Agricultural and Forest Entomology (2004) 6, 105-109

Peter Dalin, Christer Björkman and Karin Eklund (2004)
Leaf beetle grazing does not induce willow trichome defence in the coppicing willow Salix viminalis
Agricultural and Forest Entomology 6 (2), 105-109
Abstract: 1. Willows are frequently attacked and defoliated by adult leaf beetles (Phratora vulgatissima L.) early in the season and the plants are then attacked again when new larvae emerge. The native willow Salix cinerea has previously been shown to respond to adult grazing by producing new leaves with an increased trichome density. Subsequent larval feeding was reduced on new leaves. This type of induced plant response may reduce insect damage and could potentially be utilized for plant protection in agricultural systems.
2. Here, we investigated if the willow species most commonly used for biomass production in short rotation coppice, Salix viminalis, also responds to adult beetle grazing by increasing trichome density. Larval performance and feeding behaviour on plants previously exposed to adult beetles was compared with that on undefoliated control plants in a greenhouse.
3. We found an overall decrease in trichome density within all the plants (i.e. trichome density was lower on new leaves compared to that for older basal leaves on S. viminalis). However, leaves of beetle defoliated plants had a higher trichome density compared to control plants. Larval growth and feeding was not affected by this difference between treatments. Larvae appeared to remove trichomes when feeding on S. viminalis, a behaviour that might explain the lack of difference between treatments.
(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): Christer Björkman

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.
	Phratora vulgatissima	Willow (Salix)	Sweden