References of "Verheggen, François"
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See detailLes phéromones d'alarme dans le règne animal
Verheggen, François ULg; Haubruge, Eric ULg

in Faunistic Entomology - Entomologie Faunistique (2010), 63(4),

Beaucoup d'animaux répondent à la menace de la prédation en produisant des signaux d'alarme qui avertissent les autres individus de la présence de danger ou qui réduisent le succès de prédateurs. Alors ... [more ▼]

Beaucoup d'animaux répondent à la menace de la prédation en produisant des signaux d'alarme qui avertissent les autres individus de la présence de danger ou qui réduisent le succès de prédateurs. Alors que les signaux d'alarme peuvent être de nature visuelle, auditive ou chimique, les phéromones d'alarme sont fréquentes, surtout chez les insectes et les organismes aquatiques. Les plantes aussi émettent des signaux chimiques en réponse à l'attaque par les insectes herbivores qui recrutent les ennemis naturels des ravageurs et qui peuvent induire des mécanismes de défense chez les plantes voisines (ou d'autres parties de la même plante). Dans ce chapitre, nous discutons de notre compréhension actuelle des modes de communications chimiques d’alarme dans les divers groupes d'animaux où ces signaux ont été identifiés (y compris les insectes sociaux et pré-sociaux, les invertébrés marins, les poissons et les mammifères) ainsi que dans le règne végétal. Nous discuterons aussi brièvement l'exploitation des phéromones d'alarme par les ennemis naturels des insectes émettant ces signaux. Nous concluons par une brève discussion de l'exploitation potentielle des signaux d'alarme dans des approches de lutte intégrée contre les espèces nuisibles. [less ▲]

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See detailValidation of a fast gas chromatographic method for the study of semiochemical slow release formulations
Rozet, Eric ULg; Heuskin, Stéphanie ULg; Lorge, Stéphanie et al

in Journal of Pharmaceutical & Biomedical Analysis (2010), 53

The validation of a fast GC-FID analytical method for the quantitative determination of semiochemical sesquiterpenes (E-β-farnesene and β-caryophyllene) to be used in an integrated pest management ... [more ▼]

The validation of a fast GC-FID analytical method for the quantitative determination of semiochemical sesquiterpenes (E-β-farnesene and β-caryophyllene) to be used in an integrated pest management approach is described. Accuracy profiles using total error as decision criteria for validation were used to verify the overall accuracy of the method results within a well defined range of concentrations and to determine the lowest limit of quantification for each analyte. Furthermore it allowed to select a very simple and reliable regression model for calibration curve for the quantification of both analytes as well as to provide measurement uncertainty without any additional experiments. Finally, this validated method was used for the quantification of semiochemicals in slow release formulations. The goal was to verify the protection efficiency of alginate gel beads formulations against oxidation and degradation of sesquiterpenes. The results showed that the alginate beads are adequate slow release devices which protect the bio-active molecules during at least twenty days. [less ▲]

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See detailSynthèse bibliographique : l’écologie chimique des coccinelles
Durieux, Delphine ULg; Verheggen, François ULg; Vandereycken, Axel ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(2), 351-367

This paper reviews the chemical ecology of ladybird beetles (Coleoptera: Coccinellidae) to present the role of semiochemicals involved in plant-ladybird, prey-ladybird and predator-ladybird interactions ... [more ▼]

This paper reviews the chemical ecology of ladybird beetles (Coleoptera: Coccinellidae) to present the role of semiochemicals involved in plant-ladybird, prey-ladybird and predator-ladybird interactions. Ladybird beetles use these compounds to locate their prey, mate, protect themselves from predation or cannibalism, find a shelter to overwinter or ensure a better survival for their offspring. Thorough studies on ladybird behaviours towards these compounds could lead to their practical implementation in integrated strategies using ladybirds to control pests, like aphids or mealybugs. [less ▲]

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See detailAssessment of oviposition site quality by aphidophagous hoverflies: reaction to conspecific larvae
Almohamad, Raki; Verheggen, François ULg; Francis, Frédéric ULg et al

in Animal Behaviour (2010), 79

Aphidophagous predators adapt their foraging behaviour to the presence of conspecific and heterospecific larvae. We studied the effect of the presence of conspecific larvae and their tracks on the ... [more ▼]

