Sorghum headworm or corn earworm, Helicoverpa zea.
Although larvae of this moth prefer corn, they will infest sorghum heads. 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. 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.
Please refer to the most recent version of the Sorghum Insect Management Guide for specific control recommendations.
Page last updated on 10/31/2013 by J.P. Michaud.