I knew, after I saw the photos, that I had something I hadn't seen before--but where to start to find out what? I went to BugGuide.net, joined up, and uploaded a couple of the photos (here).
In almost no time I had an answer: male leaf-cutting bee of the genus Megachile, identified by Eric Eaton
I continue to be amazed that insect identification is possible. I'm still trying to let go of my vertebrate preconceptions. There are a number of advantages to keeping your skeleton on the inside--you can get a lot bigger, for example. But it does restrict the evolutionary pathways a species can follow. Looking at the world as a vertebrate I have a hard time getting used to the idea that relatively closely related species can vary enormously in what are to vertebrates very basic characteristics. Just one example: the mouth parts on this little cutie, compare them to those of the bee on scat I found in July.