Syrphid larvae tend to prey primarily on aphids, mealybugs, scale insects and related Homoptera . The adults, which have a yellow and black striped abdomen and look superficially like a small bee, feed on the nectar and pollen from flowers. The adults seek colonies of aphids and lay their eggs nearby. The headless, legless, maggot-like larvae tend to be pale yellow to light green in color. The life cycle, from egg to adult, usually takes two to four weeks.
Several generations occur each year.
Although normally thought of as aphid predators, many syrphids probably have a wider host range. In Europe, one species is known to commonly feed on small caterpillars. In Wisconsin, one very common species, generally considered an aphid predator, is also an important predator of cranberry tipworm, which is the larva of a small midge that attacks the cranberry plant. As the name implies, the larvae of most gall midges feed within plant tissue, creating abnormal plant growths called galls. However, the larvae of a large number of species are predaceous and some are even reported as parasitoids.