Corn is the preferred host plant of corn earworm, which has over 100 alternate hosts. In the mid-west, corn earworm is typically a late season pest of sweet corn, though field corn is also a common host of this pest. Male moths are typically lighter in color than females. Females lay from 350 to 3,000 yellowish-white eggs singly on corn silk and foliage. Before hatching, eggs develop a reddish-brown band.
Larval coloration ranges from brown to green to pink.
Corn earworm larvae can also be distinguished from other caterpillars by the black tubercles that cover their bodies, the 3-4 stripes running dorsally down their bodies, and their tan heads. Corn earworm larvae typically feed within the ear on developing kernels. Larvae are cannibalistic, so usually only one is found per ear. Life Cycle Corn earworm has three to four generations per year, though Minnesota only experiences two. Moths emerge from overwintering pupae in early spring and begin to migrate northward from the Gulf States.