We had our biggest snowfall of the winter today. Actually, it was the only significant snowfall this winter. We’ve had stretches of very cold weather, without any snow. Two days ago it was sunny and warm (60 F /15 C) out and the bees were very happy. Today is the first day of spring, and they are clustered in the hive.

As such, a good time for another post on a native bee species: mason bees. These hard working bees are smaller than honey bees and prolific pollinators. My friend Tammy gave me a book on these bees for Christmas, and it inspired me to put a Mason Bee House on my birthday list.

My top bar hives in the cold this morning (March 21, 2018). ©Erik Brown

For the taxonomically inclined, mason bees are part of the family Megachilidae. These mostly solitary bees tend to build their nest from a characteristic substance. Thus mason bees use mud (masonry), leafcutter bees use bits of leaves, carder bees use plant or animal fibers, and resin bees use plant resins. A breakdown of the biological taxonomy is shown in the following diagram. I highlighted the mason bee hierarchy in yellow, an idea I borrowed from a post on L’apiario di Luca (Luca’s apiary) on the honey bee taxonomy.

Mason bees are in the Genus Osmia. ©Erik Brown

The genus Osmia contains over 500 species of mason bees throughout the world, with around 130 found in the U.S. and Canada. See this Buzz About Bees post for a more complete discussion of mason bees. The genus Anthidium represents carder bees, and the genus Megachili represents leafcutter bees. We will save these other Megachilidea bees for the subject of another post sometime.

Mason Bee Revolution

Co-authored by the founder of Crown Bees, this book is a practical guide to raising mason bees for home or commercial pollination. Mason bees are smaller than honey bees and very gentle. They are so good at pollinating fruit trees that some species are referred to as orchard bees. One mason bee can pollinate as well as 50 to 100 honey bees. Hence the subtitle of the book: “How the hardest working bee can save the world one backyard at a time.”

A blue orchard bee mason bee (Osmia lignaria) from the Forest Service site.

Mason bees hibernate over the winter and emerge in the spring for about six weeks as an adult. The males mate and then quickly die off, while the females nest in small holes found in stone, houses, or trees. The female lays a single egg in a pollen ball placed at the back of the hole, and then seals this with a small wad of mud. This is repeated until the hole is full, with male eggs generally placed nearer the entrance (since they emerge first and are more expendable). The egg hatches into a larva, which consumes the pollen ball. Eventually the larva spins a cocoon to turn into an adult bee.

Standard Mason Bee House

My darling wife was kind enough to give me a mason bee house for my birthday. The Welliver Outdoors Standard Mason Bee House, shown in the picture, is a box with about 100 removable tubs made just for mason bees. I attached the eye hooks and will secure it to a tree branch next weekend. A key feature, according to the book, is to have a way to remove the cocoons in the Fall. Mason bees are suseptable to parasitic wasps and pollen mites, among other pests, and in the wild the majority of eggs are killed or otherwise never grow into adults. So removing and cleaning the cocoons is recommended to obtain the best survival rate.

Suppliers like Crown Bees and Brushy Mountain sell cocoons of overwintered mason bees. You place these out in the spring to ensure a good starting population, and they use your mason bee house to make the next generation.  There are different kinds of mason bees for the east verse west coast. I didn’t purchase any cocoons, as I am hoping that some of the many native bees in our yard are mason bees. We will see if this is true or not.

You can’t get blood from a stone

This proverb is used to convey the difficulty of getting something from a person or object unwilling or unable to give it. For example, money from someone who is broke, or pity from someone who just doesn’t care. The saying appears in my favorite book of proverbs, though The Phrase Finder site has a good discussion of the saying as well. It originated as an Italian proverb and appeared in an English-Italian translation book in the 1600’s.

Since there rather few sayings with the word “mason” in them, I went looking for the word stone as a stand-in for mason. This seemed like a good fit, especially after changing the word blood into honey. Mason bees do not produce honey; they only collect the pollen and nectar as needed for themselves and their eggs.

May you prosper and find honey.