By Scout Nelson
Kansas corn growers are being encouraged to intensify scouting efforts after the corn leafhopper (Dalbulus maidis), the insect that spreads corn stunt disease, was confirmed in central Kansas. Although the pest has been detected, testing has not found corn stunt spiroplasma (CSS, Spiroplasma kunkelii) in any of the collected insects.
The early arrival of corn leafhoppers this season has raised concerns about potential yield losses, especially in late-planted and double-cropped corn. Because disease symptoms can take up to 40 days to appear, regular field monitoring remains important throughout key growth stages.
Insecticides may help suppress corn leafhopper populations, but studies have shown that broad-spectrum products provide only limited control. Researchers found that some insecticides offered short-term suppression of nymphs, though repeated migrations of adult leafhoppers can reduce treatment effectiveness.
Growers should also be cautious when using products containing lambda-cyhalothrin, as they may increase the risk of spider mite infestations. In addition, once plants become infected, insecticide or fungicide applications cannot reverse the disease.
Corn leafhoppers are small, light tan to yellowish-white insects measuring about 1/8 inch long. A key identifying feature is the presence of two dark spots between the eyes and antennae, while nymphs are wingless and may vary in color.
Farmers should note that other leafhopper species, including the aster leafhopper, can be mistaken for corn leafhoppers. Proper identification is essential for accurate monitoring and management decisions.
To support statewide tracking efforts, K-State is offering free testing for both corn leafhopper identification and corn stunt disease. Producers are encouraged to submit insect and plant samples to help researchers monitor the spread of the pest and disease across Kansas.
Additional information on scouting, identification, and disease management is available at https://kscorn.com/corndisease/.
Photo Credit: gettyimages-oticki
Categories: Kansas, Crops, Corn