Herbivore-induced plant volatiles mediate host selection by a root herbivore

Authors

  • Christelle A. M. Robert,

    1. Laboratory for Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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    • These authors contributed equally to this work.

  • Matthias Erb,

    1. Laboratory for Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
    2. Root–Herbivore Interactions Group, Max Planck Institute for Chemical Ecology, Beutenberg Campus, Hans-Knöll-Str. 8, 07745 Jena, Germany
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    • These authors contributed equally to this work.

  • Marianne Duployer,

    1. Laboratory for Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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  • Claudia Zwahlen,

    1. Laboratory for Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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  • Gwladys R. Doyen,

    1. Laboratory for Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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  • Ted C. J. Turlings

    1. Laboratory for Fundamental and Applied Research in Chemical Ecology (FARCE), University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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Author for correspondence:
Ted C. J. Turlings
Tel: +41 32 71 83158
Email: ted.turlings@unine.ch

Summary

  • In response to herbivore attack, plants mobilize chemical defenses and release distinct bouquets of volatiles. Aboveground herbivores are known to use changes in leaf volatile patterns to make foraging decisions, but it remains unclear whether belowground herbivores also use volatiles to select suitable host plants.
  • We therefore investigated how above- and belowground infestation affects the performance of the root feeder Diabrotica virgifera virgifera, and whether the larvae of this specialized beetle are able to use volatile cues to assess from a distance whether a potential host plant is already under herbivore attack.
  • Diabrotica virgifera larvae showed stronger growth on roots previously attacked by conspecific larvae, but performed more poorly on roots of plants whose leaves had been attacked by larvae of the moth Spodoptera littoralis. Fittingly, D. virgifera larvae were attracted to plants that were infested with conspecifics, whereas they avoided plants that were attacked by S. littoralis. We identified (E)-β-caryophyllene, which is induced by D. virgifera, and ethylene, which is suppressed by S. littoralis, as two signals used by D. virgifera larvae to locate plants that are most suitable for their development.
  • Our study demonstrates that soil-dwelling insects can use herbivore-induced changes in root volatile emissions to identify suitable host plants.

Ancillary