In a recent scientific paper I scanned, the headline touted members of the housefly congregation as the dominant pollinators of Arctic flowers. We're a little south of the Circle, but in the chilly days of late winter, most of the pollination duties are taken up by various Diptera. There are some flies I know pretty well, but this isn't one of them... and a quick run-through of possibilities at BugGuide.com didn't yield any likely candidates. I'll have to do more work on the identification front and maybe send the photo to the experts, but in the meanwhile, the unnamed fly is on the job of transferring pollen from one Winter Aconite blossom to the next. I'm guessing it'll do crocus flowers as well. In this lean time of the year, you usually can't afford to be too picky.