This article was written by Angie Peltier and Bruce Potter (UMN Extension) and Eric Burkness and Bill Hutchison (UMN Dept of Entomology). Purpose of Study European corn borer (ECB) larvae tunnel into stalks and ear shanks ( Figure 1 ). Feeding affects the transfer of water and nutrients within the plant and can directly affect yield by reducing kernel weight and number. ECB feeding can indirectly affect yield when tunnels cause stalk breakage, ear drop, or allow the entry of stalk rot and ear mold fungi. Figure 1. European corn borer ( Ostrinia nubilalis ). Clemson University, USDA Cooperative Extension Slide Series, Bugwood.org. ECB and Bt corn. More than 25 years ago scientists found a way to transfer a gene from a soil-borne bacterium called Bacillus thuringiensis (Bt) into the corn genome. Bt corn was approved for commercial use in 1996. Within the corn plant tissues, this gene produces a protein toxic to corn borer larvae. When ingested by larvae, the protein breaks do