title: Subterranean, herbivore-induced plant volatile increases biological control activity of multiple beneficial nematode species in distinct habitats.
abstract: While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs). However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene) from citrus roots 9-12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus) compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis) again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests.
authors: Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, Lake Alfred, Florida, United States of America.
authors: Jared G
authors: JG
authors: Ali
authors: Hans T
authors: HT
authors: Alborn
authors: Raquel
authors: R
authors: Campos-Herrera
authors: Fatma
authors: F
authors: Kaplan
authors: Larry W
authors: LW
authors: Duncan
authors: Cesar
authors: C
authors: Rodriguez-Saona
authors: Albrecht M
authors: AM
authors: Koppenhöfer
authors: Lukasz L
authors: LL
authors: Stelinski
mesh_terms: D000818:Animals; D002957:Citrus / Q000378:metabolism / Q000469:parasitology*; D017753:Ecosystem; D005247:Feeding Behavior / Q000187:drug effects; D020387:Food Chain; D008401:Gas Chromatography-Mass Spectrometry; D060434:Herbivory; D006790:Host-Parasite Interactions; D006844:Hydrocarbons, Cyclic / Q000378:metabolism*; D007814:Larva / Q000502:physiology; D010572:Pest Control, Biological; D010936:Plant Extracts / Q000494:pharmacology; D018517:Plant Roots / Q000378:metabolism / Q000469:parasitology; D060888:Real-Time Polymerase Chain Reaction; D017168:Rhabditida / Q000502:physiology*; D017196:Rhabditida Infections / Q000469:parasitology*; D048889:Weevils / Q000502:physiology*
chemical_list: D006844:Hydrocarbons, Cyclic; D010936:Plant Extracts; C474392:pregeijerene B