Monday, December 10, 2007 - 8:17 AM

Examining the impacts of refuge structure in transgenic corn: How does refuge-in-a-bag compare to other options?

Alexzandra McKinnis, and Christian H. Krupke, Purdue University, Entomology, 901 West State St, West Lafayette, IN

Increasing acreage is being devoted to transgenic (or Bt) corn for the management of the western corn rootworm (Diabrotica virgifera virgifera LeConte). However, mandatory compliance with the 20% refuge requirement is difficult to enforce, creating the potential for deficiencies in the area of resistance management. We examined the effects of various refuge structures using both economic (root damage and yield) and biological (beetle emergence timing, sex ratio, and abundance) parameters to determine the relative benefits and disadvantages of each. Our experiment included seven treatments: 20% and 10% refuge planted as a block, 20% and 10% refuge planted in strips, 20% and 10% refuge in the form of a seed mix and a 100% refuge plot. The results will be discussed from the perspective of balancing current and future resistance management for Bt rootworm corn with the economic realities of production agriculture.

Species 1: Coleoptera Chrysomelidae Diabrotica virgifera virgifera (western corn rootworm)