Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2004
Publication Date: N/A
Technical Abstract: The western corn rootworm is a serious pest of maize in the United States, Canada, and parts of Europe. Current methods for controlling rootworm include crop rotation, insecticides and transgenic maize. While native resistance has been difficult to implement in modern maize hybrids, progress has been made. Damage levels are significantly lower in resistant varieties than for susceptible lines but greater than for insecticides or transgenic maize. We examined whether current levels of native resistance could provide acceptable levels of rootworm control when coupled with an insecticidal seed treatment. The experiment was a randomized split-plot design (five replications) conducted at two sites in Missouri (one with a natural rootworm population, the other manually infested). We evaluated a native resistant population of maize which contained a composite of resistance sources at cycle 0 and after 5 cycles of recurrent selection for reduced larval feeding damage, a modern hybrid with transgenic resistance and its susceptible near-isoline. Each maize line was protected with a traditional granular insecticide, a rootworm seed treatment rate, a secondary seed treatment rate, or no insecticide. Data was collected on root damage ratings (0-3 scale) and adult emergence. If maize conferring native resistance to rootworm has a synergistic or additive effect with seed treatments, then the combination may have utility as an alternative to conventional and/or transgenic control tactics. Data will be discussed in terms of a management alternative and in terms of refuge requirements and resistance management for transgenic maize.