Eupeodes (probably) syrphid

For reasons I can't put my finger on, the diversity and abundance of flower flies, so strong last month, seems to have waned even as the number of flowers is on the upswing. Of course, maybe the dip is normal for early June... I don't have enough experience with the insects to have established a pattern in our neighborhood. But fewer is not none, and there is still more than enough syrphid activity around here to make carrying a macro-lens-equipped dSLR mandatory... if nothing else, to avoid the frustration that comes with spotting something intriguing and not being able to capture it. (My flower fly mentors have also suggested that I never leave home without an insect net and collecting jars.) Happily, I had the camera with me, so when I spotted this yellow-jacket-mimic syrphid performing the matchless flying agility that gives the insects their other common name, Hover Flies, I was in fine shape to photograph the hover-er in enough detail to be able to identify it. Or so I thought. These little yellow and black beauties turn out to be tricky, with lots of subtle details, many of which are not visible in an image, that must be examined before the critter can be assigned to the right species. The best that my friend and mentor Jeff Skevington from Canada could offer was that the syrphid appeared to belong to the genus Eupeodes, the Aphideaters. I really do need that net.