I took this Doros profuges locally yesterday. A lovely little fly I'd not come across before. I wonder whether this species is nowadays a 'rarity' (the word used by Stubbs and Falk). Since that was published we presumably have much more information.
Anthony - have another look at the abdominal markings and overall shape - this looks to me much more like Xanthogramma citrofasciatum!
You may be right Tony - what caught my attention were the extremely strong chocolate markings on the wings, far stronger than those in the Xanthogramma illustrations in Stubbs and Falk - their remark on X. citrofasciatum is 'wings clearer.' However I've since found new photos of X. citrofasciatum showing very dark wing markings and scutellar, thoracic and abdominal markings identical to mine. So X. citrofasciatum it is. This record will find its way onto the Wiltshire database and to iRecord in due course.
I was so struck with this attractive creature that having cooled it down to photograph it I let it go.
Maybe look at X pedisequum too as the markings look bright yellow rather than the primrose yellow of X citrofasciatum? I've seen both species and the colour difference is distinct.
I've looked at both, and on the whole I stick with X. citrofasciatum, based on the shape of the markings, which are more angular than the more rounded markings on X. pedisequum. The thoracic markings seem to confirm this. The extent of the chocolate markings on the wing worries me, I must admit, but in that regard I'm working from memory only.
On a further note, the legs of my specimen are strongly orange, whereas those of X. pedisequum are predominantly yellow - as can be seen when you look at photos of both species on Diptera.info. The hind margin of the scutellum has the same colour. So far as the wing markings are concerned I'm led to suspect that the illustration in Stubbs & Falk was drawn from an untypical specimen.