The photo I posted earlier under Melonogaster has be niggling at my brain for 24hrs. The more I look at the photo regarding the face shape and antennae lengths leads me to believe that it is in fact a Pipizella specifically the long antennae species virens or maculipennis. Maculipennis is vey rare [59 records on NBN Gateway] and has not been recorded in Wales. Not even in the insect rich Gower where visiting researchers have failed to find it, or Carmarthenshire where a hoverfly survey has been documented. So I sent photos to R. Morris the head poncho of the Hoverfly Recording Scheme for his thoughts. His reply indicated that it was indeed virens/maculipennis but can't go any further from photos of this difficult species. Even though maculipennis is highly unlikely, I will have to record it as Pipizella virens agg. but it's still new for valley. Below are some photos I managed to take.