Journal of Economic Entomology (2011) 104, 1045-1054

Lisa N. Meihls, Matthew L. Higdon, Mark Ellersieck and Bruce E. Hibbard (2011)
Selection for resistance to mCry3A-expressing transgenic corn in western corn rootworm
Journal of Economic Entomology 104 (3), 1045-1054
Abstract: To investigate the development of resistance to mCry3A, a laboratory colony of the western corn rootworm, Diabrotica virgifera virgifera LeConte, was established from field survivors of mCry3A-expressing (MIR604) corn, Zea mays L. Feral adults emerging from MIR604 (selected) and isoline (control) field plots were collected and returned to the laboratory. Progeny of each colony was reared one generation on isoline corn and then crossed reciprocally with a nondiapausing colony. The resulting nondiapausing progeny were then reared on greenhouse corn in accordance with the wild type parent's origin (on MIR604 or isoline corn). After four, seven, and 10 total generations of selection, the resistance ratio of the selected colony was 0.5, 4.3, and 15.4 in terms of lethal concentration (LC)₅₀ values in toxicity assays, with the latter two LC₅₀ values being significant. After seven generations of selection in total, selected and control colonies were screened on MIR604 and isoline corn under field conditions. There was a significant colony × corn pedigree interaction in terms of plant damage. There was no significant difference in damage between MIR604 and isoline corn, whereas this difference was significant for the control colony. After 14 generations of selection, a seedling bioassay was performed. Again, there was a significant colony × corn pedigree interaction, this time in terms of the number of larvae recovered. There was no significant difference in the number of larvae recovered from MIR604 and isoline corn for the selected colony, whereas this difference was significant for the control colony, although larval size was greater on isoline corn for both colonies. Resistance has developed in western corn rootworm laboratory colonies to all Bt proteins currently registered for corn rootworm management, which emphasizes the importance of adhering to resistance management plans for maintaining product efficacy.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Bruce E. Hibbard

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Diabrotica virgifera	Maize/corn (Zea mays)	U.S.A. (mid N)
Bacillus thuringiensis genes in crops (entomopathogen)	Diabrotica virgifera	Maize/corn (Zea mays)	U.S.A. (mid N)
Bacillus thuringiensis Cry3A-toxin (entomopathogen)	Diabrotica virgifera	Maize/corn (Zea mays)