title: Chronic exposure of the European corn borer (Lepidoptera: Crambidae) to Cry1Ab Bacillus thuringiensis toxin.
abstract: 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 Hübner (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.
authors.affiliation: Institut National de la Recherche Agronomique, Unité de Recherches de Lutte biologique, La Minière, Guyancourt, France.
authors.forename: J
authors.initials: J
authors.lastname: Chaufaux
authors.forename: M
authors.initials: M
authors.lastname: Seguin
authors.forename: J J
authors.initials: JJ
authors.lastname: Swanson
authors.forename: D
authors.initials: D
authors.lastname: Bourguet
authors.forename: B D
authors.initials: BD
authors.lastname: Siegfried
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000494:pharmacology*; D004731:Endotoxins / Q000494:pharmacology*; D005602:France; D006460:Hemolysin Proteins; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D009036:Moths / Q000187:drug effects*; D009329:Nebraska; D010572:Pest Control, Biological / Q000379:methods*
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis