---

June 08, 2010, Naro-Fominsk, Moscow region, Russia. On and near a dead fallen aspen (same location as for Pseudoseioptera demonstrans). Numerous males (wing length 7 to 9.5 mm) and a single female (wing length 8.5 mm) were observed and collected. Very characteristic appearance, with glossy-black body, darkened wings, yellow halteres, yellow patch in upper part of pleurae (in the field looks much like a second pair of halteres), and greyish-tomentose lower part of pleurae, coxae, and trochanters. Yet a closer look revealed that some males have wings more clear while others are with strongly infuscated wings. Examination of genitalia showed that males with more clear wings are Gnophomyia viridipennis, and those with strongly infuscated wings are Gnophomyia acheron (described from East Palaearctic, recorded from the Russian Far East and West Siberia, in West Palaearctic at least from Finland in Stary & Salmela, 2004; I don't know if it's known from European Russia). There's probably a third species, too, more common G. lugubris, very similar to viridipennis, so further examination of location/genitalia of collected specimens is needed.
Here's what I believe to be G. viridipennis.