References of "Verheggen, François"
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See detailThe semiochemically mediated interactions between bacteria and insects
Leroy, Pascal ULg; Sabri, Ahmed ULg; Verheggen, François ULg et al

in Chemoecology (2011), 21

In natural environment, semiochemicals are involved in many interactions between the different trophic levels involving insects, plants and hosts for parasitoids or prey for predators. These volatile ... [more ▼]

In natural environment, semiochemicals are involved in many interactions between the different trophic levels involving insects, plants and hosts for parasitoids or prey for predators. These volatile compounds act as messengers within or between insect species, inducing particular behaviours such as the localisation of a source of food, the orientation to an adequate oviposition site, the selection of a suitable breeding site and the localisation of hosts or prey. In this sense, bacteria have been shown to play an important role in the production of volatile compounds which ones act as semiochemicals. This review, focusing on the semiochemically-mediated interactions between bacteria and insects, highlights that bacterial semiochemicals act as important messengers for insects. Indeed, in most of the studies reported here, insects respond to specific volatiles emitted by specific bacteria hosted by the insect itself (gut, mouthparts, etc.) or present in the natural environment where the insect evolves. Particularly, bacteria from the families Enterobacteriaceae, Pseudomonaceae and Bacillaceae are involved in many interactions with insects. Because semiochemicals naturally produced by bacteria could be a very interesting option for pest management, advances in this field are discussed in the context of biological control against insect pests. [less ▲]

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See detailInsectes et communication chimique - Techniques et méthodes en écologie chimique
Verheggen, François ULg

Conference (2011, March 17)

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s ... [more ▼]

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s'intéresse au décriptage de ce mode de communication, dont le maitre d'œuvre est le système olfactif des insectes, où antennes et sensilles supportent toute la machinerie physiologique nécessaire à la perception des phéromones et coactones. Pour comprendre le language chimique employé par un insecte, de nombreux outils ont été développés, permettant (1) l'échantillonnage des molécules organiques produites par un insecte, (2) la séparation, la quantification et l'identification des différents constituants du mélange phéromonal,(3) l'étude de la perception par le système olfactif de l'insecte et (4) l'étude du comportement d'un individu mis en présence d'un potentiel bouquet phéromonal ou de l'un de ses constituants. De nombreuses phéromones et coactones ont déjà trouvé le chemin de la valorisation dans le domaine de la protection des cultures. Bien que les insectes d'intérêt agronomique soient les plus largement étudiés, les sémiochimiques employés par d'autres groupes d'insectes font l'objet de nouvelles recherches, avec notamment l'émergence de l'entomologie criminelle [less ▲]

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See detailInsectes et communication chimique - Sémiochimiques et olfaction
Verheggen, François ULg

Conference (2011, March 15)

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s ... [more ▼]

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s'intéresse au décriptage de ce mode de communication, dont le maitre d'œuvre est le système olfactif des insectes, où antennes et sensilles supportent toute la machinerie physiologique nécessaire à la perception des phéromones et coactones. Pour comprendre le language chimique employé par un insecte, de nombreux outils ont été développés, permettant (1) l'échantillonnage des molécules organiques produites par un insecte, (2) la séparation, la quantification et l'identification des différents constituants du mélange phéromonal,(3) l'étude de la perception par le système olfactif de l'insecte et (4) l'étude du comportement d'un individu mis en présence d'un potentiel bouquet phéromonal ou de l'un de ses constituants. De nombreuses phéromones et coactones ont déjà trouvé le chemin de la valorisation dans le domaine de la protection des cultures. Bien que les insectes d'intérêt agronomique soient les plus largement étudiés, les sémiochimiques employés par d'autres groupes d'insectes font l'objet de nouvelles recherches, avec notamment l'émergence de l'entomologie criminelle [less ▲]

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See detailOccurrence of aphid predators in Belgian agro-ecosystems
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

Poster (2011, March 06)

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See detailMicroorganisms from aphids attract hoverflies and enhance their efficacy
Leroy, Pascal ULg; Sabri, Ahmed ULg; Heuskin, Stéphanie ULg et al

Poster (2011, March 05)

Aphids are some of the most serious pests of crops worldwide, causing major yield and economic losses. They damage plants by feeding on the phloem sap, excreting copious amounts of honeydew and, in some ... [more ▼]

