References of "Verheggen, François"
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See detailVolatile organic compounds released by barley roots attract wireworms
Barsics, Fanny ULg; Fiers, Marie ULg; Haubruge, Eric ULg et al

Poster (2012, February 10)

Wireworms are the soil dwelling larvae of click beetles and are pests of many crops worldwide. Alternatives to insecticide treatments are needed in order to develop integrated management strategies. Our ... [more ▼]

Wireworms are the soil dwelling larvae of click beetles and are pests of many crops worldwide. Alternatives to insecticide treatments are needed in order to develop integrated management strategies. Our work consists in elucidating the role of barley root-emitted volatile organic compounds on the orientation behaviour of Agriotes sordidus wireworms. Using a dual choice olfactometer we have evaluated the attractiveness of a variety of baits ranging from barley roots themselves to isolated root-emitted volatile organic compounds. Wireworms were significantly attracted towards most of the tested baits. Our results should be taken into account in varietal selection, in crop rotation, or in trapping systems aiming at the reduction of the populations of this pest. [less ▲]

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See detailAphid predators sampling in agrosystems in Belgium between 2009 and 2011
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

Poster (2012, February 10)

The Multicolored Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was imported in 1997 in Belgium to control aphid populations. Few years ago after its introduction, this exotic ... [more ▼]

The Multicolored Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was imported in 1997 in Belgium to control aphid populations. Few years ago after its introduction, this exotic insect was well adapted to temperate climate conditions and spread out all over ecosystems in Europe causing decline of other aphidophagous species. In arboreal habitats, H. axyridis is the most dominant Coccinellids but we are still lacking information about this occurrence in agrosystems. An aphidophages sampling between 2009 and 2011 was realized in four agrosystems such as broad bean, wheat, corn and potato. Nevertheless H. axyridis populations rise (5 times) from 2009 to 2011 in 2011, H. axyridis is the third most observed aphidophages after Episyrphus balteatus (De Geer) and Coccinella septempunctata (Linné). H. axyridis is the dominating species in corn with 70.83±6.60 individuals per 100m². [less ▲]

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See detailCharacterization of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) overwintering sites
Fassotte, Bérénice ULg; Durieux, Delphine ULg; Haubruge, Eric ULg et al

Poster (2012, February 10)

The invasive multicoloured Asian ladybird, Harmonia axyridis (Pallas), forms large aggregations inside dwellings to overwinter. In order to highlight the specific features of infested houses, we ... [more ▼]

The invasive multicoloured Asian ladybird, Harmonia axyridis (Pallas), forms large aggregations inside dwellings to overwinter. In order to highlight the specific features of infested houses, we investigated a large number of overwintering sites in Wallonia between 2007 and 2011. These sites were characterized through a survey sent to homeowners confronted to invasion problems. The results indicate that H. axyridis preferentially selects isolated brick houses with red or white fronts to take shelter. Aggregations are mostly located at the first floor, essentially inside south or west oriented rooms. Furthermore, ladybirds generally gathered into wooden windows frames facing south or west, and to a lesser extent, in the upper corners of walls presenting the same orientation. [less ▲]

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See detailImplication of honeydew microflora in ant-aphid mutualism
Fischer, Christophe ULg; Lognay, Georges ULg; Haubruge, Eric ULg et al

Poster (2012, February 10)

Some ant and aphid species can present a mutualistic relationship, ants using aphid honeydew as sugar source and in exchange providing the aphid colony cleaning and protection. From a behavioral point of ... [more ▼]

Some ant and aphid species can present a mutualistic relationship, ants using aphid honeydew as sugar source and in exchange providing the aphid colony cleaning and protection. From a behavioral point of view, this phe-nomenon has been well studied from decades. However, its chemistry and semiochemical mechanisms are still largely unknown. This study aims to identify semiochemicals involved in the establishment of this relation, using both chemical and behavioral approaches. Bioassays revealed that the great-est part of ant attraction toward aphid colonies is due to honeydew volatile compounds; enabling ant scouts to find more quickly aphid colonies and distantly recognize myrmecophilous species. Many of those VOCs seeming to have microbial origins, the main honeydew microorganisms have been isolated and their roles in VOCs production and ant attraction have been investigated. It appeared that honeydew microflora holds a key role in the establishment of ant-aphids mutualistic relationship. [less ▲]

