Corn Earworm

Helicoverpa zea

Corn earworm larvae.

Adult corn earworm moth.

There are 4-5 generations of corn earworm in Kansas, with moths first appearing in late April or May and infestations of corn can occur anytime from early June to the first frost. Feeding by larvae causes ragged injury to leaves in whorl stage corn, but damage during this period is usually limited to isolated plants. Infestation during the silking period results in damage to the tip of the ear. Early planted corn will usually escape heavy infestations. Attempts to control ear damage with insecticides are impractical in field corn, even when a majority of ears are infested. Control is difficult because eggs are laid on freshly emerged silks which will not be protected with insecticide, and hatched larvae can tunnel into the tip of the ear beneath the husk without contacting any insecticide. There are some transgenic corn hybrids YieldGard (Mon810), Agrisure (Bt11) and Herculex (TC 1507) and others that claim some suppression of corn earworm damage.

Please consult the most recent Corn Insect Management Guide for control options.

Page last updated 3/28/2024 by J.P. Michaud.