Interactions between plant pathogens and arthropods have been predominantly studied through the prism of herbivorous arthropods. Currently, little is known about the effect of plant pathogens on the third trophic level. This question is particularly interesting in cases where pathogens manipulate host phenotype to increase vector attraction and presumably increase their own proliferation. Indeed, a predator or a parasitoid of a vector may take advantage of this manipulated phenotype to increase its foraging performance. We explored the case of a bacterial pathogen, Candidatus Liberibacter asiaticus (Las), which modifies the odors released by its host plant (citrus trees) to attract its vector, the psyllid Diaphorina citri. We found that the specialist parasitoid of D. citri, Tamarixia radiata, was attracted more toward Las-infected than uninfected plants. We demonstrated that this attractiveness was due to the release of methyl salicylate. Parasitization of D. citri nymphs on Las-infected plants was higher than on uninfected controls. Also, parasitization was higher on uninfected plants baited with methyl salicylate than on non-baited controls. This is the first report of a parasitoid “eavesdropping” on a plant volatile induced by bacterial pathogen infection, which also increases effectiveness of host seeking behavior of its herbivorous vector.
Keywords: plant pathogens, parasitoids, tri-trophic interactions, semiochemicals, huanglongbing
Citation: Martini X, Pelz-Stelinski KS and Stelinski LL (2014) Plant pathogen-induced volatiles attract parasitoids to increase parasitism of an insect vector. Front. Ecol. Evol. 2:8. doi: 10.3389/fevo.2014.00008
Received: 30 January 2014; Paper pending published: 10 March 2014;
Accepted: 18 March 2014; Published online: 29 May 2014.
Edited by:Juergen Gross, Julius Kühn-Institut, Germany
Copyright © 2014 Martini, Pelz-Stelinski and Stelinski. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Lukasz L. Stelinski, Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA e-mail: email@example.com