Corn leafhopper advances in Nebraska

A corn leafhopper (Dalbulus maidis) has been confirmed in crops in southeastern Nebraska, United States. The pest, which transmits the pathogen that causes corn stunt, was first recorded in Kansas and Oklahoma in 2024. This information is from the University of Nebraska.

In 2024, two fields in Jefferson County and one in Burt County tested positive for stunt disease. The pathogen has not been detected in 2025, but the leafhopper was found again in Clay County on August 18.

The presence of the leafhopper has already been recorded in at least five Nebraska counties, including Adams, Clay, Burt, and Dawson. According to experts at the University of Nebraska, the economic risk is still low, as the pest's arrival has occurred late in the crop cycle.

Initial symptoms of the disease include chlorosis or reddening of leaf tips. When the infection occurs during the vegetative phase, plants may present short internodes, multiple ears, or excessive tillering. Diagnosis depends on laboratory tests, as symptoms can be confused with nutritional or abiotic stresses.

The corn leafhopper measures about 3 millimeters and has two dark spots between its eyes. It feeds on corn leaves, preferring shaded areas and the corn kernel. While feeding, the insect can acquire and transmit the corn stunt spiroplasma. The infection establishes itself in the growing tissues of the plant, and symptoms take about 30 days to appear.

Native to Central America, the leafhopper has expanded its range to southern Brazil and Argentina. In the United States, it has advanced as far as Texas and now occupies areas of the Midwest. Changes in climate and crop cultivation may have contributed to this shift.

Researchers recommend cultural practices as the most effective form of management. Early planting helps plants develop before the leafhopper's arrival. Eliminating volunteer corn and grasses around crops also reduces the insect's shelter and survival sites. Chemical control, for now, is not considered economically viable. Insecticide effectiveness has been low, and frequent applications would be necessary.

Seed treatments can protect corn up to the V3 stage. However, there is not yet enough data on leafhopper population dynamics in Nebraska to confirm the importance of this protection window.