References of "Hance, Thierry"
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See detailLa carte blanche : Enjeux de la Politique agricole commune en Wallonie : une volonté de découpler nature et agriculture ?
Jacquemart, Anne-Laure; Dendoncker, Nicolas; Dufrêne, Marc ULg et al

Article for general public (2014)

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See detailTechnologie de production de masse d’insectes - INSECTECH
Richard, Gaetan ULg; Hance, Thierry; Fauconnier, Marie-Laure ULg et al

Report (2014)

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See detailThe facultative bacterial symbiont Serratia symbiotica in Acyrtosiphon pisum confer resistance to Aphidius ervi
Attia, Sabrine; Foray, Vincent; Louâpres, Philippe et al

Poster (2014)

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See detailDoes the facultative bacteria Serratia symbiotica influence the foraging strategies of aphid parasitoids?
Attia, Sabrine; Louâpre, Philippe; Foray, Vincent et al

Poster (2014)

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See detailTechnologie de production de masse d’insectes - INSECTECH
Richard, Gaetan ULg; Hance, Thierry; Fauconnier, Marie-Laure ULg et al

Report (2013)

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See detailProteomic Investigation of Aphid Honeydew Reveals an Unexpected Diversity of Proteins
Sabri, Ahmed; Vandermoten, Sophie ULg; Leroy, Pascal et al

in PLoS ONE (2013), 8(9),

Aphids feed on the phloem sap of plants, and are the most common honeydew-producing insects. While aphid honeydew is primarily considered to comprise sugars and amino acids, its protein diversity has yet ... [more ▼]

Aphids feed on the phloem sap of plants, and are the most common honeydew-producing insects. While aphid honeydew is primarily considered to comprise sugars and amino acids, its protein diversity has yet to be documented. Here, we report on the investigation of the honeydew proteome from the pea aphid Acyrthosiphon pisum. Using a two-Dimensional <br />Differential in-Gel Electrophoresis (2D-Dige) approach, more than 140 spots were isolated, demonstrating that aphid honeydew also represents a diverse source of proteins. About 66% of the isolated spots were identified through mass spectrometry analysis, revealing that the protein diversity of aphid honeydew originates from several organisms (i.e. the host aphid and its microbiota, including endosymbiotic bacteria and gut flora). Interestingly, our experiments also allowed to identify some proteins like chaperonin, GroEL and Dnak chaperones, elongation factor Tu (EF-Tu), and flagellin that might act as mediators in the plant-aphid interaction. In addition to providing the first aphid honeydew proteome analysis, we propose to reconsider the importance of this substance, mainly acknowledged to be a waste product, from the aphid <br />ecology perspective. [less ▲]

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See detailFumigant toxicity of Mentha pulegium and Citrus aurantium essential oils to Tetranychus urticae (Acari: Tetranychidae) and Phytoseiulus persimilis (Acari: Phytoseiidae)
Attia, Sabrine; Grissa, K.L.; Lognay, Georges ULg et al

in Boeckx; Bossier, Peter; Smagghe, Guy (Eds.) et al Proceedings of the 65th international symposium on crop protection (2013, May 21)

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See detailCompte-rendu et apport de la conférence-débat : « Nature, conditionnalité et verdissement de la PAC : un tournant wallon ? ». 9 novembre 2011. Espace Senghor, Gembloux, Belgique.
Piqueray, Julien ULg; Richard, Catherine ULg; Walot, Thierri et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2013), 17

Recently, the European Union (EU) proposed a reform project for the Common Agricultural Policy (CAP). One of the proposed reforms consists in imposing to set aside 7% of arable land for biodiversity ... [more ▼]

Recently, the European Union (EU) proposed a reform project for the Common Agricultural Policy (CAP). One of the proposed reforms consists in imposing to set aside 7% of arable land for biodiversity support purposes. About this proposal, a conference was hold in Gembloux, Belgium, on 9th November 2011. Such systems already exist in neighboring countries. French and Swiss systems were displayed in order to highlight their advantages and limits. Scientific arguments subtending such policies were presented. It was shown that creation of semi-natural elements in the agricultural matrix should be efficient to promote biodiversity. Both the quantity and the quality of these elements should be considered. Also, biodiversity is likely to provide services to agriculture, notably crop pollination and pest control. Currently, uncertainties remain on eligible areas to reach the 7% threshold. However, based on most probable scenarios, the current likely eligible areas cover only 4.3% of arable land in Wallonia. Less than 20% of Walloon farms already reach the 7% threshold proposed by the EU. If the European project is approved, it will therefore be of first importance to have a societal recognition toward farmers for their effort. To optimize positive effects of the policy on biodiversity, it is also imperative to make sure that a high biological quality is reached in the areas dedicated to biodiversity and to monitor this quality in the light of clearly defined objectives. Economical, societal and environmental issues should all be considered when applying this policy in order to improve agriculture sustainability and to stop biodiversity decline in agricultural landscapes. [less ▲]