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See detailUse of Chrysoperla carnea larvae for biological control of immature stages of Leptinotarsa decemlineata
Sablon, Ludovic ULg; Haubruge, Eric ULg; Verheggen, François ULg

Poster (2012, February 10)

In laboratory assays, we demonstrated predation of Chrysoperla carnea lacewing larvae against eggs, first and second larval instars of Colorado potato beetle (CPB). When looking at the daily consumption ... [more ▼]

In laboratory assays, we demonstrated predation of Chrysoperla carnea lacewing larvae against eggs, first and second larval instars of Colorado potato beetle (CPB). When looking at the daily consumption, we found that prey consumption by the third larval instar was 3-fold higher compared to the two first instars. Partial or total consumption of prey was also numbered. Different proportions of partial/total consumption were found and these depend on the lacewing larval stage. This study provides new perspectives for possible use of C. carnea as a biological agent to control CPB. Nevertheless, additional work has to be conducted under semi-natural and field to completely evaluate this predatory potential. [less ▲]

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See detailHymenoptera community of pig carcasse in an urban biotope
Frederickx, Christine ULg; Dekeirsschieter, Jessica ULg; Verheggen, François ULg et al

Poster (2012, February 10)

Most reports published in the field of forensic entomology studies are focused on Diptera pattern colonization and are neglecting Hymenoptera succession. Hymenoptera are part of the entomofaunal ... [more ▼]

Most reports published in the field of forensic entomology studies are focused on Diptera pattern colonization and are neglecting Hymenoptera succession. Hymenoptera are part of the entomofaunal colonization of a dead body as parasitoids of fly pupae. However, one should consider Hymenoptera parasitoids in a forensic entomology context to evaluate the time of death. Blowflies parasitoids may indeed be of particular importance as their time of attack is often restricted to a small, well-defined window of developmental time of the insect host. Because these parasitoids also interfere with developmental times of colonizing Diptera, a better understanding of their ecology is needed. [less ▲]

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See detailMicroorganisms from aphid honeydew attract natural enemies and tending ants
Verheggen, François ULg; Leroy, Pascal; Fischer, Christophe ULg et al

Conference (2012, February)

Aphids are some of the most serious pests of cultivated crops worldwide, causing major yield and economic losses. Previous works have demonstrated ants and natural enemies (including ladybeetles and ... [more ▼]

Aphids are some of the most serious pests of cultivated crops worldwide, causing major yield and economic losses. Previous works have demonstrated ants and natural enemies (including ladybeetles and hoverflies) to be able to use aphid volatile chemicals to locate aphid colonies. Here, we report the first isolation of a bacterium from the pea aphid Acyrthosiphon pisum honeydew, Staphylococcus sciuri, which produces kairomones used by the aphidophagous hoverfly Episyrphus balteatus and the Asian Ladybeetle Harmonia axyridis during their search for prey colonies. Some specific semiochemicals produced by S. sciuri were identified as attractants and ovipositional stimulants. Similarly, we have shown scouts of the aphid tending ant species, Lasius niger, to orientate their foraging behaviour toward an Aphis fabae infested plant and we have demonstrated that the odours released by this aphid honeydew were attractive for ant scouts. Again, bacteria were involved in the production of these honeydew semiochemicals. Interestingly, ant scouts were also able to discriminate honeydew odour from A. fabae (usually attended by L. niger) and A. pisum (unattendedby L. niger). Comparison of the volatile and bacteria composition of both aphid species honeydew were attended. [less ▲]

