http://hdl.handle.net/2268/141 Chercher dans ce canal chercher http://orbi.ulg.ac.be/simple-search http://hdl.handle.net/2268/149112 Titre: Identification of lectins as virus competitors in aphid vectors : from fundamental to applied approaches <br/> <br/>Auteur, co-auteur: Bosquée, Emilie; Vandermoten, Sophie; Yu, Wen-Juan; Ronling, Yin; Liu, Yong; Ju-Lian, Chen; Francis, Frédéric Thu, 23 May 2013 15:12:08 GMT http://hdl.handle.net/2268/149103 Titre: Alternative methods for virus control: the role of symbionts and lectins in viral transmission <br/> <br/>Auteur, co-auteur: Bosquée, Emilie; Chen, Ju Lian; Yong, Lui; Francis, Frédéric Thu, 23 May 2013 14:58:10 GMT http://hdl.handle.net/2268/148942 Titre: Diversity of culturable bacteria including Pantoea in wild mosquito Aedes albopictus <br/> <br/>Auteur, co-auteur: Claire Valiente, Claire; Tran, Florence Hélène; Raharimalala, Fara Nantenaina; Ravelonandro, Pierre; Mavingui, Patrick <br/> <br/>Résumé: Background: The microbiota has been shown to play an important role in the biology of insects. In recent decades, significant efforts have been made to better understand the diversity of symbiotic bacteria associated with mosquitoes and assess their influence on pathogen transmission. Here, we report the bacterial composition found in field-caught Aedes albopictus populations by using culture-dependent methods. Results: A total of 104 mosquito imagos (56 males and 48 females) were caught from four contrasting biotopes of Madagascar and their bacterial contents were screened by plating whole body homogenates on three different culture media. From 281 bacterial colony types obtained, amplified ribosomal DNA restriction analysis (ARDRA) showed they had 40 distinct ribotypes. Sequencing and BLAST analysis of the 16S rDNA genes responsible for each representative profile made it possible to identify 27 genera distributed in three major phyla. In female mosquitoes, bacterial isolates were mostly Proteobacteria (51.3%) followed by Firmicutes (30.3%) and Actinobacteria (18.4%). Conversely, Actinobacteria was the most abundant phylum in male mosquitoes (48%) followed by Proteobacteria (30.6%) and Firmicutes (20.4%). The relative abundance and composition of isolates also varied between sampling sites, ranging from 3 distinct families in Ankazobe to 8 in Tsimbazaza Park, and Toamasina and Ambohidratrimo. Pantoea was the most common genus in both females and males from all sampling sites, except for Ambohidratrimo. No differences in genome size were found between Pantoea isolates from mosquitoes and reference strains in pulse field gel electrophoresis. However, according to the numbers and sizes of plasmids, mosquito isolates clustered into three different groups with other strains isolated from insects but distinct from isolates from the environment. Conclusions: The recent upsurge in research into the functional role of the insect microbiota prompts the interest to better explore the role some bacteria detected here may have in the mosquito biology. Future studies of culturable bacteria might decipher whether they have a biological role in the invasiveness of Ae. albopictus. As a possible candidate for paratransgenesis, the predominant genus Pantoea will be characterized to better understand its genetic contents and any possible influence it may have on vector competence of Ae. albopictus. Thu, 23 May 2013 06:43:00 GMT http://hdl.handle.net/2268/148941 Titre: Acinetobacter is more prevalent than Asaia in natural populations of the mosquito vector Aedes albopictus with isolates showing diverse genomic architecture and substrate utilization. <br/> <br/>Auteur, co-auteur: