Pest Management Science (2012) 68, 245-253

Alvaro Fuentealba and Éric Bauce (2012)
Site factors and management influence short-term host resistance to spruce budworm, Choristoneura fumiferana (Clem.), in a species-specific manner
Pest Management Science 68 (2), 245-253
Abstract: BACKGROUND: This study examined the interactions between thinning and soil drainage classes on the resistance of balsam fir, Abies balsamea (L.) Mill, white spruce, Picea glauca (Moench) Voss, and black spruce, P. mariana (Mill.) BSP, to spruce budworm, Choristoneura fumiferana (Clem.), defoliation 1 year after treatment. To estimate host tree resistance, foliage production and larval foliage consumption were determined to generate an index of resistance quantifying the amount of residual foliage available for photosynthesis after insect defoliation.
RESULTS: Significant interactions on tree resistance and foliage chemistry were detected between thinning and soil drainage in balsam fir. Drainage class affected spruce budworm performance, foliar chemistry and balsam fir resistance to spruce budworm, whereas no effect was found in white spruce. Thinning had a significant effect on the foliar chemistry of balsam fir and white spruce, but no effect on black spruce.
CONCLUSION: Thinning reduced balsam fir resistance to spruce budworm defoliation. This response is due to increased defoliation linked to reduction in concentrations of certain monoterpenes, and a decrease in foliage production, except on hydric drainage, demonstrating the importance of drainage class to tree resistance. The results suggest that the use of Bacillus thuringiensis might be required when conducting stand thinning during spruce budworm outbreaks.
(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): Alvaro Fuentealba, Eric Bauce

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Choristoneura fumiferana	Spruce (Picea)
	Choristoneura fumiferana	Fir (Abies)