Fly was perched on a blade of grass in direct sun, making for burnt-out photographs, but also making its blue iridescence visible.
In the last photo, the fly had moved over to a sprig of juniper in the shade, so head features more visible
aka "blue-banded flower fly" http://bugguide.net/node/view/1083349/bgimage
http://syrphidae.myspecies.info/taxonomy/term/152/media