References of "Verheggen, François"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailForaging wireworms are attracted to root-produced volatile aldehydes
Barsics, Fanny ULiege; Delory, Benjamin M.; Delaplace, Pierre ULiege et al

in Journal of Pest Science (2016)

Soil-dwelling insects are known to react to chemical cues they encounter in the rhizosphere. Whether wireworms (Coleoptera, Elateridae) use root-emitted volatile organic chemicals to localize their host ... [more ▼]

Soil-dwelling insects are known to react to chemical cues they encounter in the rhizosphere. Whether wireworms (Coleoptera, Elateridae) use root-emitted volatile organic chemicals to localize their host plant remains, however, poorly understood. Here, we aimed at identifying chemical cues released by barley roots that attract Agriotes sordidus. In a first behavioral experiment, we assessed the ability of wireworms to orient towards live barley roots, using dual-choice olfactometers suitable for belowground insects. Then, we collected the volatile organic compounds (VOC) produced by barley roots using a dynamic head-space sampling approach. VOC were quantified and identified using gas chromatography—mass spectrometry (GC–MS). The odorant blend is composed of four aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal, and (E,Z)-nona-2,6-dienal. In a second set of dual-choice bioassays, wireworms were attracted towards a synthetic blend of these four major compounds. However, the synthetic blend was not as attractive as live roots, which is partially explained by the absence of CO2, commonly known as a strong attractant for soil-dwelling insects. While CO2 indicates the presence of living material in the vicinity, we hypothesize that additional VOC inform about the plant suitability. A better understanding of these belowground signals would contribute to the development of new integrated control strategies against wireworms. [less ▲]

Detailed reference viewed: 90 (13 ULiège)
Full Text
Peer Reviewed
See detailReview: Implementing biostimulants and biocontrol strategies in the agroecological management of cultivated ecosystems
Le Mire, Géraldine ULiege; Nguyen, Minh ULiege; Fassotte, Bérénice ULiege et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2016)

This review describes the current methods for exploiting and applying plant growth-promoting rhizbacteria (PGPR), elicitors and semiochemical products in contemporary agricultural systems. The future of ... [more ▼]

This review describes the current methods for exploiting and applying plant growth-promoting rhizbacteria (PGPR), elicitors and semiochemical products in contemporary agricultural systems. The future of these biostimulant and biocontrol tools for the sustainable management of agricultural practices is also discussed. Special attention is given to the formulation of these products and the network of interactions taking place in cultivated ecosystems [less ▲]

Detailed reference viewed: 388 (79 ULiège)
Full Text
Peer Reviewed
See detailBacteria may contribute to distant species recognition in ant–aphid mutualistic relationships
Fischer, Christophe ULiege; Detrain, Claire; Thonart, Philippe ULiege et al

in Insect Science (2016)

Mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids ... [more ▼]

Mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids and carbohydrate-rich honeydew for the ants. Questions remained, however, as to the volatile semiochemical factor influencing this relationship. A recent study highlighted the role of bacterial honeydew volatile compounds in ant attraction. Here, ant’s ability to distantly discriminate two aphid species was investigated based on bacterial honeydew semiochemicals emissions using a two-way olfactometer. Both the mutualistic black bean aphid (Aphis fabae L.) and the non-myrmecophilous pea aphid (Acyrthosiphon pisum Harris) were found to be attractive for the black garden ant (Lasius niger L.). The level of attraction was similar in both assays (control versus one of the aphid species). However, when given a choice between these two aphid species, ants showed a significant preference for Aphis fabae. Honeydew volatiles, mostly from bacterial origins, are known to be a key element in ant attraction. Using the same olfactometry protocol, the relative attractiveness of volatiles emitted by honeydews collected from each aphid species and by bacteria isolated from each honeydew was in investigated. Again, ants significantly preferred volatiles released by Aphis fabae honeydew and bacteria. This information suggests that microbial honeydew volatiles enable ants to distantly discriminate aphid species. These results emphasize the importance of investigating the presence and potential effects of microbes in insect symbioses. [less ▲]

