Phaonia, yes. errans, no. P. errans male has the frontal orbits touching and the hind femur yellow (see http://www.dipter...post_12297).
I'd say this is more likely Phaonia perdita.
If it was from Britain, I'd say send it in as perdita, but I don't know if you have other species in Russia that could be confused with it. Maybe Kahis can help?