Unidentified Robberfly

[Heart-shaped World]

[Stubbs' intro to the family notes the long hairs on the thorax but no bristles, I did pause over this - obviously not long enough. I'm blaming the Codeine and keeping my head down. ]

That'd be intro to the genus then, sigh ... and all done in public!
It's the pills, honest!!

[oxycera]

I've checked against specimens. It looks ok for Leptarthrus - except for the the hind tibiae which should be extensively orange; so is it a trick of the light or back to the drawing board? I suspect its Leptarthrus with unusually dark hind tibiae - but don't take my word for it, I'm not a professional.

[Heart-shaped World]

Thanks Oxycera, for taking the time to do that.
I had looked at that late last night and was trying to see whether a shadow would fall over the hind tibiae, but just looks darker than I would expect from the descriptions.
If it gets to Leptarthrus, which I see nothing to contradict, then there are only the two to choose from (in Europe) and vitripennis has orange metatarsi (by both Stubbs/Drake and Geller-Grimm).
Chalk grassland is the larger habitat that it was found in.
Regardless, I'm very very much a novice and don't wish to try and make it fit!
(My suspicion is that you're bang on though, for whatever a novice's suspicion is worth )

Thanks again,
Darren.