Entomology, Department of
Chronic Exposure of the European Corn Borer (Lepidoptera: Crambidae) to Cry1Ab Bacillus thuringiensis Toxin
Date of this Version
Transgenic corn expressing the insecticidal toxin from Bacillus thuringiensis Berliner is gaining support as an effective control technology for use against lepidopteran pests, particularly European corn borer, Ostrinia nubilalis Hubner (Lepidoptera: Crambidae). However, there is concern that widespread adoption of transgenic plants will rapidly lead to B. thuringiensis toxin resistance. Thus, long-term selection of O. nubilalis populations with the Cry1Ab B. thuringiensis toxin has been undertaken in several laboratories in the United States and in Europe. We present results from two independent selection experiments performed in laboratories at the University of Nebraska and at the Institut National de la Recherche Agronomique in France. Although the protocols and methods used by the two laboratories were different, the results were comparable. The highest level of resistance occurred at generation 7 (14-fold), generation 9 (13-fold), and generation 9 (32-fold) for three different strains. For each strain, the level of resistance fluctuated from generation to generation, although there were consistently significant decreases in toxin susceptibility across generations for all selected strains. These results suggest that low levels of resistance are common among widely distributed O. nubilalis populations.
Published in Journal of Economic Entomology Volume 94, Issue 6 (December 2001) pp. 1564–1570.This article is the copyright property of the Entomological Society of America and may not be used for any commercial or other private purpose without specific written permission of the Entomological Society of America. Used by permission.