~300 spp. in 43 genera in our area(1)
Keys to most NA spp. in(2)
Adults have bare humeri (postpronotal lobes), though these are often hidden by the concave posterior of their close fitting heads.
The larvae are primarily aphid predators. Some are generalists, others specialize in just a few species of aphids. Those in the Pipizini tribe specialize on gall forming aphids.
Adults exploit pollen and nectar produced by native plants having large inflorescences and flat corollae (e.g. Apiaceae, Asteraceae, Ranunculaceae and Rosaceae).
1: egg. 2 and 3: larvae. 4 and 5 puparia
Efficient biocontrol agents and minor pollinators.(3)
The classification of tribes is in flux; only Paragini and Toxomerini seem to be monophyletic. (Mengual et al. 2008
Larvae have pairs of locomotory organs on the first six abdominal segments. These are not true prolegs because they lack musculature and crochets.
Annual Review of Entomology
. Bionomics and Physiology of Aphidophagous Syrphidae
Flower Flies (Syrphidae) and Other Biological Control Agents for Aphids in Vegetable Crops