Pest Management Science (2008) 64, 813-819

Ali H. Sayyed, Graham Moores, Neil Crickmore and Denis J. Wright (2008)
Cross-resistance between a Bacillus thuringiensis Cry toxin and non-Bt insecticides in the diamondback moth
Pest Management Science 64 (8), 813-819
Abstract: BACKGROUND: Bacillus thuringiensis Berliner (Bt) crystal (Cry) toxins are expressed in various transgenic crops and are also used as sprays in integrated pest management and organic agricultural systems. The diamondback moth (Plutella xylostella L.) is a major worldwide pest of crucifer crops and one that has readily acquired field resistance to a broad range of insecticides.
RESULTS: Selection of a subpopulation of the P. xylostella SERD4 population with the pyrethroid deltamethrin increased resistance to both deltamethrin and Cry1Ac relative to an unselected subpopulation. Selection of a second subpopulation with the Bt toxin Cry1Ac also increased resistance to both Cry1Ac and deltamethrin. A complementation test between the Cry1Ac-selected and deltamethrin-selected subpopulations suggested the presence of a common genetic locus or loci that control resistance to both insecticides. A piperonyl butoxide analogue with potent inhibitory activity against insect esterases significantly increased the toxicity of Cry1Ac and deltamethrin against the respective resistant subpopulations, but showed no such synergism with the unselected subpopulation of SERD4.
Selection of one resistance phenotype resulted in the simultaneous selection of the other. This phenomenon could be due to a single mechanism acting against both classes of insecticide or to genetically linked, but separate, mechanisms.
(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): Ali H. Sayyed, Graham D. Moores, Denis J. Wright, Neil Crickmore

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
pesticide resistance of pest
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.
	Plutella xylostella
Bacillus thuringiensis Cry1A-toxin (entomopathogen)	Plutella xylostella