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There are 3 species: R. borealis, R. campestris, R. rostrata. A female R. borealis can be ruled out because the arista bears no long hairs, the snout is not short and strongly curved, and the tibia 3 has no black tip. (The male would look different, having a black thorax and scutellum, but your picture shows a female.)
As Juergen pointed out, a typical R. campestris has a dark abdomen edge, because (beside the hind margins) the side margins of the tergites are darkened. Legs, face, and scutellum are duller and darker in colour than in the third species R. rostrata. In the latter species, the abdomen edge is not darkened, the thorax is somewhat more bluish, and face, legs, and scutellum are orange-yellow rather than dull brown. Therefore I would call your fly R. rostrata. The only uncertainty is that the snout seems rather long and straight (like in R. campestris) instead of shorter and a bit curved downwards. However, the non-dark abdomen edge is stressed in all descriptions, so R. rostrata should be OK.
Regards, Sundew