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Turlings, Ted

Nom
Turlings, Ted
Affiliation principale
Fonction
Professeur ordinaire
Email
ted.turlings@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/330

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  • Publication
    Métadonnées seulement
    3-D-Glucopyranosyl-6-methoxy-2-benzoxazolinone (MBOA-N-Glc) is an insect detoxification product of maize 1,4-benzoxazin-3-ones
    (2014)
    Maag, Daniel 
    ;
    Dalvit, Claudio 
    ;
    Thevenet, Damien 
    ;
    Köhler, Angela
    ;
    Wouters, Felipe C.
    ;
    Vassão, Daniel G.
    ;
    Gershenzon, Jonathan
    ;
    Wolfender, Jean-Luc
    ;
    Turlings, Ted 
    ;
    Erb, Matthias 
    ;
    Glauser, Gaetan
    In order to defend themselves against arthropod herbivores, maize plants produce 1,4-benzoxazin-3-ones (BXs), which are stored as weakly active glucosides in the vacuole. Upon tissue disruption, BXs come into contact with ?-glucosidases, resulting in the release of active aglycones and their breakdown products. While some aglycones can be reglucosylated by specialist herbivores, little is known about how they detoxify BX breakdown products. Here we report on the structure of an N-glucoside, 3-?-d-glucopyranosyl-6-methoxy-2-benzoxazolinone (MBOA-N-Glc), purified from Spodoptera frugiperda faeces. In vitro assays showed that MBOA-N-Glc is formed enzymatically in the insect gut using the BX breakdown product 6-methoxy-2-benzoxazolinone (MBOA) as precursor. While Spodoptera littoralis and S. frugiperda caterpillars readily glucosylated MBOA, larvae of the European corn borer Ostrinia nubilalis were hardly able to process the molecule. Accordingly, Spodoptera caterpillar growth was unaffected by the presence of MBOA, while O. nubilalis growth was reduced. We conclude that glucosylation of MBOA is an important detoxification mechanism that helps insects tolerate maize BXs.
  • Publication
    Métadonnées seulement
    Dispersal and persistence of mass released Trichogramma brassicae (Hymenoptera : Trichogrammatidae) in non-target habitats
    (2003)
    Kuske, Stefan
    ;
    Widmer, Franco
    ;
    Edwards, Peter
    ;
    Turlings, Ted 
    ;
    Babendreier, Dirk
    ;
    Bigler, Franz
    Field studies were carried out to evaluate whether inundative releases of Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae) against the European corn borer, Ostrinia nubilalis Hubner (Lepidoptera: Crambidae), can have negative effects on the indigenous arthropod fauna in adjacent non-target habitats. Emigration of released T brassicae from maize fields into non-target habitats was monitored, and its persistence in non-target habitats was assessed throughout the season. For this purpose, sticky traps were installed on metal sticks along transects from the inside of T brassicae treated maize fields into sown wildflower strips and a natural common reed stand. In addition, cards with host eggs were used to monitor Trichogramma within potential overwintering sites. Although the highest numbers of released parasitoids were trapped within maize, a considerable amount of T. brassicae moved into non-target habitats. We found a significant transient increase of T. brassicae in both wildflower strips and reeds and no consistent decrease in numbers of trapped wasps up to 40 m from the maize field borders, when monitored directly following mass releases. Indigenous Trichogramma species were present both in the wildflower strip and reeds, and T. brassicae represented only a minor part of the overall Trichogramma population therein, except for a few days after release. However, a few T brassicae persisted in non-target habitats throughout the season and were still present prior to releases in the subsequent year. These low numbers are not expected to seriously affect populations of native Trichogramma or non-target host species. (C) 2003 Elsevier Science (USA). All rights reserved.
  • Publication
    Métadonnées seulement
    The induction of volatile emissions in maize by three herbivore species with different feeding habits: Possible consequences for their natural enemies
    (: Academic Press Inc, 1998)
    Turlings, Ted 
    ;
    Bernasconi, Marco
    ;
    Bertossa, Rinaldo
    ;
    Bigler, Franz
    ;
    Caloz, Genevieve
    ;
    Dorn, Silvia
    In order to find their prey natural enemies of herbivores often make effective use of plant volatiles that are emitted by plants on which the herbivores have been feeding. The phenomenon of herbivore-induced emissions of attractants has been well investigated for mite-plant interactions and for interactions between leaf feeding caterpillars and plants. Herbivore-induced emissions of chemical signals appear to be common in plants, but little is known about induction by herbivores that have different feeding habits. We obtained more knowledge on this by comparing the volatile emissions induced in maize plants by a folivorous caterpillar (Spodoptera littoralis), a stemborer (Ostrinia nubilalis), and an aphid (Rhopalosiphum maidis). As controls we also measured the emissions of healthy, undamaged plants and plants that were mechanically damaged and then treated with caterpillar regurgitate. Volatiles were collected twice daily for 2 h over a 3-day period after initial infestation or mechanical damage. Quantitatively, the plants infested with S. littoralis emitted by far the most. Their emissions started several hours after initial damage, lasted for the 3 days, and were the highest on the third day. The volatile profile was the same for the regurgitate-treated plants, but here the emissions dropped rapidly after the first day. The plants infested by O. nubilalis emitted the same blend of volatiles, but in much lower quantities, In addition to the known induced maize volatiles, the Ostrinia-damaged plants emitted some highly volatile, still unidentified compounds, which may be specific for the frass of this insect or emitted from the damaged plant stem. The aphids induced no measurable emissions of volatiles in the maize, even after heavy infestation. This is perhaps because several aphids, including R. maidis, barely damage the plant cells, and may not trigger a plant response. These findings suggest that induction of volatiles is the result of cell tissue damage, particularly to the leaves of the plant. This should have consequences also for the search strategies employed by the natural enemies of the respective herbivores, It can be expected that enemies of stemborers use some highly volatile compounds in addition to the known induced compounds. Natural enemies of some aphids may have to resort to other foraging cues, as the plant appears to provide them with no or very little olfactory information. (C) 1998 Academic Press.