---

Well, there has been some changes in European Microdon taxonomy recently. Some species appeared to be cryptic species as so with Microdon analis. The adults can not be recognized but differences can be found in the structure of the larval skin. Also different ant host species are used by the larvae.
So probably your fly is Microdon analis but Microdon major can not be excluded.
If you observe a Microdon it is always wise to look in the direct neighbourhood of the fly if you can find a ant's nest. Microdon analis lives together with Lasius (probably only Lasius platythorax) ants with nests in dead wood. Microdon major with Formica nests in dead wood (Formica sanguinea amongst other Formica species).
Most of the time the flies don't struggle very far from the host's nest.