| Title: | Priming of cowpea volatile emissions with defense inducers enhances the plant's attractiveness to parasitoids when attacked by caterpillars |
| Author(s): | Sobhy IS; Bruce TJ; Turlings TC; |
| Address: | "Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology, University of Neuchatel, Neuchatel, Switzerland. Department of Plant Protection, Public Service Center of Biological Control (PSCBC), Faculty of Agriculture, Suez Canal University, Ismailia, Egypt. School of Life Sciences, Keele University, Keele, UK" |
| ISSN/ISBN: | 1526-4998 (Electronic) 1526-498X (Linking) |
| Abstract: | "BACKGROUND: The manipulation of herbivore-induced volatile organic compounds (HI-VOCs) via the application of the inducers benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH) and laminarin (beta-1,3-glucan) is known to enhance the attractiveness of caterpillar-damaged cotton and maize plants to parasitoids. To test if this is also the case for legumes, we treated cowpea (Vigna unguiculata var. unguiculata) with these inducers and studied the effects on HI-VOC emissions and the attraction of three generalist endoparasitoids. RESULTS: After the inducers had been applied and the plants subjected to either real or mimicked herbivory by Spodoptera littoralis caterpillars, females of the parasitoids Campoletis sonorensis and Microplitis rufiventris showed a strong preference for BTH-treated plants, whereas Cotesia females were strongly attracted to both BTH- and laminarin-treated plants with real or mimicked herbivory. Treated plants emitted more of certain HI-VOCs, but considerably less indole and linalool and less of several sesquiterpenes. Multivariate data analysis revealed that enhanced wasp attraction after treatment was correlated with high relative concentrations of nonanal, alpha-pinene, (E)-beta-ocimene and (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and with low relative concentrations of indole, (S)-linalool and (E)-beta-farnesene. Inducer treatments had no significant effect on leaf consumption by the caterpillars. CONCLUSION: Our findings confirm that treating cowpea plants with inducers can enhance their attractiveness to biological control agents. (c) 2017 Society of Chemical Industry" |
| Keywords: | Animals *Chemotaxis Female Glucans/metabolism *Herbivory Host-Parasite Interactions Larva/growth & development/physiology Spodoptera/growth & development/*physiology Thiadiazoles/metabolism Vigna/*metabolism Volatile Organic Compounds/*metabolism Wasps/*p; |
| Notes: | "MedlineSobhy, Islam S Bruce, Toby Ja Turlings, Ted Cj eng England 2017/11/21 Pest Manag Sci. 2018 Apr; 74(4):966-977. doi: 10.1002/ps.4796. Epub 2018 Jan 11" |