Aphidophagous predators adapt their foraging behaviour to the presence of conspecific and heterospecific larvae. We studied the effect of the presence of conspecific larvae and their tracks on the oviposition site selection of an aphid-specific predator, Episyrphus balteatus DeGeer (Diptera: Syrphidae), in two-choice experiments using a leaf disc bioassay. Gas chromatography – mass spectrometry analysis was used to identify the volatile chemicals released from odour extracts of E. balteatus larval tracks. The behavioural effects of these volatile substances on hoverfly females were also evaluated. Our experiments demonstrated that E. balteatus females were deterred from ovipositing when presented with a Vicia faba leaf with aphids and conspecific larvae. The oviposition-deterring stimulus was also active when females were presented with a leaf that contained conspecific larval tracks. A mixture of chemical compounds was found in the volatile pattern of odour extracts of larval tracks. The main volatile chemicals were 3-methylbutanoic acid, 2-methylbutanoic acid, 2-methylpropanoic acid, 3-hydroxy- 2-butanone, hexanoic acid and phenol. Females also laid significantly fewer eggs in response to odorant volatiles emitted from larval extracts. These results highlight that predatory hoverfly females avoid ovipositing in aphid colonies in which conspecific larvae or their tracks are already present, suggesting that this behaviour constitutes a strategy that enables females to optimize their oviposition site and reduce competition suffered by their offspring. [less ▲]

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See detailSémiochimiques et danger - Les phéromones d'alarme
Verheggen, François ULg

Conference (2010)

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See detailThe use of chemical ecology in forensic entomology
Dekeirsschieter, Jessica ULg; Frederickx, Christine ULg; Verheggen, François ULg et al

Conference given outside the academic context (2009)

Detailed reference viewed: 32 (4 ULg)
See detailAphid-ant mutualism: How do aphids focus ant foraging?
Verheggen, François ULg; Detrain, Claire; Diez, Lise et al

Conference (2009, August)

The mutualistic relationships that occur between myrmecophilous aphids and ants are based on the rich food supply that honeydew represents for ants and on the protection they provide against aphid natural ... [more ▼]

The mutualistic relationships that occur between myrmecophilous aphids and ants are based on the rich food supply that honeydew represents for ants and on the protection they provide against aphid natural enemies. While aphid predators and parasitoids actively forage for oviposition sites by using aphid semiochemicals, scouts of aphid-tending ant species would also benefit from locating honeydew resources by orienting toward aphid pheromone sources. The present study aims to identify the chemical factors that attract ants and that maintain their mutualistic relationships with aphids. The perception and behavioral impact of Aphis fabae alarm pheromone, namely (E)-β-farnesene, on Lasius niger were firstly investigated using electroantennography and a four-arm olfactometer. Aphis fabae honeydew sugar composition was subsequently analyzed while the foraging and recruiting behaviour of L. niger scouts towards each of the identified sugars was studied. Clear electrical depolarisations were observed from L. niger scout antennae to stimulations of A. fabae alarm pheromone. Scouts were significantly attracted toward (E)-β-farnesene in the four-arm olfactometer, suggesting for the first time that the latter compound is a key chemical in the establishment of the mutualism. Aphis fabae honeydew consisted of 9 identified mono-, di- and tri-saccharides and 8 hydrocarbons that could not be identified. The main identified sugars were sucrose, fructose, glucose and melezitose. L. niger scouts showed the following drinking preferences for the tested sugars: melezitose = sucrose = raffinose > glucose = fructose > maltose = trehalose = melibiose = xylose, with a recruitment launched toward the first three sugars. Therefore, ant scouts may use aphid semiochemicals to locate at distance an aphid colony and subsequently estimate honeydew quality by tasting it before recruiting conspecifics and establishing a mutualistic relationship. [less ▲]

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See detailFirst record of the 'bathroom mothmidge' Clogmia albipunctata, a conspicuous element of the Belgian fauna that went unnoticed (Diptera: Psychodidae)
Boumans, Louis; Zimmer, Jean-Yves ULg; Verheggen, François ULg

in Phegea (2009), 37(4), 153-160

The 'bathroom fly' Clogmia albipunctata (Williston, 1893) (Diptera: Psychodidae) is a cosmopolitan species that is commonly found in bathrooms, kitchens, sewage treatment plants and compost heaps. Of ... [more ▼]

The 'bathroom fly' Clogmia albipunctata (Williston, 1893) (Diptera: Psychodidae) is a cosmopolitan species that is commonly found in bathrooms, kitchens, sewage treatment plants and compost heaps. Of circumtropical origin, the species probably spread to synanthropic habitats in northern and central Europe during the past decades. The first documented findings in Belgium are discussed, together with general information on the biology and recognition of the species. [less ▲]

