Backyard Nature Wednesday: Mason bees

Mason bees of the genus Osmia are a type of native bee that is very common throughout most of the United States. They are typically a bit smaller than a honeybee and are solitary like most native bees. There are about 140 species of mason bees in North America, many of them, including the ones I see in my yard, have a metallic blue color. The males do not have a stinger and the females only sting if trapped or squeezed. 

In the wild, these bees lay their eggs in small natural cavities, plugging the holes with a bit of mud, thus their name, mason bees. They are also quite happy to nest in human-provided habitats.

This is a typical kind of mason bee habitat which I had had hanging in a tree in my backyard for several years. Eventually, time and the weather had their way with the structure and it became so dilapidated that, last spring, I decided it was time to junk it. I took it down and set it on my potting table, intending to dispose of it later. And promptly forgot about it.

Recently, I was clearing off and rearranging things on my potting table and I came across the bee habitat again. It had been hidden from human eyes behind pots and other paraphernalia, but the bees had still managed to find it. They were not at all deterred by its condition. They continued to use the tubes as sites to lay their eggs. 

There were about twenty-five of the tubes that were in use or had been in use as nesting places and the bees were continuing to visit the site. Soon, more of these tubes will be plugged with mud by the masons.

Mason bees of all kinds are important pollinators, especially for fruit trees. Some gardeners hang their bee habitats in their fruit trees to encourage the bees. But I can testify that even the habitat gets lost behind pots on a potting bench, the clever little bees will still find it!