---

Hi Sundew,

For a key you'd need Papp 1998 genera key in manual of Palaearctic Diptera and in this case the key by Czerny which has a key of Heteromyza (Thelida & Heteromyza). On account of the narrowing frons and the face being narrower then the frons: Heteromyza rotundicornis. Although I'd wait for Andrzej Woznica, he's the European expert.

Kind regards,

Ectemnius