This red-legged fly is one of the many flower flies grabbing some breakfast. It is from the genus Chalcosyrphus, which has many members that resemble wasps not only in looks but behavior. I was relieved when I read this, for my first impression when I saw this insect was that it was indeed a wasp! The tiny paired antennae, however, are typical of flies. A trip to http://www.bugguide.net/ confirmed it was indeed a fly.
This yellow-jacket-mimicking fly is from the genus Temnostoma. It may be T. vespiforme, which is a highly successful species found not only in North America, but also in Asia and Europe.
I suspect this fly is the same species as the one above. It was totally focused on the white rose in which it had buried itself. As I watched, it was using its front two feet to scrape pollen from the anthers into its mouth at such a speed one would think it had been starving. Still photos couldn't capture its frenzy, so I tried a video.