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See detailAcaricidal activities of Santolina africana and Hertia cheirifolia essential oils against the two-spotted spidermite (Tetranychus urticae)
Attia, Sabrine; Grissa, K.L.; Mailleux, A-C et al

in Pest Management Science (2012)

BACKGROUND: Many plant essential oils show a broad spectrum of activity against pests. This study investigated the effects of two essential oils on Tetranychus urticae, one of the most serious pests in ... [more ▼]

BACKGROUND: Many plant essential oils show a broad spectrum of activity against pests. This study investigated the effects of two essential oils on Tetranychus urticae, one of the most serious pests in the world. RESULTS: The chemical composition of the two oils was characterised by GC-MS. The most abundant component in the Santolina africana (Jord. & Fourr) oil was terpinen-4-ol (54.96%), while thymol (61%) was prevalent in the Hertia cheirifolia (L.) oil. Mortality and fecundity were measured upon treatment with oil concentrations ranging from 0.07 to 6.75 mg L-1 with a Potter spray tower.Mite mortality increased with oil concentration, with LC50 values of 2.35 mg L-1 for S. africana and 3.43mg L-1 for H. cheirifolia respectively. For both oils, a reduction in fecundity was observed at concentrations of 0.07, 0.09 and 0.29mg L-1. Artificial blends of constituents of oils were also prepared and tested with individual constituents missing from the mixture. The results showed that the presence of all constituents was necessary to equal the toxicity of the two natural oils. CONCLUSION: S. africana and H. cheirifolia oils can provide valuable acaricide activitywith significantly lower LC50 values. Thus, these oils cause important mortality and reduce the number of eggs laid by females. [less ▲]

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See detailL’agroécologie : trajectoire et potentiel Pour une transition vers des systèmes alimentaires durables
Stassart, Pierre M ULg; Baret, Philippe; Grégoire, Jean-Claude et al

in Vandam, Denise; Streith, Michel; Nizet, Jean (Eds.) et al Agroéocologie, entre pratiques et sciences sociales (2012)

The aim of this paper is to define a conceptual framework for agroecology. There are two components to our approach. The first one proposes an analysis of what agroecology encompasses today, how its ... [more ▼]

The aim of this paper is to define a conceptual framework for agroecology. There are two components to our approach. The first one proposes an analysis of what agroecology encompasses today, how its definition evolved, and in which sociohistorical contexts it emerged and is currently developing. The second one sets the outlines of agroecology’s interdisciplinary approach. This entails a set of principles that should guide research in support of the development of agroecology and a series of medium-term prospects for research in the European context. This paper’s ultimate aim is to set a working framework. As such, it is also an invitation to have the various scientific communities concerned by the subject take part in dialogue with each other, with the agricultural professions and public administrations so as to allow for the diversity of practices involved, and with civil society and political circles. [less ▲]

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See detailOptimisation of a semiochemical slow-release alginate formulation attractive towards Aphidius ervi Haliday parasitoids
Heuskin, Stéphanie ULg; Lorge, Stéphanie; Godin, Bruno et al

in Pest Management Science (2011)

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-β-farnesene and E-β-caryophyllene) slow-release devices in biological control approaches by attracting ... [more ▼]

BACKGROUND: Optimisation of alginate formulations is described in order to develop semiochemical (E-β-farnesene and E-β-caryophyllene) slow-release devices in biological control approaches by attracting predators and parasitoids of aphids. Various formulation criteria were optimised with respect to semiochemical encapsulation capacity. Moreover, the optimised formulation was characterised by texturometry and confocal microscopy. The slow-release rates of semiochemicals were calculated in laboratory controlled conditions. The attractiveness of semiochemical formulations towards Aphidius ervi was demonstrated by olfactometry. RESULTS: Two major parameters were highlighted in encapsulation optimisation: the type of alginate (Sigma L) and the type of crosslinker ion (Ca2+). Other formulation parameters were optimised: ionic strength (0.5M), Ca2+ (0.2 M) and alginate (1.5%) concentrations and the maturation time of beads in CaCl2 solution (48 h). After physical characterisation of beads, semiochemical slow-release measurements showed that alginate formulations were efficient sesquiterpene releasers, with 503 μg of E-β-farnesene and 1791 μg of E-β-caryophyllene totally released in 35 days. The efficiency of semiochemical alginate beads as attractants for female parasitoids was demonstrated, with high percentages of attraction for semiochemical odours (88 and 90% for E-β-farnesene and E-β-caryophyllene respectively) and significant statistical results. CONCLUSION: Semiochemical alginate beads can be considered as efficient slow-release systems in biological control. These formulations could be very useful to attract aphid parasitoids on crop fields. [less ▲]

