In 2025, we detected corn leafhoppers, Dalbulus maidis (Hemiptera: Cicadellidae), in low numbers from July to September in some counties in Kentucky; however, high numbers were observed in a late-planted sweet corn field on a farm in southern Christian County, western Kentucky, during the last week of September (Figures 1 and 2). This field had been planted in mid-July.

Description and Distribution 

Corn leafhoppers are small insects (about 1/8 inch or 3 mm long), light tan to yellow in color, with two black dots surrounded by a whitish halo between the eyes. They are considered key pests of corn in Mexico, Central America, and Brazil; on occasion, they have also moved into southern Texas. In 2024, this insect migrated northward and was detected in many central and northern states, reaching as far as New York and southern Ontario, Canada. In Kentucky, it was first recorded in 2024 in a suction trap at the UK Research and Education Center (UK-REC) in Princeton. 

Potential Damages

The main concern with corn leafhoppers is the transmission of corn stunt. Corn stunt is caused by two bacterial pathogens, corn stunt Spiroplasma (CSS) and maize bushy stunt phytoplasma (MBSP), and one is a virus, maize rayado fino virus (MRFV). Visible symptoms of these diseases include dwarfism or stunted growth, leaf reddening, striping on leaves, and reduced yields. We collected corn leafhoppers and leaf samples for laboratory analysis to detect the presence of any of these pathogens. 

Large populations of corn leafhoppers can also cause significant direct damage by feeding on the plant. Heavy infestations may reduce yield, similar to other important sap-feeding pests such as aphids and scale insects. The farmer reported that in some plots he observed heavy honeydew accumulation on the plants, indicating high pest populations in the field.

Closing Comments

Monitoring data indicate that the corn leafhoppers detected in Kentucky are the result of migration from southern states. The first detections in western Kentucky in 2025 occurred in late July, so fields planted in June or July require special attention when monitoring for corn leafhoppers. To date, we have detected corn leafhoppers only in low numbers in older fields, so no major problems have been observed, and no cases of corn stunt have been confirmed in the state thus far. We will continue to keep farmers, crop consultants, and Extension Agents updated on monitoring corn leafhopper populations and the results from laboratory analyses for corn stunt pathogens.

More Information

• Kentucky Pest News: Corn Leafhopper Detected in Kentucky Corn in 2025
• Lagos-Kutz, D.M., et al. 2025. First Report of Corn Leafhopper (Hemiptera: Cicadellidae) in the USA Midwest Suction Trap Network. 2025. Insecta Mundi 1110: 1–10. Published: February 28, 2025.