How Big Can a Bee Get?

I thought maybe I had seen the world's largest this morning at the college, but I did a little research when I got home and found out I was wrong.  This Carpenter Bee landed on the Rabbitbrush near the entrance to the FRC library, and it was very impressive.  It didn't pay much attention to me as I moved in close with my camera.

I learned that the largest known bee was first seen by the naturalist Alfred Russell Wallace in what is now Indonesia back in 1859, the same year Darwin's Origin of Species was published.  The bee was not seen again until 1981 when an American biologist found one on the same island.  As far as he could tell, the natives were not aware of this bee, so it has no "common" name.  The technical name is Megachile pluto.  It is slightly longer than 1.5" and has a wingspan of 2.5".  Next time I visit a Carpenter Bee habitat, I'll bring a ruler because I think ours are close to that size.  By the way, Carpenter Bees are aptly named.  They eat through wood with ease and build their nests in any large beams that are convenient to their hunting grounds.  There are many living in or on the wood of the Campus Center at the college as well as the main buildings at Oakland Feather River Camp.  I've never been stung or bitten by these, so, for now, I find them quite fascinating.