References of "Zimmer, Jean-Yves"
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See detailLes porcheries : réservoirs des Culicoides (Diptera: Ceratopogonidae), vecteurs des virus de la Maladie de la Langue bleue et de Schmallenberg ?
Zimmer, Jean-Yves ULg; Saegerman, Claude ULg; Martinelle, Ludovic ULg et al

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

La fièvre catarrhale ovine (FCO) est une arbovirose qui affecte les ruminants domestiques et sauvages. Depuis sa récente apparition en Europe du Nord, cette épizootie virale a engendré des pertes ... [more ▼]

La fièvre catarrhale ovine (FCO) est une arbovirose qui affecte les ruminants domestiques et sauvages. Depuis sa récente apparition en Europe du Nord, cette épizootie virale a engendré des pertes économiques considérables. Les vecteurs biologiques du virus de la FCO sont des moucherons piqueurs appartenant au genre Culicoides (Diptera : Ceratopogonidae). Plusieurs campagnes de piégeage lumineux de ces moucherons adultes ont été réalisées précédemment en Belgique au sein d’exploitations bovines et ovines, mais aucune à l’intérieur des exploitations porcines. Cette étude vise donc à évaluer, au moyen de pièges lumineux, les populations de culicoïdes éventuellement présentes à l’intérieur de deux porcheries belges au cours de l’automne et de l’hiver 2008. La présence des espèces (potentiellement) vectrices du genre Culicoides a ainsi été mise en évidence à l’intérieur de ces bâtiments durant l’automne : 8 et 749 spécimens appartenant à 2 et 7 espèces ont ainsi respectivement été piégés au sein des porcheries, avec une majorité de femelles du complexe Obsoletus. L’ouverture des bâtiments semble fortement influencer leur présence. L’observation du statut alimentaire des femelles laisse supposer que ces moucherons sont susceptibles de se nourrir ou de pondre au sein des porcheries, même si le sang de porc n’a pas pu être identifié dans l’abdomen des femelles gorgées et que le lisier n’a pas révélé la présence de larves. Les porcs pourraient ainsi intervenir dans le maintien des populations d’espèces potentiellement vectrices du virus de la FCO, ou du nouveau virus dénommé virus Schmallenberg. [less ▲]

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See detailLa lutte contre les moustiques (Diptera: Culicidae): diversité des approches et application du contrôle biologique
Bawin, Thomas ULg; Seye, Fawrou; Boukraa, Slimane ULg et al

in Canadian Entomologist (2014)

Many mosquito (Diptera: Culicidae) species are zoonotic vectors responsible for numerous infectious diseases of medical and veterinary importance. Currently, changes in the vectors’ geographical ... [more ▼]

Many mosquito (Diptera: Culicidae) species are zoonotic vectors responsible for numerous infectious diseases of medical and veterinary importance. Currently, changes in the vectors’ geographical distribution induced chiefly by anthropogenic factors are accompanied by emerging and reemerging infectious diseases in Europe and North America. Since the advent of synthetic insecticides during the Second World War, mosquitoes are the object of considerably expanded and deepened research. In an integrated pest management context, means of control are now mainly classified as: (1) environmental management and physical control, (2) chemical control, (3) genetic control, and (4) biological control by means of entomophagous predators and entomopathogenic microorganisms. In this context, these last have significant potential because of their ability to infect and kill their host with more or less targeted selectivity. This article proposes to emphasize biological control among other techniques in mosquito control, and to assess the potential and the opportunities offered by entomopathogenic bacteria, viruses and fungi. Finally, their use as biopesticides is discussed. [less ▲]

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See detailLarval development sites of the main Culicoides species (Diptera: Ceratopogonidae) in northern Europe and distribution of coprophilic species larvae in Belgian pastures
Zimmer, Jean-Yves ULg; Brostaux, Yves ULg; Haubruge, Eric ULg et al

in Veterinary Parasitology (2014), 205(3-4), 676-686

Some Culicoides species of biting midges (Diptera: Ceratopogonidae) are biological virus vectors worldwide and have indeed been associated with outbreaks of important epizoonoses in recent years, such as ... [more ▼]

