COLUMBIA, Mo. – A new University of Missouri Extension publication offers corn growers help in identifying Missouri’s newest corn pest, the corn leafhopper.

MU Extension state crops and forage entomologist Ivair Valmorbida says “Biology and Management of Corn Leafhopper” offers insights on corn stunt disease and strategies to manage this new pest.

In 2024, MU Extension specialists confirmed the insect in corn crops in 13 Missouri counties. Corn stunt, a disease carried by the corn leafhopper, can cause 100% yield loss.

The free downloadable publication, written by Valmorbida and MU Extension state plant pathologist Mandy Bish, includes photos of the leafhopper and crops damaged by corn stunt. Initial corn stunt symptoms are chlorosis and/or reddening of leaf tips. The disease can result in deformed grain, loose kernels and short stalks.

Leafhoppers feed on corn crops with their piercing-sucking mouthparts. During feeding, they produce a honeydew that favors the growth of black sooty mold. The corn leafhopper can also transmit four pathogens associated with corn stunt disease.

The guide gives scouting and management techniques. As with other pests, Valmorbida recommends scouting corn fields throughout the growing season. Corn leafhoppers move rapidly within and among cornfields and fly or jump away when disturbed.

Visual scouting may not be effective when insect numbers are low. Valmorbida suggests assessing presence by using a sweep net or a battery-powered vacuum with a pantyhose stocking over the funnel.

Once found, producers should use multiple practices to reduce the population and sources of disease inoculum, says Valmorbida.

Valmorbida gives four tips to reduce the risks of infestation:

• Plant early.

• Consider insecticidal seed treatments that can protect up to V3 growth stage.

• Remove volunteer plants that may serve as a green bridge, or alternative host, for the corn leafhopper and as a reservoir for the corn stunt pathogens.

• Consider foliar insecticides if corn leafhoppers are present before the V8 growth stage.

Download the publication at https://extension.missouri.edu/publications/g7109.

Photos

https://extension.missouri.edu/sites/default/files/wysiwyg/Extensiondata/NewsAdmin/Photos/2024/20241126-leafhopper-1.jpg
Corn leafhopper, found in Missouri for the first time in 2024, carries corn stunt disease, which can cause up to 100% yield loss in corn crops. Photo by Lucas Bonuma Severo, University of Missouri.

https://extension.missouri.edu/sites/default/files/wysiwyg/Extensiondata/NewsAdmin/Photos/2025/20250107-corn-stunt-1.jpg
This 2024 photo of corn from fields in southwestern Missouri shows the difference between normal ears of corn and those affected by corn stunt disease. Corn stunt disease results in deformed grains and lower yields. Photo courtesy of MU Extension agronomist Tim Schnakenberg.