The Nature of Things

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. Rece...