---

Cheilosia flavipes (female) for sure - there are no other possibilities:
- bare eyes, not haire facial knob, completly yellow legs, black stutellum without bristles, broad eye rings, size >=10mm, date around 1 may in Germany, rounded tip of wings, yellow 3rd segment of antennae

I looked also at the shape of face of my specimens (1 may 2012 - Reda,Poland) - the same.

Males of Ch. flavipes are a little bit more difficult to determine because of haired eyes and blackish femora...

Cheers
Robert Zoralski