Austral Entomology (2018) 57, 1-8

Tuyet T.A. Luong, Myron P. Zalucki, Lynda E. Perkins and Sharon J. Downes (2018)
Feeding behaviour and survival of Bacillus thuringiensis-resistant and Bacillus thuringiensis-susceptible larvae of Helicoverpa armigera (Lepidoptera: Noctuidae) exposed to a diet with Bacillus thuringiensis toxin
Austral Entomology 57 (1), 1-8
Abstract: Although higher than expected numbers of surviving larvae of Helicoverpa spp. are reported in some Bollgard II cotton fields from time to time, there is no convincing evidence that field resistance has developed. A behavioural component, specifically the avoidance of the toxin, was considered to contribute to larvae surviving on Bacillus thuringiensis (Bt) toxin-expressing plants. Experiments were conducted with Bt-susceptible and Bt-resistant larvae of Helicoverpa armigera to investigate (1) how larval responses to food deprivation might lead to differences in survival and therefore how far neonates could move to find a suitable feeding site and (2) whether larvae that are physiologically susceptible vs. resistant behave differently when feeding on diet with Bt and without Bt toxins. Bt-susceptible neonates of H. armigera, which were significantly heavier, could survive without food for longer and recover better than Bt-resistant neonates. Although H. armigera neonates did not shift their behaviour with respect to Bt toxin on artificial diet before their first feeding event, the tendency of Bt-susceptible larvae to remain on non-Bt diet and move off Bt diet may allow them to survive in a Bt environment. This behaviour resulted in a higher percentage of survival in situations where a diet choice was offered.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: English)
Link to article at publishers website
Database assignments for author(s): Tuyet T.A. Luong, Myron P. Zalucki, Lynda E. Perkins, Sharon Downes

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)	Australia (South+SE)
Bacillus thuringiensis genes in crops (entomopathogen)	Helicoverpa armigera	Cotton (Gossypium)	Australia (South+SE)