Two very different colour forms exist - the 'type' form with a white tail and broad yellow collar (a superb mimic of the Tree Bumblebee, Bombus hypnorum) and the all-buff form 'oxycanthae' (a mimic of carder bumblebees like B. pascuorum). The latter is very similar to another hoverfly, the late-flying Arctophila superbiens but lacks the distinct wing clouds of that species.

Found in ancient woodland and other places with old trees.

Adults fly from April to September but are most often seen in May and June visiting the flowers of Hawthorn, Bramble and Hogweed. Females are often seen flying slowly around stumps and the bases of old trees in shaded locations.

The larvae develop in wet decaying tree roots and old rotten stumps, typically of broadleaved species.

A widespread but localised species with most records coming from the southern half of Britain.

Status in Leicestershire and Rutland not known.