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See detailAcaricidal activities of Santolina Africana and Hertia Cheirifolia, two endemic plants of north Africa, on the two spotted spider mite (Tetranychus urticae)
Attia, Sabrine; Grissa, Kaouthar Lebdi; Le Goff, Guillaume et al

Poster (2011, May)

The two-spotted spider mite, Tetranychus urticae Koch, is a worldwide pest which feeds on a large variety of plant families. Because its resistance to acaricides is spreading rapidly, the development of ... [more ▼]

The two-spotted spider mite, Tetranychus urticae Koch, is a worldwide pest which feeds on a large variety of plant families. Because its resistance to acaricides is spreading rapidly, the development of new biological control tactics for population management is crucial. Plant extracts, such as Santolina africana and Hertia cheirifolia (Asteraceae), may represent viable alternatives, since they are currently considered to be minimumrisk pesticides. Although these two plants are known for their biocidal properties, the extract concentration that provides the most efficient control has not yet been precisely determined. In this study, we conducted a series of laboratory experiments to determine the susceptibility of adult females to different concentrations of S. africana and H. cheirifolia extract. These plants were steam-distilled and sprayed using a Potter spray tower. Mortality and fecundity were measured upon treatment with extract concentrations ranging from 0.07 to 6.75 mg/L. Female mortality increased with concentration, with LD50 values of 2.35 mg/L for S. africana and 3.43 mg/L for H. cheirifolia, respectively Reduced fecundity was previously observed at concentrations of 0.07, 0.09 and 0.29 mg/L .The chemical composition of the two oils were characterised by GC-MS. The most abundant components of the S. africana oil were terpinen-4-ol (44%), α- terpineol (11.31%) and borneol (6.73%). Camphor (15.11%), terpinen-4-ol (14.2%), α- terpineol (9.3%) were characteristic of the Hertia oil. [less ▲]

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See detailIn vitro culture of the parasitic wasp Aphidius ervi: Sweet dream or Reality
Sabri, Ahmed ULg; Leroy, Pascal ULg; Haubruge, Eric ULg et al

Poster (2011, March 03)

Aphidius ervi is an entomophagous parasitoid and represents an effective parasitoid of several aphid species that cause great damages in agriculture. Several investigations, for its in vitro mass ... [more ▼]

Aphidius ervi is an entomophagous parasitoid and represents an effective parasitoid of several aphid species that cause great damages in agriculture. Several investigations, for its in vitro mass production, have achieved a limited success and suggest that in vitro culture of this valuable biological control agent is rather closer to a dream than reality. Our work provides a chronological study of A. ervi development, from the oviposition until hatching of the first instar larva, in the body of the pea aphid Acyrthosiphon pisum. We show that this parasitoid has some characteristics in its embryological development that are rather complex and different from most other reported insects, which can be phylogenetically very close. Some of these characteristics concern extraembryonic membranes and could be among the causes of the limited success achieved in the in vitro culture. [less ▲]

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See detailAssessment of the acaricidal activity of several plant extracts on the phytophagous mite Tetranychus urticae (Tetranychidae) in Tunisian citrus orchards
Attia, Sabrine; Grissa, Kaouthar Lebdi; Zeineb, Ghrabi-Gammar et al

in Bulletin de la Société Royale Belge d'Entomologie = Bulletin van de Koninklijke Belgische Vereniging voor Entomologie (2011), 147(I-IV), 71-79

To develop sustainable pest control in Tunisian citrus orchards, the present work aimed to evalute the toxicity of 31 plant extracts obtained from Tunisia and two synthetic acaricides (spirodiclofen and ... [more ▼]

To develop sustainable pest control in Tunisian citrus orchards, the present work aimed to evalute the toxicity of 31 plant extracts obtained from Tunisia and two synthetic acaricides (spirodiclofen and fenbutatin oxide) on the phytophagous mite species Tetranychus urticae (Koch). [less ▲]

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See detailContrôle de Tetranychus urticae par les extraits de plantes en vergers d'agrumes
Attia, Sabrine; Grissa, Kaouthar Lebdi; Ghrabi-Gammar, Zeineb et al

in Entomologie Faunistique = Faunistic Entomology (2011), 63(4), 229-235

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See detailContrôle de Tetranychus urticae par les extraits de plantes en vergers d'agrumes
Attia, Sabrine; Lebdi Grissa, Kaouthar; Ghrabi-Gammar, Zeineb et al

in Entomologie Faunistique = Faunistic Entomology (2011), 63(4), 229-235

Tetranychus urticae est un acarien extrêmement polyphage, reconnu comme un ravageur majeur pour une grande quantité de plantes cultivées. Cet acarien cause d’importants dégâts sur agrumes et ... [more ▼]

