Missouri Cornfields See Less Leafhopper Damage in 2025

By Blake Jackson

University of Missouri Extension’s in-field research in 2025 cornfields showed notably less damage from corn leafhopper compared to 2024. While this is encouraging news, MU Extension state crops and forage entomologist Ivair Valmorbida remains uncertain about the cause. “It is possible that corn leafhoppers arrived later in the season compared to 2024, as they do not truly overwinter in Missouri,” Valmorbida explains.

The invasive pest first appeared in Missouri corn in 2024, carrying corn stunt disease, which can lead to severe yield losses. Corn leafhoppers are often transported by southern winds following weather events such as hurricanes.

In 2024, corn stunt was confirmed in multiple Missouri counties including Gentry, Knox, Boone, Pike, Lincoln, Warren, Gasconade, Osage, Morgan, Bates, Laclede, Barton, Lawrence, and Christian. In 2025, the disease was confirmed in Morgan County.

Although corn is their only reproductive host, corn leafhoppers can feed on other grasses, such as gamagrass and Johnsongrass, and occasionally on alfalfa, triticale, or winter annual weeds, though these are not confirmed as feeding hosts, Valmorbida notes.

The 1/8-inch pale yellow insects are identifiable by two dark spots with white halos between their eyes. They feed on corn phloem, producing a honeydew-like substance that can encourage black sooty mold. Adults are commonly found in the corn whorl or on leaf undersides.

Corn stunt symptoms develop one to eight weeks after infection and vary based on growth stage, inoculum level, corn variety, and environmental conditions. Typical signs include yellow streaks at leaf bases, yellowing or reddening leaf tips, shortened internodes, small ears, poor grain filling, and in severe cases, wilting or plant death.

Management is challenging because damage is irreversible once plants are infected. “The earlier the infection, the greater the damage,” Valmorbida says. He recommends frequent scouting, using yellow sticky traps, considering insecticidal seed treatments for control up to the V3 stage, applying foliar insecticides before R1, and planting early to reduce risk.

For detailed guidance, see MU Extension’s publication Biology and Management of Corn Leafhopper.

Photo Credit: gettyimages-awakr10