---

first you should make the differences between genera and if you look carefully to the wings you will note that the radial vein R4+5 is strongly looped at Merodon and straight at Cheilosia (if you know that it is very easy to make the differences between the two species).
Another difference you should observe at the third leg: the Merodon sp. have a very strong femur, with a large triangular projection.
take a look:
http://www.dipter...post_35995
http://www.dipter...post_47807

Amalia