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  • Publication
    Accès libre
    Identification of host-plant chemical stimuli for the European grape berry moth Eupoecilia ambiguella
    (2011)
    Schmidt-Büsser, Daniela
    ;
    von Arx, Martin
    ;
    Connétable, Sophie
    ;
    Olfaction is of major importance for survival and reproduction in moths. Males possess highly specific and sensitive olfactory receptor neurones to detect female sex pheromones. However, the capacity of male moths to respond to host-plant volatiles is relatively neglected and the role that such responses could play in the sensory ecology of moths is still not fully understood. The present study aims to identify host-plant stimuli for the European grape berry moth Eupoecilia ambiguella Hb. (Tortricidae, Lepidoptera), a major pest of vine in Europe. Headspace volatiles from Vitis vinifera L. cv. Pinot Noir, Vitis vinifera subsp. sylvestris and five other host-plant species comprising five different families are analyzed by gas chromatography linked to electroantennogram (EAG) recording from male E. ambiguella antennae and by gas chromatography-mass spectrometry. This procedure identifies 32 EAG-active compounds, among them the aliphatic compounds 1-hexanol, (Z)-3-hexenol, (Z)-3-hexenyl acetate and 1-octen-3-ol; the terpenes limonene, β-caryophyllene and (E)-4,8-dimethyl-1,3,7-nonatriene; and the aromatic compounds benzaldehyde and methyl salicylate. Male and female E. ambiguella show similar EAG response amplitudes to individual chemical stimuli and also to mixtures of plant volatiles, as represented by essential oils from ten other plant species. This possibly indicates a common role for plant compounds in the sensory ecology of the two sexes of E. ambiguella.
  • Publication
    Accès libre
    Host plant volatiles serve to increase the response of male European grape berry moths, Eupoecilia ambiguella, to their sex pheromone
    (2009)
    Schmidt-Büsser, Daniela
    ;
    von Arx, Martin
    ;
    The European grape berry moth is an important pest in vineyards. Males respond to the female-produced sex pheromone released from a piezo nebulizer in a dose-dependent manner in a wind tunnel: <50% arrive at the source at 5–50 pg/min (underdosed), 80% arrive at 100 pg/min to 10 ng/min (optimal) and <20% arrive at 100 ng/min (overdosed). Males responding to overdosed pheromone show in flight arrestment at 80 cm from the source. Host plant chemostimuli for Eupoecilia ambiguella increase the responses of males to underdosed and overdosed pheromone. (Z)-3-hexen-1-ol, (+)-terpinen-4-ol, (E)-β-caryophyllene and methyl salicylate released with the underdosed pheromone cause a significant increase in male E. ambiguella flying to the source. Time–event analysis indicates a positive correlation between faster activation and probability of source contact by the responding males. The four host plant compounds added to the overdosed pheromone permitted males to take off faster and with a higher probability of flying to the source. This suggests that perception of host plant products with the sex pheromone facilitates male E. ambiguella to locate females on host plants, lending credence to the hypothesis that plant products can signal rendezvous sites suitable for mating.
  • Publication
    Accès libre
    Plant Volatiles Enhance Behavioral Responses of Grapevine Moth Males, Lobesia botrana to Sex Pheromone
    Von Arx, Martin
    ;
    Schmidt-Büsser, Daniela
    ;
    Plant volatiles play an important role in the lives of phytophagous insects, by guiding them to oviposition, feeding and mating sites. We tested the effects of different host-plant volatiles on attraction of Lobesia botrana males to the female-produced sex pheromone, in a wind tunnel. Addition of volatile emissions from grapevines or individual plant volatiles to pheromone increased the behavioural responses of L. botrana males over those to pheromone alone. At a low release rate (under-dosed) of pheromone, addition of (E)-β-caryophyllene, (Z)-3-hexenyl acetate, 1-hexanol, or 1-octen-3-ol increased all behavioral responses, from activation to pheromone source contact, while addition of (E)-4,8-dimethyl-1,3,7-nonatriene, (E)-β-farnesene, (Z)-3-hexenol, or methyl salicylate affected only the initial behavioural responses. Dose–response experiments suggested an optimal release ratio of 1:1000 (sex pheromone: host plant volatile). Our results highlight the role of plant volatiles in the sensory ecology of L. botrana.