title: Greenhouse-selected resistance to Cry3Bb1-producing corn in three western corn rootworm populations.
abstract: Transgenic corn producing the Bacillus thuringiensis (Bt) toxin Cry3Bb1 has been useful for controlling western corn rootworm, Diabrotica virgifera virgifera LeConte, one of the most economically important crop pests in the United States. However, rapid evolution of resistance by this beetle to Bt corn producing Cry3Bb1 has been reported previously from the laboratory, greenhouse, and field. Here we selected in the greenhouse for resistance to Cry3Bb1 corn in three colonies of WCR derived from Kansas, Minnesota, and Wisconsin, respectively. Three generations of rearing on Cry3Bb1 corn significantly increased larval survival on Cry3Bb1 corn, resulting in similar survival in the greenhouse for selected colonies on Cry3Bb1 corn and isoline corn that does not produce Bt toxin. After four to seven generations of rearing on Cry3Bb1 corn, survival in the field on Cry3Bb1 corn relative to isoline corn more than doubled for selected colonies (72%) compared with control colonies (33%). For both selected and control colonies, survival in the field was significantly lower on Cry3Bb1 corn than on isoline corn. On isoline corn, most fitness components were similar for selected colonies and control colonies. However, fecundity was significantly lower for selected colonies than control colonies, indicating a fitness cost associated with resistance. The rapid evolution of resistance by western corn rootworm to Bt corn reported here and previously underlines the importance of effective resistance management for this pest.
authors.affiliation: Plant-Insect Interactions, The Boyce Thompson Institute for Plant Research, Ithaca, New York, United States of America. lnm2m9@mail.missouri.edu
authors.forename: Lisa N
authors.initials: LN
authors.lastname: Meihls
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Higdon
authors.forename: Mark R
authors.initials: MR
authors.lastname: Ellersieck
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Tabashnik
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Hibbard
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000187:drug effects* / Q000502:physiology*; D004351:Drug Resistance; D004731:Endotoxins / Q000096:biosynthesis* / Q000235:genetics / Q000633:toxicity*; D004780:Environment, Controlled; D005260:Female; D008297:Male; D010572:Pest Control, Biological; D018517:Plant Roots / Q000254:growth & development; D030821:Plants, Genetically Modified; D003313:Zea mays / Q000235:genetics / Q000378:metabolism*
chemical_list: C507666:Cry3Bbl endotoxin, Bacillus thuringiensis; D004731:Endotoxins