RES Handbook Vol 10 Part 1. Diptera. Syrphidae.

FLIES of the family SYRPHIDAE are commonly known as " Hover-flies" and "Flower-flies," the former popular name having reference to their frequent mode of flight and the latter to their fondness for flowers. The males are habitual hoverers, often appearing almost motionless in the air, although capable of exceedingly swift movement when disturbed . In body coloration SYRPHiDAE are often entirely black or dark (e.g., Cheilosia and Pipizella), but in many genera the thorax bears yellow or orange stripes or other markings, and the tergites are ornamented with more or less conspicuous white, yellow or orange lunules , spots or bands.