Rhagionidae is a small family of orange/black Snipe-flies. There are 6 species in Britain, 4-species have black wing stigma and two have pale stigma. I photographed the two commonest species at Blaencaerau today.
Rhagio scolopaceus[Downlooker Snipe-fly] is one of 4 species of Rhagionidae with black stigma on the wing. Of the three other species "notatus" is rare (132) and only recorded in Glamorgan down the Gower, "strigosos" is very rare (84) and not recorded in Wales. The other common species "lineola" can be separated from "scolopaceus" in being much smaller and has no clouding around the cross-veins on the wings.
Rhagio tringarius[Marsh-snipefly] is one of 2 species of Rhagionidae that does not have a black stigma. The other species "annulatus" is very rare (23) and has not been recorded in Wales. The way to tell "tringarius" from "annulatus" is that it has yellow hairs covering the thorax [as seen above] rather than dark in "annulatus" which makes the thorax look grey.