#1
I found this Cheilosia yesterday (28.03.2020) visting Prunus spinosa, near a mixed forest (especially oaks and pines, some spruces and beech. Using the key of Bot & van de Meutter (2018), I get to C. morio. The authors describe it as a relatively large Cheilosia (8-10 mm) but they mention that there is another very similar species described in Europe which is smaller (and until now is also listed as C. morio).
This individual here was quite small, I think, maybe 6-7 mm.