I thought I had been fooled enough by insect mimics, especially flies. Apparently not, after photographing this fly on Culver's Root on the weekend.
Unlike Robber Flies, this fly mimic, falls in the Syrphidae family along with the tiny flower flies that visit flowers. This particular syrphid fly, Eristalis flavipes behaves like a Bumble Bee, buzzing while flying and nectaring on flowers.
My first clue that this was a fly was the short antenna. Bumble Bees have much longer antenna. The other clue was that the black and yellow coloration did not match any of my bumble bee guides.
Robber Flies (Laprhia sp shown here), are also Bumble Bee mimics. Instead of visiting flowers like the Syrphid Fly above, they are voracious predators of other insects. Note the bearded face. They will perch on leaves waiting for their prey to fly by.