Adult Southwestern corn borers are a dull white to tan or yellowish in color. They have a wingspan of approximately 1¼-inches. The first generation of adult Southwestern corn borer moths flies in mid-to late May in Kentucky. The first generation larvae appear in early June. Late planted corn has the greatest potential for damage from the first generation. The second and third generations cause the greatest damage in Kentucky.

Southwestern corn borer moth.

During the late 1970's it was regarded as one of the most serious insect pests of corn, but after more than a ten-year period of not being reported in Kentucky, the southwestern corn borer has reappeared. Since 1992, the southwestern corn borer has spread across the western half of Kentucky and its distribution now extends to Hardin and Pulaski counties. Information on Southwestern corn borer biology, impact on corn, a comparison of the Southwestern and European corn borer and management can be found in EntFact-108 Southwestern Corn Borer.

To view the data that includes temperature and accumulated degree days you will need Microsoft Excel®.

University of Kentucky Research Center, Princeton,KY

University of Kentucky Spindletop Farm, Lexington, KY

Insect trap data are provided for educational purposes only. Weather data provided by the University of Kentucky Agricultural Weather Center and Kentucky Mesonet. Weather data if used for legal purposes must be certified by NCDC, National Climate Data Center.