It is a species of Leptocera (see 8 scutellar setae, long setose first costal sector, strong ventral preapical bristle on mid tibia and strong ventral bristle on mid basitarsus) but I am not able to recognize if it is the common Leptocera fontinalis (Fallén, 1826) or the rarer and more northern species Leptocera finalis (Collin, 1956). The less curved vein R4+5 indicate that L. finalis is more probable, but as I cannot see the 2 subapical setae on posterior side of mid tibia (being markedly longer in L. finalis than in L. fontinalis) I am not sure about the identification.

Thus, I suggest to name the species as "Leptocera sp. cf. finalis (Collin)". These Leptocera species have phytosaprophagous larvae developing in rotting vegetation and adults can be often collected in numbers on accumulated wet decayed leaves, detritus, grass etc., both in open and wooded habitats.