title: The effects of chrysomelid beetle grazing and plant competition on the growth of Rumex obtusifolius.
abstract: The interaction between grazing by Gastrophysa viridula and interspecific plant competition was investigated for Rumex obtusifolius growing in the field. During an eight-month growing season non-competing R. obtusifolius grew larger than competing plants although herbivore loads (beetle productivity per unit leaf area) were similar for competing and non-competing plants. However, grazing significantly reduced the growth of R. obtusifolius only in competing plants thus demonstrating a synergism between plant competition and invertebrate herbivory. The relevance of these findings for the distribution of plant species is discussed.
authors.affiliation: Department of Biological Sciences, University of Lancaster, Bailrigg, LA1 4YQ, Lancaster, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Cottam
authors.affiliation: Department of Biological Sciences, University of Lancaster, Bailrigg, LA1 4YQ, Lancaster, UK.
authors.forename: J B
authors.initials: JB
authors.lastname: Whittaker
authors.affiliation: Department of Biological Sciences, University of Lancaster, Bailrigg, LA1 4YQ, Lancaster, UK.
authors.forename: A J C
authors.initials: AJ
authors.lastname: Malloch
keywords: Gastrophysa; Grazing; Growth; Plant competition; Rumex