Whilst similar to E. tenax, this species has a more tapering abdomen in the male and pale front legs. The orange markings on tergite 2 of the abdomen are nearly always present but tend to be brighter in summer specimens.
Eristalis pertinax is a European hoverfly. Like Eristalis tenax, the larva of E. pertinax is a rat-tailed maggot and lives in drainage ditches, pools around manure piles, sewage, and similar places containing water with high organic load and low oxygen concentration.
Seen June 2023 in Chiswick House Gardens