Philhelius citrofasciatus
Philhelius citrofasciatus is a species of hoverfly found in grasslands from Ireland to western Siberia. The larvae live in Lasius ant colonies where they feed on the aphids tended by the ants. Prior to 2018, it was known under the genus name Xanthogramma, a junior synonym.
Description
For terms see Morphology of DipteraWing length 6·5–10·25 mm. Legs yellow coxae and trochanters black. Femora and tibiae 3 are completely pale. Yellow marks on tergite 2 linear. Tergites 2–4 with subequal yellow marks.
See references for determination.