By Blake Jackson
University of Missouri Extension specialists are encouraging corn growers across the state to closely monitor their fields for signs of corn leafhopper, a pest that poses a serious threat to crop yields.
First identified in Christian County in 2024, corn leafhopper was recently confirmed in Lawrence and Boone counties during the week of July 7, 2025, according to MU Extension state crops entomologist Ivair Valmorbida.
The Crop Protection Network reports that this pest has now been found in four U.S. states and is already widespread in regions like South America and Mexico.
Following the initial detection in Missouri, growers and agricultural professionals have been urged to stay vigilant. The small insect, pale yellow to greenish yellow in color, feeds on corn and its relatives.
More concerning, it transmits pathogens that cause corn stunt disease-a condition that can lead to short stalks, misshapen ears, and reduced grain quality.
“Corn stunt symptoms generally appear within 30 days of infection. By then, there is nothing farmers can do,” Valmorbida warns. This pest poses a dual threat: damaging plants through feeding and spreading disease-causing organisms.
Though corn leafhoppers do not survive Missouri winters, they can migrate from southern states. They are often mistaken for aster leafhoppers, making accurate identification critical. “Accurate insect identification is essential for effective pest management,” says Valmorbida.
Despite their tiny size-just 1/8 inch long-these insects can be detected by the shiny honeydew residue they leave on leaves, which can lead to black, sooty mold that inhibits photosynthesis. The pests typically hide in shaded areas, feeding on young corn plants’ whorls and the undersides of leaves.
Valmorbida suggests using sweep nets, yellow sticky cards, and careful visual inspections when scouting fields. Though no established economic threshold currently exists, prevention remains key.
His top recommendations include planting corn as early as possible to avoid peak insect activity, using insecticidal seed treatments for early-stage protection (up to V3), and applying foliar insecticides if infestations are noticed before reproductive growth stages.
Proactive scouting and early intervention are essential to limit potential damage and preserve crop health.
Photo Credit: gettyimages-dszc
Categories: Missouri, Crops, Corn