Adult exposure to Bt toxin Cry1Ac reduces life span and reproduction of resistant and susceptible pink bollworm (Lepidoptera: Gelechiidae)

Ling Wang, Peng Wan, Shengbo Cong, Jintao Wang, Minsong Huang, Bruce E Tabashnik, Xianchun Li, Kongming Wu

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

Insecticidal proteins from Bacillus thuringiensis (Bt) are used widely in sprays and transgenic plants to control insect pests. Although much research has elucidated the effects of Bt toxins on larvae, relatively little is known about their effects on adults. Here, we evaluated the effects of exposing adults to Bt toxin Cry1Ac on the life span and reproduction of two strains of pink bollworm (Pectinophora gossypiella (Saunders)). In larval diet bioassays, the concentration of Cry1Ac killing 50% of larvae (LC50) was 640 times higher for the laboratory-selected resistant strain (AZP-R) than the susceptible strain (APHIS-S). In experiments with adults, the highest concentrations of Cry1Ac tested (160 and 640 μg Cry1Ac per ml of 5% honey water) reduced life span for both strains. Treatments with 10, 40, and 160 μg Cry1Ac per ml reduced the duration of the oviposition period as well as the number of eggs laid by both strains, but did not affect the percentage of pairs producing eggs, the duration of the preoviposition period, or the percentage of eggs hatching for either strain. Adult life span did not differ between strains at low to moderate concentrations of Cry1Ac, but it was significantly greater for the resistant strain than the susceptible strain at the two highest concentrations of Cry1Ac tested. The reduced susceptibility to high concentrations of Cry1Ac in adults of the AZP-R strain relative to the APHIS-S strain provides the first evidence of expression of resistance to a Bt toxin in adult Lepidoptera.

Original languageEnglish (US)
Pages (from-to)1357-1363
Number of pages7
JournalJournal of Economic Entomology
Volume109
Issue number3
DOIs
Publication statusPublished - Jun 1 2016

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Keywords

  • Adult life span
  • Bacillus thuringiensis
  • Pectinophora gossypiella
  • Reproduction

ASJC Scopus subject areas

  • Medicine(all)
  • Ecology
  • Insect Science

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