Yellow Crane Dicranomyia lutea
This was keyed using the Stubbs BENHS book and it led to lutea fairly comfortably, if a little circuitously. The text says, "females are very difficult to separate without considerable experience" and so far I don't have any previous experience with this species and very little with the genus. Maybe I should regard this ID as tentative then, but I don't see any reason to think it isn't lutea. The wing was 7.2mm long.
female Yellow Crane Dicranomyia lutea showing wing, Wendling Beck Environment Project (Norfolk, UK), 14th July 2024