia.  Species include the native Osmia lignaria, (Orchard Mason bee), O. atrinventris, (Blueberry bee, and the Japan native O. cornifrons (Hornfaced bee). In 2014, Lori worked with the Blue Orchard and Hornfaced bees.

Aptly named, their nests are mud compartments in hollow stems, reeds, or existing holes left by wood boring insects, or in snail shells.  They are not destructive. For their nests, they collect materials such as mud, leaf pulp and gravel.

No Monarchy
Solitary and queen-less, Mason bees do not make honey, but like many other bees, make a pollen ball, and lay an egg on top of the pollen.

Each Kid Has Their Own Room
The female Mason bee creates a mud partition for each egg and pollen ball.  This is done in an orderly fashion with the girls in the back and the boys in the front.  Once they are all snug in their rooms, she plugs the entrance.  After a month-long larval stage, they spin a cocoon.

Mason bee cocoon

The new bee emerges in about March, and just hang until the weather warms.  The males emerge first and go get some food, then the females come out.  Mating occurs and the males die in spring.  Then the females collect pollen and the process starts again.

Mason Bee Behavior
Mason bees are not aggressive, and forage within 300 feet of their nest.  So, if you see mason bees in your yard, you can be sure they are nesting pretty close by.  They need a source of mud to build their nests, and better if it contains more clay than sand.

Power Packed Pollinators
Mason bees are amazingly efficient pollinators.  They can pollinate fruit trees 3 times better than Honey bees.  Unlike Honey bees, Mason bees will fly during cool, cloudy weather, however, they fly more randomly among the trees.  Honey bees are more systematic pollinators, so the combination of Mason and Honey bees in an orchard seems to be the best pollinator combo!

set up for Mason bee pollination in Ukraine

Managing Mason Bees
A newish concept in the United States, the Hornfaced Mason bee has been managed in Japan since the 1940's.  80% of apples in Japan are pollinated by the Hornfaced bee.

If you want to try to manage Mason bees, you will need a nesting area.  For this, you can make it yourself or purchase one.

Here is a link to the U of MN Bee Lab with instructions on how to make super simple native bee houses:
http://www.beelab.umn.edu/prod/groups/cfans/@pub/@cfans/@bees/documents/asset/cfans_asset_434476.pdf

In the fall, although not strictly necessary, Lori brings her cocoons in and keeps them in her fridge until they break dormancy (one spring it was early and Mason bees were flying around the refrigerator). Bringing in the cocoons allows you to clean out the nests and minimize the incidence of disease.  You also need a supply of mud, lots of nearby pollen plants, and a fresh water supply.

Not Managing Mason Bees
Of course, you can just attract Mason bees to live in your yard naturally.  You need some undisturbed areas, smallish brush piles, dead wood and fibrous materials. Provide diverse pollen plants nearby, areas of exposed soil and mud for nest building, no pesticides, and you're set to attract some native bees!  Create a "not so tidy" garden!
~M.F.