The first transgenic corn hybrids expressing the Bacillus thuringiensis (Bt) Cry3Bb1 protein to control corn rootworm larvae were registered for commercial use in 2003. This study was conducted to investigate the effect of Cry3Bb1 protein in combination with a cucurbitacin bait on adult feeding and longevity of both organophosphate-resistant and susceptible western corn rootworms, Diabrotica virgifera virgifera LeConte. In choice and no-choice tests, repellency to the Bt protein was quantified by comparing beetle consumption of cellulose disks treated with three concentrations of Bt in combination with Invite ECTM as the feeding stimulant to disks treated with Invite alone. A lethal-time assay was also conducted to examine survival of beetles exposed to Bt protein in their diet. For this assay, individual beetles of similar age were confined in wells of 128-well bioassay trays containing 250 ml of an agar-based diet treated with agar alone, Invite, or Invite+Bt protein at two concentrations. Results from these assays will be presented and discussed in relation to insect resistance management to transgenic corn.
Species 1: Coleoptera Chrysomelidae Diabrotica virgifera virgifera (western corn rootworm)
Keywords: behavior, survival
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