Acrosathe annulata

I photographed this striking diptera yesterday unlike any I've seen this year. I thought it may be easy but there are several confusion species so keying out was necessary. Here's the process and a photo of the animal:

Wing venation keyed out with the cell between the discal cell and the hind wing margin closing.
Pale halteres, silver hairs including the face, first antennal segment as wide as the third all fit for Acrosathe.
Femur 2 without anteroventral bristles tells it apart from Acrosathe baltica

Acrosathe annulata

Acrosathe annulata