References of "Verheggen, François"
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See detailDevelopment of biological control formulations incorporating components of plant origin
Heuskin, Stéphanie ULg; Lorge, Stéphanie; Verheggen, François ULg et al

in Journée Scientifique annuelle de la Société Royale de Chimie: Jeudi 14 octobre 2010, Gembloux Agro-Bio Tech, Université de Liège, Chimie verte (2010, October 14)

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been considered within various integrated pest management IPM strategies. Herein, two sesquiterpenoids: E-β ... [more ▼]

Semiochemicals – informative molecules used in insect-insect or plant-insect interactions – have been considered within various integrated pest management IPM strategies. Herein, two sesquiterpenoids: E-β-farnesene and E-β-caryophyllene have been formulated for their potential properties as aphid enemies attractants. Indeed, E-β-farnesene, the alarm pheromone of many aphid species [1], has also been identified as a kairomone by attracting and inducing oviposition of aphid predators (Episyrphus balteatus De Geer (Diptera: Syrphidae)) [2-5] and by attracting aphid parasitoids (Aphidius ervi Haliday (Hymenoptera: Braconidae)) [6, 7]. E-β-caryophyllene was identified as a potential component of the aggregation pheromone of the Asian ladybird, Harmonia axyridis Pallas [8, 9]. The two products have been purified from essential oils of Matricaria chamomilla L. (Asteraceae) and Nepeta cataria L. (Lamiaceae) [10, 11]. Natural and biodegradable slow-release devices have been investigated in order to deliver these molecules. Moreover, due to their sensitivity to oxidation, the sesquiterpenes needed to be protected. For this purpose, alginate (hydrophilic matrix with low oxygen permeability) was used as polymer for the formulations: the main objective was to hold and deliver semiochemical substances in a controlled way. Consequently, a careful selection of alginates was realised for encapsulation. Formulated beads showed different structural and encapsulation properties depending on factors such as polymer concentration, ionic strength, type and concentration of cross-linker ion,... The gel structure influenced diffusion properties. Alginate formulations were characterized by texturometry and by confocal microscopy in order to observe the distribution of semiochemicals in alginate network. The last step consisted in studying release rate of semiochemicals in laboratory-controlled conditions by adapted trapping and Fast-GC procedures [10,11]. [less ▲]

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See detailVolatile collection of cadaveric compounds
Dekeirsschieter, Jessica ULg; Verheggen, François ULg; Haubruge, Eric ULg

Poster (2010, October 14)

Thanatochemistry, also named ''chemistry of death'', is poorly studied and the available information regarding the volatile organic compounds (cadaveric VOCs) released after death are rather limited ... [more ▼]

Thanatochemistry, also named ''chemistry of death'', is poorly studied and the available information regarding the volatile organic compounds (cadaveric VOCs) released after death are rather limited. Thanks to the use of analytical chemistry methods ((TDS)GC-MS, GCxGC-TOF-MS), the olfactive signature of a dead body may be studied during the decomposition process. Different volatile collection techniques are used to study the smell of death. There are passive sampling techniques (Radiello® diffusive sampler) and dynamic sampling technique (pump device). The smell of death is constituted by a blend of hundreds of volatile organic compounds which change during the decay process. Main products detected are sulphur compounds such as sulphur dioxide, dimethyldisulfide and dimethyltrisulfide; alcools (1-butanol, 3-methyl-1-butanol), acids (butanoic acid, 2-methylbutanoic acid, 3-methylbutanoic acid and propanoic acid). Many cyclic hydrocarbons were detected: indole, phenol, p-cresol and piperidin-2-one are some examples. The aldehydes are also present, overall butanal, hexanal, heptanal and nonanal. We however found no trace of cadaverine or putrescine. Our results may have potential implication in a better understanding of the olfactive signature of a human or animal cadaveric corpse. Especially in the field of forensic entomology, these chemical compounds may have an attractive role on the necrophagous insect behaviour. Further studies based on the relationships that may exist between cadaveric VOCs and necrophagous insects are currently conducted at the Department of functional and evolutionary Entomology (GxABT, Ulg). [less ▲]

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See detailStudy of the life cycle of two species of forensic interest carrion beetles (Coleoptera, Silphidae): Thanatophilus sinuatus F. & Necrodes littoralis L.
Dekeirsschieter, Jessica ULg; Verheggen, François ULg; Brostaux, Yves ULg et al

in 17 th Benelux Congress of Zoology: Classic Biology in Modern Times: Programme and Abstracts (2010, October)

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See detailImpact of the Asian ladybeetles’ invasions on agro-ecosystems (Belgium)
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

Conference (2010, September 23)

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See detailBiological control formulations incorporating essential oils' components
Heuskin, Stéphanie ULg; Lorge, Stéphanie; Wathelet, Jean-Paul ULg et al

in Lochynski, Stanislaw; Wawrzenczyk, Czeslaw (Eds.) 41th International Symposium on Essential Oils - Programme and Book of Abstracts (2010, September)

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See detailAlarm pheromones: Chemical signaling in response to danger
Verheggen, François ULg; Haubruge, Eric ULg; Mescher, Mark

in Litwack, Gerald (Ed.) Pheromones (2010)

Many animals respond to the threat of predation by producing alarm signals that warn other individuals of the presence of danger or otherwise reduce the success of predators. While alarm signals may be ... [more ▼]

Many animals respond to the threat of predation by producing alarm signals that warn other individuals of the presence of danger or otherwise reduce the success of predators. While alarm signals may be visual or auditory as well as chemical, alarm pheromones are common, especially among insects and aquatic organisms. Plants too emit chemical signals in response to attack by insect herbivores that recruit the herbivores’ natural enemies and can induce preparations for defense in neighboring plants (or other parts of the same plant). In this chapter we discuss our current understanding of chemical alarm signaling in a variety of animal groups (including social and pre-social insects, marine invertebrates, fish, and mammals) and in plants. We also briefly discuss the exploitation of alarm pheromones as foraging cues for natural enemies. We conclude with a brief discussion of the potential exploitation of alarm signaling to achieve the applied goal of managing pest species. [less ▲]

