Globetail syrphid

Several years ago, we got a load of cheap dirt to fill in some holes in the yard, and while the lesser soil did the job, it also, unbeknownst to us, contained something we hadn't expected: a collection of Lesser Celandine tubers... lots of Lesser Celandine tubers. So we've been left to fight off a botanical invasion, and though we're losing the battle, there have been benefits. Ficaria verna sports handsome, yellow, Buttercup-like blossoms that are pollinator magnets. As I watched the blooms, I spotted a new kind of flower fly, and after a lot of study, and an e-mail to my mentor Jeff Skevington, I learned that I was looking at a syrphid belonging to the Globetail family. They're tricky to get down to species from a photograph alone, so I'll have to start bringing my net and examining the insects under the microscope.