Females of herbivorous insects use sensory cues, including olfaction, to select oviposition sites. Olfactory cues are responsive to modifications of the host-odour profile, which may reflect changes in host quality. Through a real-time assessment of odour modification, planteating insects may gain relevant information regarding the nutritional value of the host-plant. Microorganisms such as yeast, bacteria and fungi may colonize plants and modify their volatile emission. In addition, they may also change the nutrtional properties of the plant as food for insects. Here, we examined the oviposition response of grapevine moth Lobesia botrana to volatiles from grape (Vitis vinifera) infected with microorganisms commonly found in vineyards. We hypothesized that the odour of grape infected with yeast would stimulate a higher preference for oviposition compared to the odour of bacteria or fungi. To test our hypothesis, we carried out oviposition assays in which females were allowed to choose between the odour of a non-inoculated grape and that of a grape inoculated with one or more microorganisms. The odour released by a pool of grape-born yeast (Saccharomyces cerevisiae, Zygosaccharomyces rouxii, Metschnikowia pulcherrima, Hanseniaspora uvarum and Pichia anomala) showed a positive effect on oviposition. In contrast, volatiles from Gluconobacter oxydans and Acetobacter aceti, and from the phytopathogenic fungus Botrytis cinerea, deterred female oviposition. The stimulus to lay eggs could be restored when B. cinerea was inoculated on the grape along with the yeasts. We found that the nutritional value of the microorganisms (yeasts>bacteria>fungus) correlated with the oviposition preference. The profile of the odour released by the different microbes was characterized by chemical analysis. Behavioural assay were subsequently carried out employing synthetics. As a first output, a compound isolated from the B. cinerea headspace triggered a dose-deterring effect on grapevine moth oviposition at a comparable level to that obtained with the grape infected with the authentic fungus. In this study volatile compounds released by microbes acted as semiochemicals for grapevine moth oviposition. The behavioural effect of these compounds will be further validated in semi-field and field experiments.

Mraihi, M.; Pertot, I.; Simeone, V.; Tasin, M. (2011). Microbial volatiles affect grapevine moth oviposition. IOBC/WPRS BULLETIN, 72: 157. handle: http://hdl.handle.net/10449/21341

Microbial volatiles affect grapevine moth oviposition

Mraihi, Mohamed;Pertot, Ilaria;Tasin, Marco
2011-01-01

Abstract

Females of herbivorous insects use sensory cues, including olfaction, to select oviposition sites. Olfactory cues are responsive to modifications of the host-odour profile, which may reflect changes in host quality. Through a real-time assessment of odour modification, planteating insects may gain relevant information regarding the nutritional value of the host-plant. Microorganisms such as yeast, bacteria and fungi may colonize plants and modify their volatile emission. In addition, they may also change the nutrtional properties of the plant as food for insects. Here, we examined the oviposition response of grapevine moth Lobesia botrana to volatiles from grape (Vitis vinifera) infected with microorganisms commonly found in vineyards. We hypothesized that the odour of grape infected with yeast would stimulate a higher preference for oviposition compared to the odour of bacteria or fungi. To test our hypothesis, we carried out oviposition assays in which females were allowed to choose between the odour of a non-inoculated grape and that of a grape inoculated with one or more microorganisms. The odour released by a pool of grape-born yeast (Saccharomyces cerevisiae, Zygosaccharomyces rouxii, Metschnikowia pulcherrima, Hanseniaspora uvarum and Pichia anomala) showed a positive effect on oviposition. In contrast, volatiles from Gluconobacter oxydans and Acetobacter aceti, and from the phytopathogenic fungus Botrytis cinerea, deterred female oviposition. The stimulus to lay eggs could be restored when B. cinerea was inoculated on the grape along with the yeasts. We found that the nutritional value of the microorganisms (yeasts>bacteria>fungus) correlated with the oviposition preference. The profile of the odour released by the different microbes was characterized by chemical analysis. Behavioural assay were subsequently carried out employing synthetics. As a first output, a compound isolated from the B. cinerea headspace triggered a dose-deterring effect on grapevine moth oviposition at a comparable level to that obtained with the grape infected with the authentic fungus. In this study volatile compounds released by microbes acted as semiochemicals for grapevine moth oviposition. The behavioural effect of these compounds will be further validated in semi-field and field experiments.
Vitis vinifera
Lobesia botrana
Botrytis cinerea
Yeasts
Bacteria
2011
Mraihi, M.; Pertot, I.; Simeone, V.; Tasin, M. (2011). Microbial volatiles affect grapevine moth oviposition. IOBC/WPRS BULLETIN, 72: 157. handle: http://hdl.handle.net/10449/21341
File in questo prodotto:
File Dimensione Formato  
2011 IOBC 72 Mraihi et al.pdf

non disponibili

Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 28.18 kB
Formato Adobe PDF
28.18 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10449/21341
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact