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Baseline Susceptibility Of Western Corn Rootworm (Coleoptera: Crysomelidae) To Cry3bb1 Bacillus Thuringiensis Toxin, Blair D. Siegfried, Ty T. Vaughn, Terrence A. Spencer

Department of Entomology: Faculty Publications

Susceptibility to Cry3Bb1 toxin from Bacillus thuringiensis (Bt) was determined for western corn rootworm, Diabrotica virgifera virgifera LeConte, neonates from both laboratory and field populations collected from across the Corn Belt. Rootworm larvae were exposed to artificial diet treated with increasing Cry3Bb1 concentrations, and mortality and growth inhibition were evaluated after 4Ð7 d. The range of variation in Bt susceptibility indicated by growth inhibition was similar to that indicated by mortality. Although interpopulation variation in susceptibility was observed, the magnitude of the differences was comparable with the variability observed between generations of the same population. In general, the toxin was …