Translator Disclaimer
1 April 2009 Limited Survival of a Cry2Ab-Resistant Strain of Helicoverpa armigera (Lepidoptera: Noctuidae) on Bollgard II
Author Affiliations +
Abstract

Bollgard II cotton (which expresses two Bt insecticidal genes cry1Ac/cry2Ab) and conventional cotton, grown in the laboratory or field and sampled at different stages, was exposed to Helicoverpa armigera (Hübner) larvae of three genotypes: homozygous for resistance to Cry2Ab; homozygous for susceptibility to Cry2Ab, and heterozygous for resistance. Survival of all genotypes was limited on Bollgard II but increased as plants aged. This was particularly the case for homozygous resistant individuals, with 8.5% of this genotype surviving to pupation on mature cotton. The increasing survival is assumed to be caused by the decline in the titer of Cry1Ac toxin after flowering in Bollgard II because Cry2Ab homozygous resistant larvae can tolerate high levels of Cry2Ab toxin. Larvae heterozygous for resistance performed no better on Bollgard II than homozygous susceptible larvae. Survivors on Bollgard II grew more slowly and produced smaller pupae that yielded adults with reduced longevity and fecundity. When reared on conventional cotton, all genotypes generally performed equally, indicating an absence of fitness costs associated with Cry2Ab resistance under the conditions examined.

R. J. Mahon and K. M. Olsen "Limited Survival of a Cry2Ab-Resistant Strain of Helicoverpa armigera (Lepidoptera: Noctuidae) on Bollgard II," Journal of Economic Entomology 102(2), 708-716, (1 April 2009). https://doi.org/10.1603/029.102.0232
Received: 28 July 2008; Accepted: 1 October 2008; Published: 1 April 2009
JOURNAL ARTICLE
9 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top