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See detailFast-GC quantifacation of harmonine, the major defense alkaloid of the multicolored Asian ladybird Harmonia axyridis (Pallas)
Fischer, Christophe ULg; Laurent, Pascal ULg; Heuskin, Stéphanie ULg et al

in American Journal of Analytical Chemistry (2012), 3

These last few years the multicolored Asian ladybird, Harmonia axyridis (Pallas), previously introduced in Europe and North America as a biological control agent, has swiftly spread out on those ... [more ▼]

These last few years the multicolored Asian ladybird, Harmonia axyridis (Pallas), previously introduced in Europe and North America as a biological control agent, has swiftly spread out on those territories and turns out to be a pest in several ways. In order to improve understanding of several key points of the biology of this ladybird, a novel fast-GC method of quantification of harmonine, the main defense alkaloid of H. axyridis, has been designed and validated using the accuracy profile concept for concentrations ranging from 13 to 264 µg/individual. This method allows quantifying harmonine in a single insect with a maximal error risk of 20%. For ladybirds collected in spring, mean harmonine concentration observed was 106.6 µg/individual with a very high standard deviation of 80.2 µg/individual, which can easily be explained by the strong asymmetry of the results distribution. Males and females seem equally chemically protected as the harmonine concentration did not significantly differ between sexes. This method is currently used to improve our comprehension of several key points of H. axyridis biology including aggregation behavior and aposematism. [less ▲]

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See detailTesting semiochemicals from aphid, plant and conspecific: attraction of Harmonia axyridis
Leroy, Pascal ULg; Schillings, Thomas ULg; Farmakidis, Julien ULg et al

in Insect Science (2012), 19

Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is an invasive specie affecting the dynamics and composition of several guilds. Nowadays, no biological control method is available to reduce the ... [more ▼]

Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is an invasive specie affecting the dynamics and composition of several guilds. Nowadays, no biological control method is available to reduce the populations of this harmful coccinellid. Attractants and semiochemicals seem to be the best alternative but only few studies have tested the impact of semiochemicals on this Asian lady beetle. In this work, through wind-tunnel experiments, semiochemicals from aphids [Z,E-nepetalactone, (E)-β-farnesene, α-pinene and β-pinene], from coccinellids [(-)-β-caryophyllene] and from the nettle Urtica dioica L. were envisaged as potential attractants. The nettle volatile compounds [(Z)-3-hexenol and (E)-2-hexenal] were extracted using a Clevenger Apparatus® and identified by headspace-GC-MS. The main components of the aphid alarm pheromone as well as a component of the aphid sexual pheromone strongly attracted both sexes of the Asian lady beetle while (-)-β-caryophyllene only attracted few individuals and had no impact on the males. The nettle extract as well as the (Z)-3-hexenol oriented both males and females to the odour source. The (E)-2-hexenal was showed to have no effect on females even if this green leaf volatile attracted males. This study highlighted that some semiochemicals from aphids and from nettle extracts orientated the harlequin ladybird H. axyridis. These volatile compounds could certainly help for an efficient biological control approach against this invasive specie. [less ▲]

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See detailDo root-emitted volatile organic compounds attract wireworms?
Barsics, Fanny ULg; Latine, Rémi ULg; Gfeller, Aurélie ULg et al

in Communications in Agricultural and Applied Biological Sciences (2012), 77(3), 561-567

Wireworms are the soil dwelling larvae of click beetles (Coleoptera: Elateridae). Their importance as crop pests increases since the efficient chemical means to control them cannot be considered anymore ... [more ▼]

