Dirt, really good info.!
Thought I would mention, there are other bee-look-alikes, such as the Robberfly, Southern Bee Killer.
I've had a few incounters with them buzzing at me, usually if I get in the way of them mating or stalking their prey. They like to attack their prey mid-air.
I've learned to recognize them by the way they hang out on plants, instead of browsing the flowers. But now I see them because I think they look cool in their big dark shades.
Southern Bee Killer (Mallophora orcina)