Conops flavipes?

I think this is a member of the family Conopidae, or thick-headed flies, the larvae of which are parasites on bumble bees.  The maggot eats the abdomen contents, breathing through its skin and then its hind spiracles until the poor old bee collapses.

The adults eat pollen

Found on Ragwort in Bruaich Jerich

Some information:
http://www.insectoid.info/flies/thick-headed-flies/conops-flavipes/

Carl