I was told this is a Deer Fly, but they appear to have vertical stripes on the abdomen (in the pictures I've seen), and this one clearly has horizontal stripes on the abdomen. Photographed in Eastern Iowa. It has been extremely wet and humid for the past few months.
This is not a deer fly, but is a flower/hover fly (family Syrphidae); likely in the genera Parhelophilus (see http://www.pbase.com/tmurray74/image/32542524) or Helophilus (see http://www.cirrusimage.com/Flies/Helophilus_fasciatus_02.jpg). These do not bite, and are harmless to humans. The larvae of some syrphid flies are predaceous on aphids.
Thanks! I didn't realize flower flies could be so big. I had little tiny ones that sat on my spiderwort but had never seen such a big one. Thanks for the ID help!
