Sorghum Headworm

Helicoverpa zea.

Also known as corn earworm

Although larvae of this moth prefer corn, they will infest sorghum heads between fowering and early stages of seed fill. The head capsule is light brown and the body color varies from pink to green to brown with light and dark stripes along the length of the body. Larvae can be 1½ inches long at maturity.

Infestations are more common in southern Kansas, and sorghum is vulnerable to infestation from bloom through milk stages. One to two larvae per head can result in approximately 5 to 10 percent yield loss. The average size of larvae at detection is a key consideration, because less will be gained by treating older, larger larvae, and they are harder to kill. The decision to treat should balance the expected yield and crop value against treatment cost and the amount of damage that can be prevented. Control is more difficult in grain sorghum cultivars with tightly clustered berries.

New products have become available for headworm control (Heligen and Fawligen, for corn earworm and fall armyworm, respectively) that have viruses as their active ingredients. The biological agents are highly specific to their host insect and will kill only that species - all other insects in the field will act as passive vectors that help spread the disease and cause secondary infections.

Please refer to the most recent version of the Sorghum Insect Management Guide for specific control recommendations.

Page last updated on 11/24/2024 by J.P. Michaud.