What is "pyrophaena"

'Pyrophaena ' is a subgenus of the hoverfly genus Platycheirus distinctive enough to sometimes treated as a separate genus in its own right. Indeed a recent study of the phylogeny of the subfamily Syrphinae found it to be closer to other certain other genera – Rohdendorfia, Syrphocheilosia and Spazigaster. Since only a few species were sampled the true systematic structure must await a more thorough survey of Platycheirus and related genera.