Wireworms are the soil dwelling larvae of click beetles (Coleoptera: Elateridae). Their importance as crop pests increases since the efficient chemical means to control them cannot be considered anymore. Therefore, many integrated pest management strategies have been investigated in the past few years. Most of them rely on the understanding of the ecology of the click beetles during their whole life cycle. We focus our work on the chemical ecology of wireworms, more precisely on the root-emitted volatile organic compounds (VOCs) that might intervene in the food-searching process of the larvae by helping them to find a suitable host-plant or by acting as key factors in the belowground defence mechanism of the plant. Here, we present our first results of dual-choice orientation tests in olfactometric pipes. Wireworms (Agriotes sordidus Illiger) were submitted individually to a variety of olfactory baits ranging from entire barley roots (Hordeum vulgare L. var. Quench) to isolated VOCs identified as part of the emitting profile. The latter was described thanks to HS-SPME samplings and GC-MS analysis, for roots grown in the exact same conditions as for the olfactometric experimentations with entire roots. Most of the experimentations gave significant results. When confronted to volatiles emitted by entire roots, wireworms significantly orientated towards the bait (χ²-goodness-of-fit test, χ²=8, P-value=0.005). This result allowed us to follow up with the same device and to progressively vary the nature of the baits. Our protocol should be used for other plant-wireworm species combinations. Our results should be taken into account in varietal selection, in crop rotation, or in trapping systems aiming at the reduction of the populations of wireworms. [less ▲]

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See detailRecensement de Calliphora vicina R.-D., Calliphora vomitoria L. et de Cynomya mortuorum L. (Diptères : Calliphoridae) dans les collections entomologiques des étudiants de Gembloux Agro-Bio Tech sur la période 1995-2009.
Frederickx, Christine ULg; Verheggen, François ULg; Bonnet, Stéphanie ULg et al

in Entomologie Faunistique = Faunistic Entomology (2012), 64(3), 57-62

Durant la période 1995-2009, les étudiants de Gembloux Agro-Bio Tech (Université de Liège) ont capturés des Calliphoridae et plus précisément la sous-famille des Calliphorinae. La sous-famille des ... [more ▼]

Durant la période 1995-2009, les étudiants de Gembloux Agro-Bio Tech (Université de Liège) ont capturés des Calliphoridae et plus précisément la sous-famille des Calliphorinae. La sous-famille des Calliphorinae comporte 9 genres dont les Calliphora et les Cynomya. L’entomofaune belge comprend trois espèces : Calliphora vicina Robineau-Desvoidy 1830, Calliphora vomitoria Linné 1758 et Cynomya mortuorum Linné 1761. L’espèce de Calliphorinae la plus représentée parmi les collections d’étudiants est C. vicina. [less ▲]

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See detailLa forêt de tapia, écosystème endémique de Madagascar : écologie, fonctions, causes de dégradation et de transformation (synthèse bibliographique)
Rakotondrasoa, Olivia Lovanirina; Malaisse, François ULg; Rajoelison, Gabrielle Lalanirina et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(4), 541-552

Cet article constitue une synthèse sur la forêt de tapia (Uapaca bojeri Baill.) de Madagascar en vue de présenter son importance dans le développement de la communauté riveraine via l’amélioration des ... [more ▼]

Cet article constitue une synthèse sur la forêt de tapia (Uapaca bojeri Baill.) de Madagascar en vue de présenter son importance dans le développement de la communauté riveraine via l’amélioration des revenus par ménage. La forêt de tapia est une formation « socio-naturelle », à strate arborée quasi monospécifique et endémique de Madagascar. Elle est localisée uniquement dans les hautes terres malgaches. À part les fonctions écosystémiques, la forêt de tapia abrite différentes ressources naturelles, entre autres les produits forestiers non ligneux et ligneux, qui jouent un rôle important dans l’économie locale informelle. Toutefois, cette formation végétale est menacée par la destruction humaine à travers les feux de brousse, la production de bois de chauffe et de charbon de bois, l’extension de l’agriculture et l’envahissement par des espèces exotiques de reboisement. Subséquemment, la gestion durable et la protection de cette forêt sont essentielles afin que les populations riveraines puissent en profiter de génération en génération [less ▲]

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See detailFast-GC quantification of harmonine, the major defense alkaloid of the multicolored asian ladybird Harmonia axyridis (Pallas)
Fischer, Christophe ULg; Laurent, P; Heuskin, Stéphanie ULg et al

in American Journal of Analytical Chemistry (2012), 3

Detailed reference viewed: 9 (6 ULg)