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

Christelle Aurélie Maud Robert, Matthias Erb, M. Duployer, Claudia Zwahlen, G. R. Doyen & Ted Turlings

Résumé 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 similar to virgifera larvae were attracted to plants that were infested with conspecifics, whereas they avoided plants that were attacked by S similar to littoralis. We identified (E)-beta-caryophyllene, which is induced by D similar to virgifera, and ethylene, which is suppressed by S similar to littoralis, as two signals used by D similar to 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.
Mots-clés diabrotica virgifera virgifera, herbivore-induced plant volatiles, host plant selection, optimal foraging, root herbivore, western corn-rootworm, below-ground herbivory, aggregation pheromone, larvae coleoptera, beetle coleoptera, background odor, essential oil, maize, chrysomelidae, insects
Citation Robert, C. A. M., Erb, M., Duployer, M., Zwahlen, C., Doyen, G. R., & Turlings, T. (2012). Herbivore-induced plant volatiles mediate host selection by a root herbivore. New Phytologist, 194(4), 1061-1069.
Type Article de périodique (Anglais)
Date de publication 2012
Nom du périodique New Phytologist
Volume 194
Numéro 4
Pages 1061-1069