Agapeta zoegana is a species of moth known as the sulphur knapweed moth and the yellow-winged knapweed root moth. It is used as an agent of biological pest control against noxious knapweeds, particularly spotted knapweed (Centaurea maculosa) and diffuse knapweed (Centaurea diffusa). The adult lives for only a few days, during which time the female lays eggs on stems and leaves. The larva, a root miner, moves to the root of the plant and tunnels through the cortex as it feeds. This causes moderate damage to the plant. Flight is from May to August from dusk, and is attracted to light.