Common Flatface Pipizella viduata

This hoverfly appeared in my moth trap overnight. I initially keyed it using Ball & Morris but although I concluded from this that it probably was viduata, I was (and remain) confused by the choice in couplet 2a (p.221) between "Legs hairless" (Pipizella) and "Hind tibia with black hairs" (Trichopsomyia). The legs were clearly hairly, the hind tibia with short but obviously orange-yellow hairs. All photos I've seen of Pipizella show evidently hairy legs so I assume the "Legs hairless" is an error.

In view of the uncertainty using Ball & Morris (especially as it also says that Pipizella are best identified from male genitalia, and this was a female) I also ran it through Stubbs & Falk, and this led to viduata straightforwardly. Steven Falk's website hints at the possibility that there may be additional Pipzella species in the UK which aren't covered, so I also ran it through the key in Bot & Van de Meutter - this also led straight to viduata.

female Common Flatface Pipizella viduata showing head from side, tergites, hind leg, antenna and anepisternum, North Elmham (Norfolk, UK), 7th August 2025