Journal of Chemical Ecology (2010) 36, 361-368

Jared G. Ali, Hans T. Alborn and Lukasz L. Stelinski (2010)
Subterranean herbivore-induced volatiles released by citrus roots upon feeding by Diaprepes abbreviatus recruit entomopathogenic nematodes
Journal of Chemical Ecology 36 (4), 361-368
Abstract: Herbivore-induced volatile emissions benefit plant hosts by recruiting natural enemies of herbivorous insects. Such tritrophic interactions have been examined thoroughly in the above-ground terrestrial environment. Recently, similar signals have also been described in the subterranean environment, which may be of equal importance for indirect plant defense. The larvae of the root weevil, Diaprepes abbreviates, are a serious pest of citrus. Infestations can be controlled by the use of entomopathogenic nematodes, yet the interactions between the plant, insect and nematode are poorly understood and remain unpredictable. In bioassays that used a root zone six-arm olfactometer, citrus roots ('Swingle citrumelo' rootstock) recruited significantly more entomopathogenic nematodes (Steinernema diaprepesi) when infested with root weevil larvae than non-infested roots. Infested plants were more attractive to nematodes than larvae alone. Roots damaged by weevil larvae attracted more nematodes than mechanically damaged roots and sand controls. By dynamic in situ collection and GC-MS analysis of volatiles from soil, we determined that four major terpene compounds were produced by infested plant roots that were not found in samples from non-infested roots or soil that contained only larvae. Solvent extracts of weevil-infested roots attracted more nematodes than extracts of non-infested roots in a two choice sand-column bioassay. These findings suggest that Swingle citrus roots release induced volatiles as an indirect defense in response to herbivore feeding, and that some of these induced volatiles function as attractants for entomopathogenic nematodes.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Lukasz Stelinski

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Diaprepes abbreviatus	Citrus (genus)
Steinernema diaprepesi (entomopathogen)	Diaprepes abbreviatus	Citrus (genus)