Detailed reference viewed: 98 (12 ULiège)
Full Text
Peer Reviewed
See detailPreliminary studies on Imbrasia oyemensis, a valuable non-wood forest productinCameroon
Tabi Eckebil, Paule Pamela; Verheggen, François ULiege; Sonwa, Denis Jean et al

in Nature et Faune (2016), 30(2), 73-78

La consommation d’insectes occupe une grande place dans le domaine de la sécurité alimentaire des peuples d’Afrique, d’Asie et d’Amérique latine. Imbrasia oyemensis (Saturniidae) est une chenille ... [more ▼]

La consommation d’insectes occupe une grande place dans le domaine de la sécurité alimentaire des peuples d’Afrique, d’Asie et d’Amérique latine. Imbrasia oyemensis (Saturniidae) est une chenille comestible, classée comme Produit Forestier Non Ligneux (PFNL). Elle est inféodée à Entandrophragma cylindricum dénommé « Sapelli », classée parmi les principales essences de bois d’œuvre d’Afrique centrale destinée à l’export. L’exploitation de cette essence de bois d’œuvre pourrait donc être concurrentielle pour les populations locales, qui pourraient se trouver privées de cette ressource non ligneuse qu’est la chenille. Ce papier présente les résultats préliminaires d’une étude qui visait à déterminer les caractéristiques morphologiques des arbres impliquées dans la sélection du site de ponte des papillons. Les larves d’I.oyemensis se retrouvent principalement sur des individus co-dominant ou dominant ayant déjà atteint le diamètre de fructification régulière. Ces résultats fournissent des pistes utiles comme point de départ aux études sur l’écologie de la chenille en relation avec son arbre hôte. [less ▲]

Detailed reference viewed: 64 (6 ULiège)
Full Text
Peer Reviewed
See detailSynthèse bibliographique sur le comportement de recherche de l’hôte chez la punaise de lit (Cimex lectularius) et applications dans le cadre de la lutte intégrée
Legrand, Pauline ULiege; Verheggen, François ULiege; Haubruge, Eric ULiege et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), 20(2),

This study analyzes host-seeking behavior in the common bed bug, Cimex lectularius, paying particular attention to human stimuli involved in this orientation process. The potential applications in ... [more ▼]

This study analyzes host-seeking behavior in the common bed bug, Cimex lectularius, paying particular attention to human stimuli involved in this orientation process. The potential applications in integrated pest management are discussed. The common bed bug is an obligate hematophagous that has been associated with humans for millennia. When searching for food, this insect relies for orientation on signals produced by its hosts. Carbon dioxide emitted by human respiration is more attractive to bugs than body heat. The response of bed bugs to other volatile organic compounds released by the human body has been tested, but their perception and behavioral impact are not always studied together, and some discrepancies occasionally appear. Currently, carbon dioxide is the most efficient lure for bed bugs, although real human bait is more attractive. Some home-made traps baited with dry ice are more efficient than other traps using complicated chemical blends. Dry ice seems to be more efficient as a lure than complex chemical blends, and it can be used in simple traps. Our knowledge of host-seeking behavior in bed bugs is still partial and new questions are constantly arising. Further efforts in the study of the chemical ecology of this process are needed in order to improve the management of this pest. The control of bed bugs in European countries appears to be a major challenge for the years to come. [less ▲]

Detailed reference viewed: 25 (8 ULiège)
Peer Reviewed
See detailDo changes in atmospheric CO2 concentration affect aphid alarm signaling?
Boullis, Antoine ULiege; Appeldoorn, Claire; Oostrom, Marjolein et al

Conference (2015, November 06)

The effects of global atmospheric changes on vegetation and associated insect populations are increasingly studied, but how these gases affect the interactions between herbivore insects and their natural ... [more ▼]