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See detailInvolvement of odorant cues in the process of superparasitism avoidance
Vandermoten, Sophie ULg; Frere, Isabelle; Hance, Thierry et al

Poster (2010, August)

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See detailInvolvement of odorant cues in the process of superparasitism avoidance
Verheggen, François ULg; Vandermoten, Sophie ULg; Frere, Isabelle et al

Poster (2010, August)

The ability to avoid superparasitism provides a selective advantage to parasitoid females, allowing them to avoid depositing eggs in lower quality host. We observed in a Y-olfactometer that generalist ... [more ▼]

The ability to avoid superparasitism provides a selective advantage to parasitoid females, allowing them to avoid depositing eggs in lower quality host. We observed in a Y-olfactometer that generalist aphid parasitoids, Aphidius ervi and Aphidius rhopalosiphi (Hymenoptera, Braconidae), were more attracted toward non-parasitized than parasitized Sitobion avenae (Hemiptera, Aphididae) colonies. We collected the odors released from healthy aphids and aphids parasitized for 2 and 6 days using an electronic nose. Sitobion avenae alarm pheromone, (E)-ß-farnesene (EßF), was the only chemical identified, and was found in lower quantities in parasitized aphids. Both parasitoid species provided pronounced electrical depolarizations to EßF in electroantennography (EAG), and both were attracted to the latter compound in the Y-olfactometer. Parasitoid attraction was known to be guided by a variety of odorant cues released by plants and hosts, and our results support the hypothesis that the aphid alarm pheromone acts as a kairomone for A. ervi and A. rhopalosiphi. [less ▲]

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See detailLes Silphidae...de nouveaux bio-indicateurs en entomologie forensique?
Dekeirsschieter, Jessica ULg; Verheggen, François ULg; Haubruge, Eric ULg

in VII Conférence Internationale Francophone d'Entomologie: Interactions et Biodiversité (2010, July 09)

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See detailUtilité des composés organiques volatils (COVs) émis par les Diptères nécrophages dans l’estimation de l’intervalle post mortem.
Frederickx, Christine ULg; Dekeirsschieter, Jessica ULg; Verheggen, François ULg et al

Conference (2010, July 09)

L’entomologie forensique s’intéresse à l’étude des insectes et d’autres arthropodes permettant d’estimer la période écoulée entre le décès d’une victime et la découverte du corps, encore appelée ... [more ▼]

L’entomologie forensique s’intéresse à l’étude des insectes et d’autres arthropodes permettant d’estimer la période écoulée entre le décès d’une victime et la découverte du corps, encore appelée intervalle post mortem ou IPM. Actuellement, cet intervalle post mortem est estimé après élevage en laboratoire des œufs, des larves et des pupes des Diptères nécrophages prélevés sur la scène de crime. Afin d’éviter cette mise en élevage, il est possible d’estimer l’âge des pupes de Diptères. A cette fin, nous avons prélevé par microextraction sur phase solide (SPME) les composés organiques volatils émis par les pupes de Diptères tout au long de leur pupaison. Ces composés organiques volatiles sont ensuite analysés par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC-MS). Ces analyses permettront d’une part d’estimer l’IPM plus justement et d’autre part de visualiser l’évolution des composés organiques volatiles émis par les pupes de Diptères nécrophages au cours de leur pupaison. [less ▲]

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See detailAssociation des approches morphologique et moléculaire pour l’identification des vers à soies endémiques de Madagascar (Lasiocampidae, Borocera cajani)
Rakotondramanana, Alihasina; Nguyen, Bach Kim ULg; Verheggen, François ULg et al

Poster (2010, July)

La soie est une matière utilisée par les Malgaches depuis bien avant la colonisation. Cette soie est fabriquée à partir de la collecte de cocons des papillons du genre Borocera spp., ver à soie sauvage ... [more ▼]

La soie est une matière utilisée par les Malgaches depuis bien avant la colonisation. Cette soie est fabriquée à partir de la collecte de cocons des papillons du genre Borocera spp., ver à soie sauvage. On connaît une dizaine d’espèces de vers à soie sauvages endémiques à Madagascar. Ces lépidoptères polyphages se nourrissent surtout des feuilles de Uapaca bojeri et d’autres plantes telles que Dodonea madagascariensis et Psidium guyava. Les critères morphologiques se révèlent insuffisant pour identifier cette diversité d’espèces de vers à soie, surtout au niveau des stades immatures. Afin de pallier à cette incapacité d’identifier les espèces, des méthodes de marqueurs moléculaires, en particulier la RAPD (Random Amplified Polymorphic DNA) et iSSR (inter Simple Sequence Repeat), ont été appliquées. En plus de l’identification des espèces, une étude de la diversité et de la distribution des vers à soie suite à la collecte dans plusieurs forêts éloignées de plusieurs de kilomètres les unes des autres (Arivonimamo, Ambatofinandrahana, Antananarivo). Cette étude a été menée dans le cadre de la conservation de ces espèces de vers à soie endémiques en milieu. Afin d’augmenter durablement les populations de vers à soie endémiques dans les forêts de Uapaca, il est important de déterminer les espèces en présence et les capacités de dispersion de ces dernières. Les techniques d’identification moléculaires développées permettront d’orienter les stratégies de gestion des populations de Borocera et des méthodes de gestion de l’écosystème, appropriables par les gestionnaires et les communautés locales des la forêt à Uapaca bojeri. [less ▲]

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