Abstract

We investigated host race formation in Galerucella tenella. a leaf beetle which feeds preferentially on meadowsweet (Rosaceae) in its natural habitats. but has become an important pest on strawberry (Rosaceae) in agricultural areas. Beetles from two isolated sites (Skeppsvik in Sweden and Solf in Finland) were compared with respect to preference and performance. At Skeppsvik the beetles were found feeding on meadowsweet. while at Solf large populations only develop in strawberry plantations, despite the presence of meadowsweet.In reciprocal field transplantations and laboratory bioassays. beetles from both sites discriminated against their foreign host, using their natal plant to a significantly higher degree for both egg laying and feeding. but with one interesting exception, namely that beetles from Solf increased their use of and even preferred meadowsweet for feeding in the laboratory. This increased use of meadowsweet by adult Solf beetles in the laboratory (without conspecific competitors) may be attributed to a density-dependent strategy, whereby mothers avoid pre-emptying the nutritional resources of the plants that will host their offspring in cases where no competitors are present.Larval fitness did not differ significantly between host plants, although larval Survival of Solf beetles was halved when reared on their non-natal host plant (meadowsweet). Although beetles from both sites preferred to oviposit on their local host Plant. Our results provide little evidence that this presumed adaptation has to do with the nutritional quality of the plants involved. Instead. we suggest that other factors associated with the plants, such Lis enemy-free space and resistance to drought may be more important selective agents, shaping host preference in the field. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

Keywords

speciation; Galerucella tenella; Filipendula ulmaria; Fragaria x ananassa; Skeppsvik; adaptation; selection; herbivore; chrysomelidae; herbivory

Published in

Basic and Applied Ecology
2008, Volume: 9, number: 5, pages: 560-567
Publisher: ELSEVIER GMBH, URBAN & FISCHER VERLAG

SLU Authors

• Axelsson, Petter

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Agricultural Science


Publication identifier

DOI: https://doi.org/10.1016/j.baae.2007.10.007

Permanent link to this page (URI)

https://res.slu.se/id/publ/18510