Oecologia

, Volume 159, Issue 3, pp 627–635

Resource competition and shared natural enemies in experimental insect communities

Authors

  • Thomas S. Jones
    • NERC Centre for Population Biology and Division of BiologyImperial College London
    • Institute of Environmental SciencesUniversity of Zürich
  • H. Charles J. Godfray
    • NERC Centre for Population Biology and Division of BiologyImperial College London
    • Department of ZoologyUniversity of Oxford
    • NERC Centre for Population Biology and Division of BiologyImperial College London
Community Ecology - Original Paper

DOI: 10.1007/s00442-008-1247-z

Cite this article as:
Jones, T.S., Godfray, H.C.J. & van Veen, F.J.F. Oecologia (2009) 159: 627. doi:10.1007/s00442-008-1247-z

Abstract

Much theory has been developed to explore how competition for shared resources (exploitation competition) or the presence of shared natural enemies (apparent competition) might structure insect and other communities. It is harder to predict what happens when both processes operate simultaneously. We describe an experiment that attempted to explore how shared natural enemies and resource competition structured a simple experimental insect community. Replicated communities were assembled in population cages consisting of the aphid species Acyrthosiphon pisum and Megoura viciae either alone or competing for a resource, their shared host plant Vicia faba. Each combination was set up with and without the parasitoid Praon dorsale which attacked both species of aphid. Population dynamic data show that interspecific resource competition was the dominant process structuring the community. Though juvenile parasitoids could develop successfully inside hosts of both species, they failed to suppress either aphid below their carrying capacities and were unable to persist on one species. We suggest that intense resource competition may reduce the value of individual aphids as hosts for parasitoids such that their population growth rate is less than zero and discuss whether this phenomenon occurs in natural and agricultural communities.

Keywords

AphidCommunity structureFood webIndirect interactionsMicrocosm

Copyright information

© Springer-Verlag 2008