The effects of global atmospheric changes on vegetation and associated insect populations are increasingly studied, but how these gases affect the interactions between herbivore insects and their natural enemies is less clear. As the efficacy of natural enemies is governed largely by behavioral mechanisms, changes in the behavior of insect prey defenses can change the dynamics of insect populations. The impact of increases in atmospheric carbon dioxide (CO2) concentrations on aphid population dynamic is well documented. However, few publications about their chemical ecology are reported. Aphids are using many chemical signals to communicate with each other or with their environment. For example aphids produce an alarm pheromone to signal the presence of a natural enemy in the colony. For our experiments, aphids Acyrthosiphon pisum (Harris) were reared on Vicia faba L. in home-made Plexiglas® chambers, allowing us to control the CO2 concentration, temperature and humidity. Aphids were reared under both ambient (aCO2 ≈ 400 ppm) and elevated (eCO2 ≈ 800 ppm) CO2 concentration for several generations. Here we quantified the emission of (E)-β-Farnesene (EβF - main compound of alarm pheromone) released by predated aphids reared under ambient or elevated CO2 concentration, with two different methods: a real-time analysis, and the total amount analysis. The EβF content of whole aphid bodies was also analyzed, as well as the escape behavior of aphid colony according to the growing conditions of aphid populations. These results will be discussed in terms of biological control in future climate. [less ▲]

Detailed reference viewed: 109 (14 ULiège)
Peer Reviewed
See detailMultitrophic interactions between plants-viruses-aphidiphagous
Bosquée, Emilie ULiege; Chevalier Mendes Lopes, Thomas ULiege; Boullis, Antoine ULiege et al

Conference (2015, November 06)

Detailed reference viewed: 63 (37 ULiège)
See detailTuta absoluta (Lepidoptera: Gelechiidae) development on wild and cultivated plant species
Bawin, Thomas ULiege; Dujeu, David ULiege; Fagan, Maud et al

Conference (2015, August 24)

Introduction: The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important solanaceous crop plants, including tomatoes and potatoes ... [more ▼]

Introduction: The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important solanaceous crop plants, including tomatoes and potatoes. Little is known about the ability of the microlepidoptera to encounter and develop on alternative wild and agricultural plant species. These plants could provide refuges and have to be identified for more efficient integrated management strategies. Objectives: In the present study, we assessed under laboratory conditions the ability of T. absoluta to develop on such plant species referred as potential hosts in the literature, including Solanaceae, Chenopodiaceae, Convolvulaceae, Fabaceae, and Malvaceae. Materials and methods: For each plant species, fitness tests were performed in Petri dishes by isolating single individuals with excised leaf. Two choice behavioral assays were performed in flying tunnels. Volatile organic compounds released by solanaceous plants were trapped using a dynamic collection system, and analyzed by GC-MS. Results: We found that Solanum species allowed higher larval survivability and shorter development time (from egg to adult emergency) compared to the other plants. Non-solanaceous plants were not able to sustain T. absoluta larvae. Two choice behavioral assays revealed that adult distribution and female oviposition did not differ between Solanum species, which were preferred to other tested solanaceous plants. The hypothesis that female host plant choice is influenced by plant volatile organic compounds was tested. Solanum volatile profiles showed similarities, and were presenting quantitative and qualitative differences with the other tested solanaceous plants, providing some explanations in the observed behavioral discrimination. Further electrophysiological and behavioral assays are required to confirm the effect of specific chemicals on the choice of the oviposition site in T. absoluta. Conclusion: It can be concluded that Solanum species are the more suitable hosts for T. absoluta development. Other solanaceous plant species could be opportunistically colonized with little incidence but care should be taken in these results as genetic variability in insects and plants, as well as plant physiological state, might have an impact on the pest survivability. [less ▲]

Detailed reference viewed: 76 (9 ULiège)
Full Text
See detailDoes elevation in atmospheric CO2 concentration impact aphid alarm signaling?
Boullis, Antoine ULiege; Appeldoorn, Claire; Oostrom, Marjolein et al

Poster (2015, August 24)

The effect of global atmospheric changes on interactions between vegetation and phytophagous insects is well studied since several years, but how does these changes affect the interactions between ... [more ▼]

The effect of global atmospheric changes on interactions between vegetation and phytophagous insects is well studied since several years, but how does these changes affect the interactions between herbivore insects and their natural enemies is less clear. Impact of an increase in CO2 concentration on aphids is also well documented, but few publications focused on their chemical ecology. When endegered, aphids emit an alarm pheromone (generally composed of only one molecule: (E)-Beta-Farnesene) to induce an escape behavior in the colony. Here, we studied how an increase in CO2 concentration affects the alarm signaling mechanisms of the aphid Acyrthosiphon pisum, focusing on the production, the emission (under attack) and the perception of this signal. [less ▲]

