Cross-kingdom interactions matter: fungal-mediated interactions structure an insect community on oak

Authors

  • Ayco J. M. Tack,

    Corresponding author
    1. Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), FI-00014 University of Helsinki, Helsinki, Finland
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  • Sofia Gripenberg,

    1. Metapopulation Research Group, Department of Biosciences, University of Helsinki, PO Box 65 (Viikinkaari 1), FI-00014 University of Helsinki, Helsinki, Finland
    2. Section of Biodiversity and Environmental Research, Department of Biology, University of Turku, Turku FI-20014, Finland
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  • Tomas Roslin

    1. Spatial Foodweb Ecology Group, Department of Agricultural Sciences, PO Box 27 (Latokartanonkaari 5), FI-00014 University of Helsinki, Helsinki, Finland
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E-mail: ayco.tack@helsinki.fi

Abstract

Ecology Letters (2012)

Abstract

Although phytophagous insects and plant pathogens frequently share the same host plant, interactions among such phylogenetically distant taxa have received limited attention. Here, we place pathogens and insects in the context of a multitrophic-level community. Focusing on the invasive powdery mildew Erysiphe alphitoides and the insect community on oak (Quercus robur), we demonstrate that mildew–insect interactions may be mediated by both the host plant and by natural enemies, and that the trait-specific outcome of individual interactions can range from negative to positive. Moreover, mildew affects resource selection by insects, thereby modifying the distribution of a specialist herbivore at two spatial scales (within and among trees). Finally, a long-term survey suggests that species-specific responses to mildew scale up to generate landscape-level variation in the insect community structure. Overall, our results show that frequently overlooked cross-kingdom interactions may play a major role in structuring terrestrial plant-based communities.

Ancillary