Yellow-and-black banded overfills with a yellow face and the dusted thorax having a dull bronzy greenish appearance. The defining feature of the genus, the presence of hairs on the upper surface of the squamae (upper and lower lobes at the base of the hind margin of the wing adjacent to the halters) requires careful examination under good magnification.  Three species (S. ribesii, S. torvus and S. vitripennis) are the commonest yellow-and-black banded flower visiting overfills, but are difficult to separate.  Larvae feed on a variety of aphids.

Quoted from, Britains Hoverflies by Stuart Ball and Roger Morris (WILDGuides)