Marschner Review

Plant and Soil

, Volume 358, Issue 1, pp 51-60

First online:

The importance of root-produced volatiles as foraging cues for entomopathogenic nematodes

  • Ted C. J. TurlingsAffiliated withFARCE Laboratory, Institute of Biology, University of Neuchâtel Email author 
  • , Ivan HiltpoldAffiliated withUniversity of Missouri
  • , Sergio RasmannAffiliated withInstitute of Evolution and Ecology, University of Lausanne

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access



Entomopathogenic nematodes (EPNs) are tiny parasitic worms that parasitize insects, in which they reproduce. Their foraging behavior has been subject to numerous studies, most of which have proposed that, at short distances, EPNs use chemicals that are emitted directly from the host as host location cues. Carbon dioxide (CO2) in particular has been implicated as an important cue. Recent evidence shows that at longer distances several EPNs take advantage of volatiles that are specifically emitted by roots in response to insect attack. Studies that have revealed these plant-mediated interactions among three trophic levels have been met with some disbelief.


This review aims to take away this skepticism by summarizing the evidence for a role of root volatiles as foraging cues for EPNs. To reinforce our argument, we conducted olfactometer assays in which we directly compared the attraction of an EPN species to CO2 and two typical inducible root volatiles.


The combination of the ubiquitous gas and a more specific root volatile was found to be considerably more attractive than one of the two alone. Hence, future studies on EPN foraging behavior should take into account that CO2 and plant volatiles may work in synergy as attractants for EPNs. Recent research efforts also reveal prospects of exploiting plant-produced signals to improve the biological control of insect pests in the rhizosphere.


Entomopathogenic nematodes Foraging behavior Root volatiles Carbon dioxide Belowground tritrophic interactions