Minard, Guillaume; Tran, Florence Hélène; Raharimalala, Fara Nantenaina; Hellard, Eléonore; Ravelonandro, Pierre; Mavingui, Patrick; Valiente Moro, Claire <br/> <br/>Résumé: The presence of cultivable bacteria Acinetobacter and Asaia was recently demonstrated in the mosquito vector Aedes albopictus. However, it is not known how prevalent these bacteria are in field populations. Here, the presence of these bacteria in Ae. albopictus populations from Madagascar was diagnosed by amplification of 16S rRNA gene fragments. Both genera were detected at relatively high frequencies, 46% for Asaia and 74% for Acinetobacter. The prevalence of Acinetobacter correlated significantly with mosquito gender, and the prevalence of Asaia with the interaction between mosquito gender and the sampling site. For each bacterial genus, more male than female mosquitoes were infected. Using pulse field gel electrophoresis, no significant difference in genome size was found between Acinetobacter isolates from mosquitoes compared with free-living Acinetobacter. However, a great diversity was observed in plasmid numbers (from 1 to 12) and sizes (from < 8 to 690 kb). Mosquito isolates utilized fewer substrates than free-living isolates, but some substrates known as blood or plant components were specifically utilized by mosquito isolates. Therefore it is likely that a specific subpopulation of Acinetobacter is selected by Ae. albopictus. Overall, this study emphasizes the need to gain a global view on the bacterial partners in mosquito vectors Thu, 23 May 2013 06:42:45 GMT http://hdl.handle.net/2268/148940 Titre: Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar. <br/> <br/>Auteur, co-auteur: Raharimalala, Fara Nantenaina; Raveloson Ravaomanarivo, Lala Harivelo; Ravelonandro, Pierre; Rafarasoa, Lala Sahondra; Zouache, Karima; Van, Tran Van; Mousson, Laurence; Failloux, Anna-Bella; Hellard, Eléonore; Valiente-Moro, Claire; Ralisoa Randrianasolo, Bakoly Olga; Mavingui, Patrick <br/> <br/>Résumé: Background: In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods: The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results: The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found inman-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p < 2.2 × 10-16) and period (F = 36.22, p = 2.548 × 10-13), that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. Conclusion: In Madagascar, Ae. albopictus has extended its geographical distribution whereas, Ae. aegypti has become rare, contrasting with what was previously observed. Changes are predominantly driven by human activities and the rainfall regime that provide suitable breeding sites for the highly anthropophilic mosquito Ae. albopictus. Moreover, these populations were found to be highly susceptible to chikungunya virus. In the light of this study, Ae. albopictus may have been involved in the recent outbreaks of chikungunya and dengue epidemics in Madagascar, and consequently, control measures should be promoted to limit its current expansion. Thu, 23 May 2013 06:42:29 GMT http://hdl.handle.net/2268/148936 Titre: Bacterial diversity of field-caught mosquitoes, Aedes albopictus and Aedes aegypti, from different geographic regions of Madagascar. <br/> <br/>Auteur, co-auteur: Zouache, Karima; Raharimalala, Fara Nantenaina; Raquin, Vincent; Van, Tran Van; Raveloson Ravaomanarivo, Lala Harivelo; Ravelonandro, Pierre; Mavingui, Patrick <br/> <br/>Résumé: Symbiotic bacteria are known to play important roles in the biology of insects, but the current knowledge of bacterial communities associated with mosquitoes is very limited and consequently their contribution to host behaviors is mostly unknown. In this study, we