Translator Disclaimer
1 February 2015 Emergence and Abundance of Western Corn Rootworm (Coleoptera: Chrysomelidae) in Bt Cornfields With Structured and Seed Blend Refuges
Author Affiliations +

To slow evolution of western corn rootworm (Diabrotica virgifera virgifera LeConte) resistance to Bt (Bacillus thuringiensis Berliner) corn hybrids, non-Bt “refuges” must be planted within or adjacent to Bt cornfields, allowing susceptible insects to develop without exposure to Bt toxins. Btsusceptible adults from refuges are expected to find and mate with resistant adults that have emerged from Bt corn, reducing the likelihood that Bt-resistant offspring are produced. The spatial and temporal distribution of adults in four refuge treatments (20, 5, and 0% structured refuges and 5% seed blend) and adjacent soybean fields was compared from 2010 to 2012. Adult emergence (adults/trap/day) from refuge corn in structured refuge treatments was greater than that from Bt corn, except during the post-pollination period of corn phenology when emergence from refuge and Bt plants was often the same. Abundance of free-moving adults was greatest in and near refuge rows in structured refuge treatments during vegetative and pollination periods. By post-pollination, adult abundance became evenly distributed. In contrast, adult abundance in 5% seed blends and 0% refuges was evenly distributed, or nearly so, across plots throughout the season. The persistent concentration of adults in refuge rows suggests that structured refuge configurations may not facilitate the expected mixing of adults from refuge and Bt corn. Seed blends produce uniform distributions of adults across the field that may facilitate mating between Bt and refuge adults and ultimately delay the evolution of Bt resistance.

© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email:
Sarah A. Hughson and Joseph L. Spencer "Emergence and Abundance of Western Corn Rootworm (Coleoptera: Chrysomelidae) in Bt Cornfields With Structured and Seed Blend Refuges," Journal of Economic Entomology 108(1), 114-125, (1 February 2015).
Received: 7 March 2014; Accepted: 25 September 2014; Published: 1 February 2015

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top