Journal of Pest Science (2007) 80, 139-143

J. Gross, N. E. Fatouros, S. Neuvonen, M. Hilker (2007)
The role of competitors for Chrysomela lapponica, a north Eurasian willow pest, in pioneering a new host plant
Journal of Pest Science 80 (3), 139-143
Abstract: The Palaearctic leaf beetle Chrysomela lapponica usually feeds upon willows in the northern region of its occurrence. However, in Central Europe, some populations are known that have specialised on birch. In this study, we investigated the significance of other herbivores occurring together on the same host plants as possible exploitative competitors of C. lapponica. Two populations were studied: a population from Finland specialised on the willow Salix borealis, and a population from the Czech Republic, specialised on the birch Betula pubescens. Abundances of folivorous and suctivorous insects on both host plants were recorded at both population sites. The willow leaf beetle Phratora vitellinae was the most abundant herbivorous insect at both study sites on willow. A field study was conducted to examine the effects of P. vitellinae on the performance of C. lapponica. The presence of P. vitellinae larvae on the same twig upon which C. lapponica larvae were feeding did not affect increase of body weight in C. lapponica larvae. Thus, the high resource availability of both willows and birches suggest that interspecific competition is unlikely to be a selection factor driving the evolution of host shift in C. lapponica.
(The abstract has been supplied by the author or ISPI and is excluded from the Creative Commons licence.)
Database assignments for author(s): Jürgen Gross, Monika Hilker

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Chrysomela lapponica	Willow (Salix)	Finland
	Phratora vitellinae	Willow (Salix)	Finland
	Chrysomela lapponica	Birch (Betula)	Czech Republic
	Phratora vitellinae	Birch (Betula)	Czech Republic