Tetranychus urticae est un acarien extrêmement polyphage, reconnu comme un ravageur majeur pour une grande quantité de plantes cultivées. Cet acarien cause d’importants dégâts sur agrumes et principalement sur citronnier, se traduisant par de lourdes pertes économiques. L’objectif de ce travail est de mettre en évidence les propriétés acaricides d'extraits de plantes sur T. urticae. Douze extraits (macérats) issus de 12 plantes et deux acaricides de synthèse (Spirodiclofen et Fenbutatin oxyde) ont été choisis pour les essais en verger de citronniers. Ces résultats montrent que trois macérats extraits d’Allium sativum, A. cepa et Deverra scoparia présentent des propriétés acaricides comparables aux deux acaricides de synthèse qui sont les produits de référence. Cette efficacité perdure jusqu’à plus de 15 jours. Le macérat de D. scoparia a présenté l’activité acaricide la plus toxique et la plus rapide sur la population de T. urticae, 21 jours après traitement par rapport aux autres extraits et par rapport aux produits de référence. Ce travail permettra de mettre en place un programme de lutte intégrée visant le contrôle efficace des tétranyques s’attaquant aux citronniers. Les expériences en verger ont démontré que les extraits végétaux ont un effet acaricide pour T.urticae. [less ▲]

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See detailEffective concentrations of garlic distillate (Allium sativum) for the control of Tetranychus urticae (Tetranychidae)
Attia, Sabrine; Grissa, Kaouthar Lebdi; Mailleux, Anne-Catherine et al

in Journal of Applied Entomology (2011)

The two-spotted spider mite, Tetranychus urticae Koch, is a worldwide pest that feeds on a large variety of plant families. Because its resistance to acaricides is spreading rapidly, the development of ... [more ▼]

The two-spotted spider mite, Tetranychus urticae Koch, is a worldwide pest that feeds on a large variety of plant families. Because its resistance to acaricides is spreading rapidly, the development of new biological control tactics for population management is crucial. Plant extracts, such as garlic extract (Allium sativum Linn.), may represent viable alternatives, because they are currently considered to be minimum-risk pesticides. Although garlic is known for its acaricidal properties, the extract concentration that provides the most efficient control has not yet been precisely determined. In this study, we conducted a series of laboratory experiments to determine the susceptibility of adult females to different concentrations of garlic extract. Fresh garlic cloves were steam-distilled and sprayed using a Potter spray tower. Mortality and fecundity were measured upon treatment with garlic extract concentrations ranging from 0.46 to 14.4 mg/l. Female mortality increased with concentration, with LD50 and LD90 values of 7.49 and 13.5 mg/l, respectively. Reduced fecundity was previously observed at concentrations of 0.36 and 0.74 mg/l. The chemical composition of the Allium sativum distillate was characterized by reversed-phase high-performance liquid chromatography coupled with photodiode array detection, GC/MS and Fast GC-FID against an authentic standard (Standard, Bioextract).Vinyl dithiin, diallyl disulphide, diallyl trisulphide and methyl allyl trisulphide were identified based on their mass spectra. Sesquiterpenoids were identified by their retention index. [less ▲]

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See detailPlacenta-Like Structure of the Aphid Endoparasitic Wasp Aphidius ervi: A Strategy of Optimal Resources Acquisition.
Sabri, Ahmed ULg; Hance, Thierry; Leroy, Pascal ULg et al

in PloS one (2011), 6(4), 18847

Aphidius ervi (Hymenoptera: Braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass ... [more ▼]

Aphidius ervi (Hymenoptera: Braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. In these contexts, a careful analysis of its entire development phases within its host is needed. This paper shows that this parasitoid has some characteristics in its embryological development rather complex and different from most other reported insects, which can be phylogenetically very close. First, its yolkless egg allows a high fecundity of the female but force them to hatch from the egg shell rapidly to the host hemocoel. An early cellularisation allowing a rapid differentiation of a serosa membrane seems to confirm this hypothesis. The serosa wraps the developing embryo until the first instar larva stage and invades the host tissues by microvilli projections and form a placenta like structure able to divert host resources and allowing nutrition and respiration of embryo. Such interspecific invasion, at the cellular level, recalls mammal's trophoblasts that anchors maternal uterine wall and underlines the high adaptation of A. ervi to develop in the host body. [less ▲]

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