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See detailOrigine et évolution du cannibalisme dans les populations animales : pourquoi manger son semblable ?
Alabi, Taofic; Patiny, Sébastien; Verheggen, François ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2009), 13

Le cannibalisme est issu d’une déformation linguistique de la terminologie Arawak (Amérindiens des Antilles) caribal qui signifie courageux. Christophe Colomb l’emploie pour désigner les Indiens des ... [more ▼]

Le cannibalisme est issu d’une déformation linguistique de la terminologie Arawak (Amérindiens des Antilles) caribal qui signifie courageux. Christophe Colomb l’emploie pour désigner les Indiens des Caraïbes réputés pour être des mangeurs d’hommes. Le cannibalisme est largement répandu au sein du règne animal. Sa pratique au sein de l’espèce humaine remonte au Paléolithique et persiste encore dans certaines sociétés actuelles, bien qu’elle ne répond pas exclusivement à des besoins alimentaires comme chez les autres espèces animales. Au regard de sa large distribution, il y a lieu de s’interroger sur les causes, origines et avantages évolutifs de ce comportement au sein du règne animal. Le cannibalisme est induit soit par des facteurs écologiques directement liés à une insuffisance des ressources alimentaires, à de fortes densités d’individus et à une hétérogénéité structurale de la population, soit par des facteurs sociaux comme des besoins de reproduction, ou des contraintes de soins parentaux face à une progéniture trop nombreuse. Les avantages de ce comportement sont les gains nutritionnel et énergétique, les gains de territoire pour vivre et se développer. Par contre, les inconvénients résident dans la réduction des effectifs et de la variabilité génétique de la population, ainsi que dans la possibilité de transmission de parasites, virus et de maladies. [less ▲]

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See detailTreatment method using biological control
Leroy, Pascal ULg; Capella, Quentin ULg; Verheggen, François ULg et al

Patent (2009)

L’invention porte sur un dispositif de prévention et de lutte contre les insectes ravageurs, en particulier contre les pucerons (aphidiens)) de végétaux. L’invention porte donc également sur la méthode de ... [more ▼]

L’invention porte sur un dispositif de prévention et de lutte contre les insectes ravageurs, en particulier contre les pucerons (aphidiens)) de végétaux. L’invention porte donc également sur la méthode de production de ce dispositif. L’invention porte également sur l’utilisation de ce dispositif à proximité d’un végétal susceptible d’être infesté ou déjà infesté par un insecte ravageur tel que le puceron. [less ▲]

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See detailComparison of age-dependent quantitative changes in the male labial gland secretion of Bombus terrestris and Bombus lucorum.
Zacek, Petr; Kalinova, Blanka; Sobotnik, Jan et al

in Journal of Chemical Ecology (2009), 35(6), 698-705

Age-related changes of antennal-active components of male labial gland extracts were studied in two closely related bumblebee species, Bombus terrestris and B. lucorum. In B. terrestris, compounds ... [more ▼]

Age-related changes of antennal-active components of male labial gland extracts were studied in two closely related bumblebee species, Bombus terrestris and B. lucorum. In B. terrestris, compounds eliciting electroantennogram (EAG) responses of virgin queens were ethyl dodecanoate, 2,3-dihydrofarnesal, 2,3-dihydrofarnesol, hexadecan-1-ol, octadeca-9,12,15-trien-1-ol, and geranylcitronellol. Compounds that elicited EAG responses from queens of B. lucorum were ethyl dodecanoate, ethyl tetradec-7-enoate, ethyl tetradec-9-enoate, ethyl hexadec-9-enoate, hexadecan-1-ol, hexadec-7-enal, octadeca-9,12-dien-1-ol, octadeca-9,12,15-trien-1-ol, and octadecan-1-ol. Quantities of these compounds in the labial glands changed significantly over the lifetime of the respective males of the two species. In both species, concentrations of the respective compounds reached their maximum within seven days after eclosion. Subsequently, a rapid decrease in the amount of EAG-active compounds occurred in B. terrestris, whereas in B. lucorum the amount of active compounds stayed approximately constant or decreased at a slow rate. Microscopy showed that in B. terrestris secretory cells of the labial glands undergo apoptosis from the fifth to the tenth day of life, whilst in B. lucorum labial gland cells remain unchanged throughout the life of the males. [less ▲]

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