Journal of Economic Entomology (2006) 99, 893-898

Kongming Wu, Yuyuan Guo and Graham Head (2006)
Resistance monitoring of Helicoverpa armigera (Lepidoptera: Noctuidae) to Bt insecticidal protein during 2001-2004 in China
Journal of Economic Entomology 99 (3), 893-898
Abstract: Susceptibility of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) field populations to the Cry1Ac toxin of Bacillus thuringiensis Berliner (Bt) were monitored from 1997 to 2004 in China. During 2001-2004, 53 strains from the Bt cotton planting region were sampled. The range of concentration producing 50% inhibition of larval development to third instar (IC₅₀) values among different populations in 2001, 2002, 2003, and 2004 was 0.014-0.046, 0.010-0.062, 0.005-0.062, and 0.005-0.035 μg/ml, respectively. Diagnostic concentration studies (IC₉₉) showed that the percentage of individuals reaching third instar ranged from 0 to 9.09%, with only four of the 53 tested populations showing values above 0%. Considering these data, it was determined that the susceptibility to Cry1Ac of the field populations sampled was not different from the baseline in 1997, and no movement toward resistance among H. armigera populations was apparent.
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Link to article at publishers website
Database assignments for author(s): Kong Ming Wu, Graham Head, Yu Yuan Guo

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.
	Helicoverpa armigera	Cotton (Gossypium)	China (NE)
Bacillus thuringiensis genes in crops (entomopathogen)	Helicoverpa armigera	Cotton (Gossypium)	China (NE)
Bacillus thuringiensis Cry1A-toxin (entomopathogen)	Helicoverpa armigera	Cotton (Gossypium)	China (NE)