Larval movement and survival for western corn rootworm and European corn borer in blended refuges of short-stature corn

Short-stature corn is a newly developed variety that may soon be grown in some corn-producing regions of the United States. However, little is currently known about how insect pests interact with short-stature corn. Western corn rootworm, Diabrotica virgifera virgifera, and European corn borer, Ostrinia nubilalis, are important pests encountered by corn producers. To prevent yield losses from these pests, transgenic corn varieties that produce insecticidal toxins originating from the bacterium Bacillus thuringiensis (Bt) are widely planted. One strategy of insect resistance management (IRM) to delay pest resistance to Bt toxins involves planting blended refuges that contain a mixture of Bt and non-Bt plants. We studied larval pest movement in blended refuges of short-stature corn and tall corn. Six arrays were used for both short-stature corn and tall corn. Positions of Bt and non-Bt plants differed in each type of array. The central plant of an array received eggs of either western corn rootworm or European corn borer. Later, plants in each array were sampled and pest abundance was measured. The findings of this study will help to improve insect resistance management strategies for short-stature corn.