After hatching, the larvae feed on aphids by piercing their bodies and sucking the fluids, leaving shriveled, blackened aphid cadavers. These predacious larvae are shaped cylindrically and taper toward the head. There are 5 to 7 generations per year. Syrphid larvae feed on aphids, and may also feed on scales and caterpillars. Eggs are laid mostly on the undersides of the leaf, near the primary veins, at a density of 1 to 10 per leaf.
Eggs turn black just prior to hatching.
The larva is gray to blackish with numerous hairs, but becomes reddish as it matures, starting on the edges and completing the change just prior to pupation. The pupa is uniformly black, small and flattened, and is attached to the leaf. They overwinter in sheltered places and become active in the spring. Eggs are laid on the undersides of leaves, usually near aphid colonies, and are typically yellow, spindle-shaped, and stand on end. Females may lay hundreds of eggs.