Detailed reference viewed: 64 (5 ULiège)
Full Text
Peer Reviewed
See detailCould alternative solanaceous hosts act as refuges for the tomato leafminer, Tuta absoluta?
Bawin, Thomas ULiege; Dujeu, David ULiege; De Backer, Lara ULiege et al

in Arthropod-Plant Interactions (2015), 9(4), 425-435

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous plants. The characterization of its effective ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread devastating pest reported to develop on economically important solanaceous plants. The characterization of its effective host range could help to understand and prevent the dispersion behavior of the insect in the environment. In this study, the ability of T. absoluta to locate and develop on wild (Solanum nigrum, Atropa belladonna, Datura stramonium) and cultivated (Solanum tuberosum) solanaceous plant species under laboratory conditions was assessed. Dual-choice behavioral assays performed in flying tunnels (S. tuberosum versus another plant) revealed that adult distribution and female oviposition did not differ between Solanum species, which were preferred to the other tested plants. The volatile molecules released by each tested plant species provide some explanations in the observed behavioral discrimination: S. nigrum and S. tuberosum volatile profiles were similar, and were presenting quantitative and qualitative differences with the other tested Solanaceous plants. To determine whether the host plant choice was adaptive or not, we have finally conducted fitness assays, by rearing T. absoluta larvae on each plant species and have shown that Solanum species allowed higher larval survivability and lower development time (from egg to adult emergency) compared to the other plants. We conclude that Solanum species are suitable host plants for T. absoluta, but other Solanaceous plant species could be opportunistically colonized with fewer incidences. [less ▲]

Detailed reference viewed: 99 (31 ULiège)
See detailVolatile organic compounds emitted by Cavendish and Plantain banana plants
De Clerck, Caroline ULiege; Kherkhofs, Celine; Berhal, Chadi ULiege et al

Poster (2015, May 19)

Detailed reference viewed: 71 (9 ULiège)
See detailTuta absoluta (Lepidoptera: Gelechiidae) development on wild and cultivated plant species
Bawin, Thomas ULiege; Dujeu, David ULiege; Fagan, Maud ULiege et al

Conference (2015, May 19)

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important cultivated solanaceous crop plants, including tomatoes and potatoes. Little ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important cultivated solanaceous crop plants, including tomatoes and potatoes. Little is known about the ability of this microlepidoptera to encounter and develop on alternative wild and agricultural plant species. These plants could provide refuges and have to be identified for more efficient integrated management strategies. In the present study, we assessed under laboratory conditions the ability of T. absoluta to develop on such plant species referred as potential hosts in the literature, including Solanaceae, Chenopodiaceae, Convolvulaceae, Fabaceae, and Malvaceae. For each plant species, fitness tests were performed in Petri dishes by isolating single individuals with excised leaf. We found that Solanum species allowed higher larval survivability and shorter development time (from egg to adult emergency) compared to the other plants. Non-solanaceous plants were not able to sustain T. absoluta larvae. Two choice behavioral assays performed in flying tunnels revealed that adult distribution and female oviposition did not differ between Solanum species, which were preferred to other tested solanaceous plants. These results appeared to be consistent with survival rates and development times. Because larval survivability depends on the female’s oviposition choice, the hypothesis that host plant choice is influenced by plant volatile organic compounds has to be tested. Volatile organic compounds released by solanaceous plants were trapped using a dynamic collection system, and analyzed by GC-MS. Solanum volatile profiles showed similarities, and were presenting quantitative and qualitative differences with the other tested solanaceous plants, providing some explanations in the observed behavioral discrimination. Further electrophysiological and behavioral assays are required to confirm the effect of specific chemicals on the choice of the oviposition site in T. absoluta. It can be concluded that Solanum species are the more suitable hosts for T. absoluta development. Other solanaceous plant species could be opportunistically colonized with little incidence but care should be taken in these results as genetic variability in insects and plants, as well as plant physiological state, might have an impact on the pest survivability. [less ▲]

Detailed reference viewed: 93 (12 ULiège)
Peer Reviewed
See detailEfficiency of pheromone-based formulations against phytophagous pests
Fassotte, Bérénice ULiege; Vandereycken, Axel ULiege; Chevalier Mendes Lopes, Thomas ULiege et al

Conference (2015, May 19)