explored the composition and diversity of mosquito-associated bacteria in relation with mosquitoes’ habitats. Wild Aedes albopictus and Aedes aegypti were collected in three different geographic regions of Madagascar. Culturing methods and denaturing gradient gel electrophoresis (DGGE) and sequencing of the rrs amplicons revealed that Proteobacteria and Firmicutes were the major phyla. Isolated bacterial genera were dominated by Bacillus, followed by Acinetobacter, Agrobacterium and Enterobacter. Common DGGE bands belonged to Acinetobacter, Asaia, Delftia, Pseudomonas, Enterobacteriaceae and an uncultured Gammaproteobacterium. Double infection by maternally inherited Wolbachia pipientis prevailed in 98% of males (n = 272) and 99% of females (n = 413); few individuals were found to be monoinfected withWolbachia wAlbB strain. Bacterial diversity (Shannon–Weaver and Simpson indices) differed significantly per habitat whereas evenness (Pielou index) was similar. Overall, the bacterial composition and diversity were influenced both by the sex of individuals and by the environment inhabited by the mosquitoes; the latter might be related to both the vegetation and the animal host populations that Aedes used as food sources. Thu, 23 May 2013 06:41:35 GMT http://hdl.handle.net/2268/148524 Titre: Diversité de l’abeille & sélection de souches tolérantes à Varroa destructor <br/> <br/>Auteur, co-auteur: Leclercq, Gil; Francis, Frédéric; Haubruge, Eric; Gengler, Nicolas; Nguyen, Bach Kim <br/> <br/>Résumé: Présentation des 2 volets de recherche du projet "Selapis" (D31-1280) : la diversité de l'abeille et la sélection de souches tolérantes au Varroa Wed, 15 May 2013 13:39:17 GMT http://hdl.handle.net/2268/148522 Titre: La mortalité de l'abeille domestique : entre communication médiatique et scientifique <br/> <br/>Auteur, co-auteur: Leclercq, Gil; Francis, Frédéric; Haubruge, Eric; Gengler, Nicolas; Nguyen, Bach Kim <br/> <br/>Résumé: A l’heure actuelle, plus personne n’ignore que nos populations d’abeilles domestiques subissent de lourdes pertes, chez nous comme dans de nombreux autres pays. Les médias ont axés leur communication sur des messages très simples. On en retient surtout que les pesticides tuent nos abeilles. La conclusion au problème est dès lors évidente : il faut interdire les pesticides. Mais cette problématique est-elle si simple ? Ce message est-il le même que celui communiqué par les scientifiques ? Cette conférence permettra de faire le point sur les pertes en colonies d’abeilles domestiques. On s’intéressera plus particulièrement aux pertes de ces dernières années en Belgique, cartes et chiffres à l’appui. On y verra aussi comment chacun, qu’il soit citoyen, apiculteur, agriculteur,… peut aider à enrayer cette mortalité effrayante. Wed, 15 May 2013 13:12:10 GMT http://hdl.handle.net/2268/148265 Titre: Een nieuwe verspreidingsatlas van de loopkevers en zandloopkevers (Carabidae) in België. <br/> <br/>Auteur, co-auteur: Desender, Konjev; Dekoninck, W.; Maes, Dirk; Thys, N. Sun, 12 May 2013 10:36:14 GMT http://hdl.handle.net/2268/148261 Titre: IBISCA-Panama, a large-scale study of arthropod beta-diversity and vertical stratification in a lowland rainforest: rationale, description of study sites and field methodology <br/> <br/>Auteur, co-auteur: Basset, Yves; Corbara, Bruno; Barrios, Hector; Cuenoud, Philippe; Leponce, Maurice; Aberlenc, Henri-Pierre; Bail, Johannes; Bito, Darren; Bridle, Jonathan R.; Castano-Meneses, Gabriela; Cizek, Lukas; Cornejo, Aydee; Curletti, Gianfranco; de Oliveira, E. Gama; Dejean, Alain; Delabie, Jacques H. C.; Didham, Raphael K.; Dufrêne, Marc; Fagan, Laura L.; Floren, Andreas; Frame, Dawn