2nd Place: Evaluation of larval movement and survival for western corn rootworm and European corn borer in blended refuges of short-stature corn

Short-stature corn may soon become commercially available to corn producers in the United States. There are several advantages of short-stature corn over its counterparts, which is expected to facilitate adoption of short-stature corn in the US Corn Belt. However, knowledge gaps exist concerning some interactions of insect pests with short-stature corn and the implications of these interactions for insect resistance management (IRM) approaches. Western corn rootworm, Diabrotica virgifera virgifera, and European corn borer, Ostrinia nubilalis, are important pests found in the US Corn Belt. To protect crops from these pests, transgenic corn producing insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) is frequently grown by farmers. To delay Bt resistance, IRM plans are used in conjunction with the cultivation of Bt crops, and one IRM approach involves planting blended refuges that contain a mixture of Bt and non-Bt plants. We studied larval pest movement and survival in blended refuges of short-stature corn and tall corn. Six arrays, in which the positions of Bt and non-Bt plants differed, were used for each type of corn. The central plant in each array received eggs of either western corn rootworm or European corn borer. After allowing time for larval development, plants in each array were sampled to measure pest abundance at the different positions, thus allowing us to assess patterns of larval movement. The findings of this study will help to improve IRM strategies for short-stature corn.