By Blake Jackson
Corn leafhoppers were identified in Missouri cornfields on June 16, 2026, and June 22, 2026, during routine scouting in Boone County. The findings are part of in-season monitoring led by University of Missouri Extension entomologist Ivair Valmorbida.
The insects were found on corn plants at the V5 growth stage, and no nymphs were observed. This suggests the adults likely migrated from the southern United States.
This detection marks the first occurrence in Missouri for 2026 and came about three weeks earlier than in 2025. Similar detections were also reported in Oklahoma earlier in June. Research from South America—where corn leafhoppers pose a greater threat—indicates that infections from corn stunt pathogens during early growth stages can significantly reduce yield. These pathogens were previously identified in Missouri during the 2024 and 2025 growing seasons.
Scouting efforts also identified aster leafhoppers, a native species not known to transmit corn stunt disease. Although both species are similar in size, corn leafhoppers can be recognized by two dark spots between the eyes surrounded by a white halo, along with a lack of additional facial markings.
Growers are encouraged to scout fields regularly, especially before the R1 growth stage. For more accurate monitoring, tools such as sweep nets or vacuums are recommended. During vegetative stages, inspections should focus on the whorl where insects tend to hide.
Managing corn leafhoppers is challenging and requires multiple strategies to reduce both insect populations and disease risk. While no economic threshold has been established, foliar insecticides may be considered when infestations are detected before R1, with careful attention to label instructions and the protection of beneficial insects.
For more information visit, https://extension.missouri.edu/publications/g7109
Photo Credit: ivair-valmorbida
Categories: Missouri, Crops, Corn