Corn leafhopper activity is rising fast, with recent detections in Missouri, Iowa, Illinois, and Indiana. While small in size, this pest can cause serious economic losses by spreading corn stunt disease. As summer progresses and young corn enters critical growth stages, now is the time to scout your crops and stay ahead of potential problems.
Risk of Corn Stunt Disease
Corn leafhoppers do more than feed on crops—they spread the bacterium behind corn stunt disease. Infected plants may develop red or purple leaf edges, distorted growth, and stunted height. The earlier the infection, the greater the yield loss. And once it takes hold, the damage is irreversible.
Scouting Guidelines
Weekly scouting is essential, especially in fields that were planted early or are experiencing stress from heat or drought. Focus on field edges first, where leafhoppers often appear. They prefer warm, protected areas and tend to cluster on the undersides of leaves. Use sweep nets or visual inspections to monitor populations.
Young corn is especially vulnerable, and signs of the pest often show up before symptoms of disease appear. Fields with a previous history of corn leafhopper activity should receive extra attention.
When to Act
Insecticide treatment may be needed if pest levels rise to threshold levels. However, decisions should be based on several factors, not just insect counts. Consider hybrid susceptibility, overall crop health, and weather conditions. Some corn hybrids show better tolerance to corn stunt, reducing the need for aggressive control.
Keep in mind that insecticides are most effective when applied before leafhoppers spread the disease, so early scouting improves the odds of success.
Limited Window to Prevent Damage
There’s no cure once corn stunt takes hold. That’s why it’s important to act early and intercept the vector before it moves deeper into the field. Once established, leafhopper populations can be hard to manage, and infected plants will continue to serve as a source of disease. Prevention through scouting and timely treatment is your best defense.
Get the Tools and Support You Need
To stay prepared against corn leafhopper, make sure you’re equipped with the right tools and crop protection strategies. For support and product recommendations, contact your local John Deere dealer today.