Arthropod-Plant Interactions (2014) 8, 361-371

Dorthea M. Grégoire, Dan T. Quiring, Lucie Royer and Éric Bauce (2014)
Relationship between an exotic phloem feeder and balsam fir (Abies balsamea L. (Mill.)) foliar chemistry: implications for two native defoliators
Arthropod-Plant Interactions 8 (4), 361-371
Abstract: The balsam woolly adelgid (Adelges piceae) is a gout-inducing hemipteran native to the silver fir forests of Europe. Introduced to eastern North America approximately 100 years ago, it is now found in most balsam fir forests in Atlantic Canada. When A. piceae feed, they trigger a reaction in the host branch that alters both xylem and phloem morphology. We conducted a field survey to examine the relationship between A. piceae gout density and balsam fir foliar chemistry and shoot growth in naturally unthinned and precommercially thinned stands. A. piceae gout density negatively affected branch growth and was related to changes in the chemistry of older, but not current-year foliage. Older foliage experienced decreases in camphene and bornyl acetate, while foliar concentrations of camphene, myrcene, phenolics, potassium and water differed between thinned and unthinned stands. Foliar chemistry was also influenced by interactions between thinning and A. piceae gout density in old foliage. This study suggests that changes in balsam fir associated with A. piceae gout density may force native defoliators that feed in highly gouted trees to adapt to diets of different chemical compositions and that thinning may alter these interactions.
(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): 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.
	Adelges piceae	Fir (Abies)	Canada (east)