Innovative integrated pest management methods are needed to overcome market withdrawal of synthetic pesticides. Therefore, the identification of environment-friendly bio-products carrying direct or ... [more ▼]

Innovative integrated pest management methods are needed to overcome market withdrawal of synthetic pesticides. Therefore, the identification of environment-friendly bio-products carrying direct or indirect biocide activity is one promising alternative option. Our researches focus on the identification of appropriate formulations releasing volatile organic compounds that are attractant for natural enemies of insect pests. However, the elaboration of slow-release devices that ensure stable and controlled release of active volatile compounds is quite challenging. Here, we developed a formulation based on E-β-farnesene and (-)-β-caryophyllene, these two semiochemicals having strong attractive potential on aphid natural enemies including lady beetles and hoverflies. Both compounds were encapsulated together in alginate gel beads. The blend efficiency was first evaluated through laboratory assays, and then in wheat and broad bean fields, by considering the abundance and diversity of aphids and their natural enemies. [less ▲]

Detailed reference viewed: 92 (19 ULiège)
Peer Reviewed
See detailWhat makes the invasive Harmonia axyridis so successful? Six years of research in Gembloux provide additional answers
Fassotte, Bérénice ULiege; Durieux, Delphine ULiege; Vandereycken, Axel ULiege et al

Conference (2015, May 14)

Following the introduction of the invasive species Harmonia axyridis (Pallas) in Europe, many research works were conducted on its ecological, economic and social impacts. Recently, our team has been ... [more ▼]

Following the introduction of the invasive species Harmonia axyridis (Pallas) in Europe, many research works were conducted on its ecological, economic and social impacts. Recently, our team has been involved in the characterization of the behavioral traits making this lady beetle species so successful. The main conclusions of two PhD works will be shortly presented: (1) Through a six-year inventory performed in Belgian agroecosystems, we have demonstrated that H. axyridis has become well established and was among the most abundant aphidophagous predatory species, causing a severe depression of biodiversity, even if communities of aphid predators are still quite diversified. (2) The social issues associated with the establishment of overwintering aggregations in human constructions were also carefully investigated. We have demonstrated the importance of social interactions on the establishment and cohesion of the aggregates. Finally, we have demonstrated that the deposition of a set of saturated and non-saturated hydrocarbons on the surfaces where the lady beetles were settling on, allowed their conspecifics to follow their markings and join the group. [less ▲]

Detailed reference viewed: 69 (13 ULiège)
Peer Reviewed
See detailFirst evidence of a volatile sex pheromone in Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)
Fassotte, Bérénice ULiege; Fischer, Christophe ULiege; Durieux, Delphine ULiege et al

Conference (2015, May 13)

To date, volatile sex pheromones have not been identified in the Coccinellidae family; yet, various studies have suggested that such semiochemicals exist. Here, we collected volatile chemicals released by ... [more ▼]

To date, volatile sex pheromones have not been identified in the Coccinellidae family; yet, various studies have suggested that such semiochemicals exist. Here, we collected volatile chemicals released by virgin females of the multicolored Asian lady beetle, Harmonia axyridis (Pallas), which were either allowed or not allowed to feed on aphids. Virgin females in the presence of aphids, exhibited “calling behavior”, which is commonly associated with the emission of a sex pheromone in several Coleoptera species. These calling females were found to release a blend of volatile compounds that is involved in the remote attraction (i.e., from a distance) of males. Gas Chromatography Mass Spectrometry (GC-MS) analyses revealed that (–)-β-caryophyllene was the major constituent of the volatile blend (ranging from 80 to 86%), with four other chemical components also being present; β-elemene, methyl-eugenol, α-humulene, and α-bulnesene. In a second set of experiments, the emission of the five constituents identified from the blend was quantified daily over a 9-day period after exposure to aphids. We found that the quantity of all five chemicals significantly increased across the experimental period. Finally, we evaluated the activity of a synthetic blend of these chemicals by performing bioassays which demonstrated the same attractive effect in males only. The results confirm that female H. axyridis produce a volatile sex pheromone. These findings have potential in the development of more specific and efficient biological pest-control management methods aimed at manipulating the behavior of this invasive lady beetle. [less ▲]

Detailed reference viewed: 102 (14 ULiège)