Evaluating density-dependent mortality of larval western corn rootworm in Bt and non-Bt corn

Western corn rootworm (Diabrotica virgifera virgifera) is a major pest of corn in the US. Larval density-dependent mortality can confound mortality estimates of Bt traits and soil-applied insecticides used to manage western corn rootworm. Although little work has been done to study density-dependent mortality of western corn rootworm larvae in Bt corn, there are some reports that suggest it does occur. Previous studies have shown the importance of including density-dependent mortality factors in management plans. This study evaluates the effect of larval density-dependent mortality of western corn rootworm in Bt and non-Bt corn using artificial infestation at six egg densities ranging from 25 to 800 eggs per 30 cm of row. Understanding these interactions will increase our knowledge of western corn rootworm in Bt corn and improve management of this pest.