Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Density-mediated and trait-mediated indirect interactions between species may have important roles in structuring ecological communities. Here we dissect their contributions to community stability in a model herbivore-natural enemy interaction consisting of two aphid species (Acyrthosiphon pisum and Megoura viciae) and a specialist parasitoid (Aphidius ervi) that attacks only one of the aphids (A. pisum). In replicated cage experiments, we found that the two aphid species alone were unable to coexist, with A. pisum competitively excluding M. viciae. We also found that the simple host-parasitoid interaction between A. pisum and the parasitoid was unstable. However, the three-species community persisted for at least 50 weeks. We constructed a series of models to explain the stability of the full community and conclude that it is due to a combination of density-mediated and trait-mediated indirect interactions. Parasitoid attack on the susceptible host reduces the interspecific competition experienced by the non-host (a density-mediated effect), and the presence of the non-host reduces the searching efficiency of the parasitoid (a trait-mediated effect). © 2005 by the Ecological Society of America.

Original publication

DOI

10.1890/04-1590

Type

Journal article

Journal

Ecology

Publication Date

01/12/2005

Volume

86

Pages

3182 - 3189