Syrphidae
A large, cosmopolitan family in the order Diptera, suborder Cyclorrhapha, consisting of about 5,000 described species, also called hover or flower flies. Many are wasp-like, with yellow and black markings. The adults, which are fast fliers, feed on and pollinate many flowers. The maggots may be omnivores, phytophagous or feed on aphids, and are being used in the biological control of pests.
Reference
Schneider, F. 1969. Bionomics and physiology of aphidophagous Syrphidae. Annual Review of Entomology 14: 103-124.