M.; Halle, Francis; Hardy, Oliver J.; Hernandez, Andres; Kitching, R. L.; Lewinsohn, Thomas M.; Lewis, Owen T.; Manumbor, Markus; Medianero, Enrique; Missa, Olivier; Mitchell, Andrew W.; Mogia, Martin; Novotny, Vojtech; Ødegaard, F.; Orivel, Jerome; Ozanne, Claire P. M.; Pascal, Olivier; Pinzon, Sara; Rapp, Mathieu; Ribeiro, Servio P.; Roisin, Yves; Roslin, Tomas; Roubik, David W.; Samaniego, Mirna; Schmidl, Jürgen; Sørensen, L. L.; Tishechkin, Alexey; Van Osselaer, C.; Winchester, Neville N. Sun, 12 May 2013 09:40:02 GMT http://hdl.handle.net/2268/148255 Titre: Data Fauna-Flora 1.0. Guide d’utilisation. <br/> <br/>Auteur, co-auteur: Barbier, Yvan; Rasmont, Pierre; Dufrêne, Marc; Sibert, Jean-Marie Sun, 12 May 2013 08:48:56 GMT http://hdl.handle.net/2268/148249 Titre: Spajdel Ch., Dufrêne M., Waeyenbergh M. & Lebrun Ph. 1997. Conséquences de la relation entre la Cétoine dorée (Cetonia aurata Linné, 1761) et le complexe des fourmis rousses (Formica rufa Linné, 1763 et Formica polyctena Linné, 1763) pour la définition d'une stratégie de gestion de ces espèces protégées en Wallonie. <br/> <br/>Auteur, co-auteur: Spajdel, Ch.; Dufrêne, Marc; Waeyenbergh, M.; Lebrun, Ph. Sun, 12 May 2013 08:26:55 GMT http://hdl.handle.net/2268/148246 Titre: Observations on the mites (Acarai) associated with Carabidae (Coleoptera) in Belgium. <br/> <br/>Auteur, co-auteur: Fain, A.; Noti, J.; Dufrêne, Marc Sun, 12 May 2013 08:18:39 GMT http://hdl.handle.net/2268/148245 Titre: Les banques de données biogéographiques. <br/> <br/>Auteur, co-auteur: Dufrêne, Marc Sun, 12 May 2013 08:12:23 GMT http://hdl.handle.net/2268/148244 Titre: Carabid beetles Ecology and Evolution. <br/> <br/>Editeur scientifique: Desender, Konjev; Dufrêne, Marc; Loreau, Michel; Luff, M.-L.; Maelfait, J.P. <br/> <br/>Résumé: This book covers a broad spectrum of research on the Carabidae, with emphasis on various aspects of ecology and evolution. Papers deal with individual carabid species, for example in studies on population and reproductive biology or life history in general, and with carabid communities, as in papers treating assemblages in natural habitats, or agricultural land and forests. Disciplines covered range from biogeography and faunistics, to morphology, taxonomy and phylogenetics, ecophysiology and functional ecology to population, community, conservation and landscape ecology. Sun, 12 May 2013 08:06:21 GMT http://hdl.handle.net/2268/148242 Titre: Long term dynamics of carabid beetles in Belgium : a preliminary analysis on the influence of changing climate and land use by means of a database covering more than a century. <br/> <br/>Auteur, co-auteur: Desender, Konjev; Dufrêne, Marc; Maelfait, Jean-Pierre Sun, 12 May 2013 07:15:28 GMT http://hdl.handle.net/2268/148241 Titre: Limites et avantages des données biogéographiques pour l'évolution des tendances de la dynamique de la répartition. <br/> <br/>Auteur, co-auteur: Dufrêne, Marc Sun, 12 May 2013 07:07:58 GMT http://hdl.handle.net/2268/148240 Titre: Limites et avantages des données biogéographiques pour l'évolution des tendances de la dynamique de la répartition. <br/> <br/>Auteur, co-auteur: Dufrêne, Marc Sun, 12 May 2013 07:03:39 GMT http://hdl.handle.net/2268/148239 Titre: Biogeography of small carpenter bees of North Africa and Occidental Europe. <br/> <br/>Auteur, co-auteur: Terzo, Michael; Rasmont, Pierre; Dufrêne, Marc Sun, 12 May 2013 06:57:21 GMT http://hdl.handle.net/2268/148237 Titre: Surveillance de l'état de l'environnement wallon par bioindicateurs. <br/> <br/>Auteur, co-auteur: Marchal, Didier; Dufrêne, Marc; Lebrun, Philippe; Devillers, Pierre; Sérusiaux, Emmanuël Sun, 12 May 2013 06:51:57 GMT