Aphids are some of the most serious pests of crops worldwide, causing major yield and economic losses. They damage plants by feeding on the phloem sap, excreting copious amounts of honeydew and, in some cases, vectoring plant diseases. Here, we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri, which is involved in the release of semiochemicals acting as a kairomone for aphid natural enemies. These semiochemicals were identified by Solid-Phase Microextraction (SPME) and Gas Chromatography-Mass Spectrometry (GC-MS). Our results show that this bacterium plays a key role in the interactions between aphids and natural enemies because it is the direct source of volatiles used by the aphidophagous hoverfly Episyrphus balteatus (De Geer) (Diptera: Syrphidae) to locate its aphid prey. Through wind-tunnel experiments, some specific semiochemicals produced by S. sciuri were identified as significant attractants and ovipositional stimulants. Also, assays under greenhouses and in potato fields have demonstrated that a culture medium containing the bacterium S. sciuri strongly attracts and induces the oviposition of hoverflies, enhancing their efficiency as biological control agents. The use of this no pathogenic bacterium could provide a very novel approach towards enhancing the efficacy of biological control agents to control aphids in field crops and greenhouse systems. [less ▲]

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See detailAphid-host plant interactions: Does aphid honeydew exactly reflect the host plant amino acid composition?
Leroy, Pascal ULg; Wathelet, Bernard ULg; Sabri, Ahmed ULg et al

in Arthropod-Plant Interactions (2011), 5

Plants provide aphids with unbalanced and low concentrations of amino acids. Likely, intracellular symbionts improve the aphid nutrition by participating to the synthesis of essential amino acids. To ... [more ▼]

Plants provide aphids with unbalanced and low concentrations of amino acids. Likely, intracellular symbionts improve the aphid nutrition by participating to the synthesis of essential amino acids. To compare the aphid amino acid uptakes from the host plant and the aphids amino acid excretion into the honeydew, host plant exudates (phloem + xylem) from infested and uninfested Vicia faba L. plants were compared to the honeydew produced by two aphid species (Acyrthosiphon pisum Harris and Megoura viciae Buckton) feeding on V. faba. Our results show that an aphid infestation modifies the amino acid composition of the infested broad bean plant since the global concentration of amino acids significantly increased into the host plant in response to aphid infestations. Specifically, the concentrations of two amino acids glutamine and asparagine were strongly enhanced. The amino acid profiles from honeydews were similar for the two aphid species, but the concentrations found into the honeydews were generally lower than those measured in the exudates of infested plants (aphids uptakes). This work also highlights that aphids take large amounts of amino acids into the host plant, especially glutamine and asparagine which are converted into glutamic and aspartic acids but also into other essential amino acids. The amino acid profiles differed between the host plant exudates and the aphid excretion product. Finally, this study highlights that the pea aphid - a “specialist” for the V. faba host plant - induced more important modifications into the host plant amino acid composition than the “generalist” aphid M. viciae. [less ▲]

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See detailLa coccinelle asiatique est-elle l'aphidiphage dominant dans les agro-écosystèmes ?
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

in 9ème Conférence Internationale sur les Ravageurs en Agriculture, Montpellier 26-27 octobre 2011 (2011)

The Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), has been introduced in Western Europe to control aphid and coccid populations in greenhouses. This exotic species rapidly adapted ... [more ▼]

The Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), has been introduced in Western Europe to control aphid and coccid populations in greenhouses. This exotic species rapidly adapted to temperate climatic conditions and invaded all Europe in few years. Now, H. axyridis is causing damages to the ecosystems through e.g. intraguild predation (IGP) with native species. We evaluated, in 2009 and 2010, the occurrence of aphid natural enemies (hoverflies, coccinellids and lacewings) in several agro-ecosystems (corn, wheat, potato, broad bean) in northern Wallonia (Belgium). Five dominating aphidophagous species were observed, in decreasing order of importance: Episyrphus balteatus (De Geer), Chrysoperla carnea sensus lato (Stephens), Coccinella septempunctata (Linné), Harmonia axyridis and Propylea quatuordecimpunctata (Linné). The Multicolored Asian ladybird represents 8,7% of all observed aphidophagous species and 23,9% of coccinellids. Moreover, H. axyridis occurrence is two-times less important than C. 7-punctata. These results highlight that this invasive species is currently not the most abundant in southern Belgium agro-ecosystems and would not influence other aphid predators in those particular ecosystems. [less ▲]

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See detailEarthworms smell microorganisms in soil
Zirbes, Lara ULg; Verheggen, François ULg; Mescher, Mark et al

Poster (2011)

Detailed reference viewed: 29 (2 ULg)