Some Culicoides species of biting midges (Diptera: Ceratopogonidae) are biological virus vectors worldwide and have indeed been associated with outbreaks of important epizoonoses in recent years, such as bluetongue and Schmallenberg disease in northern Europe. These diseases, which affect domestic and wild ruminants, have caused considerable economic losses. Knowledge of substrates suitable for Culicoides larval development is important, particularly for the main vector temperate species. This study, realized during two years, aimed to highlight the larval development sites of these biting midge species in the immediate surroundings of ten Belgian cattle farms. Moreover, spatial distribution of the coprophilic Culicoides larvae (C. chiopterus and C. dewulfi) within pastures was studied with increasing distance from farms along linear transects (farm–pasture–woodland). A total of 4347 adult specimens belonging to 13 Culicoides species were obtained by incubation of 2131 soil samples belonging to 102 different substrates; 18 of these substrates were suitable for larval development. The Obsoletus complex (formed by two species) was observed in a wide range of substrates, including silage residues, components of a chicken coop, dung adhering to walls inside stables, leftover feed along the feed bunk, a compost pile of sugar beet residues, soil of a livestock trampling area, and decaying wood, while the following served as substrates for the other specimens: C. chiopterus, mainly cow dung; C. dewulfi, cow dung and molehill soil; C. circumscriptus, algae; C. festivipennis, algae and soil in stagnant water; C. nubeculosus, algae and silt specifically from the edge of a pond; C. punctatus, mainly wet soil between silage reserves; C. salinarius, algae; and C. stigma, algae and wet soil between silage reserves. We also recorded significantly higher densities of coprophilic larvae within pastures in cow dung located near forests, which is likely due to the localization of potential hosts; the presence of these larvae within cow dung is, however, uninfluenced by relative distance from farms. A better knowledge of the microhabitats of Culicoides biting midges and their spatial distribution may allow the development of targeted species-specific vector control strategies, and may help to prevent the creation of new larval development sites. [less ▲]

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See detailPathogenicity of Aspergillus clavatus produced in a fungal biofilm bioreactor toward Culex quinquefasciatus (Diptera: Culicidae)
Seye, Fawrou; Bawin, Thomas ULg; Boukraa, Slimane ULg et al

in Journal of Pesticide Science (2014), 39(3), 127-132

Many entomopathogenic fungi have been demonstrated to be potential agents for efficiently controlling mosquito populations. In the present study, we investigated a bioreactor system to produce metabolites ... [more ▼]

Many entomopathogenic fungi have been demonstrated to be potential agents for efficiently controlling mosquito populations. In the present study, we investigated a bioreactor system to produce metabolites and conidia by combining technological advantages of submerged and solid-state fermentations. The efficiency of fungal products was tested toward mosquitoes. Aspergillus clavatus (Eurotiales: Trichocomaceae) was grown by semi-solid-state fermentation in a bioreactor for up to 7 days. Depending on conidial doses (2.5×10^7, 5×10^7, 7.5×10^7, 10×10^7 and 12.5×10^7 conidia/mL), mortality ranged from 37.2±15.0 to 86.3±5.0% toward larvae and from 35.8±2.0 to 85.2±1.5% toward adults. The metabolites (10, 20, 40, 60, 80 and 100% v/v) yielded mortality from 23.7±15.0 to 100.0±0.1% toward larvae, and two sprayed volumes (5 and 10 mL) reached 45.5±1.4 and 75.6±2.6% mortality, respectively, toward adults. [less ▲]

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See detailMolecular detection of six high importance endosymbiotic bacteria in Belgian wild-caught mosquitoes
Raharimalala, Fara Nantenaina ULg; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

Poster (2014, July)

Introduction Several disease vectors presented a resistance to various pesticides currently used. One of an alternative solution was to use endosymbiotic bacteria because their probably interactive ... [more ▼]

Introduction Several disease vectors presented a resistance to various pesticides currently used. One of an alternative solution was to use endosymbiotic bacteria because their probably interactive effects with their host. According to the introduction risks of mosquito born disease and their dispersion, we propose to investigate the prevalence of six endosymbiontic bacteria in wild-caught Culicidae in Belgium. Methods Eleven species of Belgian fields mosquitoes (Culex pipiens s.l., Cx. torrentium, Cx. hortensis, Anopheles claviger, An. maculipennis s.l., An. plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Oc. dorsalis, Aedes albopictus and Coquillettidia richiardii) were used for the screening of six genera endosymbiotic bacteria (Wolbachia sp., Commamonas sp., Delftia sp., Pseudomonas sp., Acinetobacter sp. and Asaia sp.) according to their possible impact in mosquito biology. PCR was done for the screening and positives bands were sequenced and deposited in GenBank. Results Total of 144 larvae and 32 adults were used. Wolbachia, Pseudomonas, Acinetobacter and Asaia were found in mosquitoes with different proportions, according to stages (adults, larvae) with a predominance of Pseudomonas in all species, as far as Acinetobacter and Asaia also have a high prevalence. Commamonas and Delftia were absent from all species tested, either in larvae and in adults. Discussion Choice of endosymbiotic bacteria studied here was allowing of their importance in literature. For Pseudomonas, it showed that this bacteria could produced ovipositon attractants for mosquito. Acinetobacter was suggested efficient in transmission and maintenance within host populations. Asaia was capable of efficiently crossing body barriers and colonizing different organs. Wolbachia was currently the most studied bacteria which plays an important role in the genetic manipulation of the host. Present advances in understanding the mosquito–microbiota relationships may have a great impact in a better understanding of some traits of mosquito biology and in the development of innovative mosquito-borne disease-control strategies. [less ▲]

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See detailEffect of entomopathogenic Aspergillus strains against the pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae)
Seye, Fawrou; Bawin, Thomas ULg; Boukraa, Slimane ULg et al

in Applied Entomology and Zoology (2014)

Aphids (Homoptera: Aphididae) are sap-sucking insect pests that feed on several plants of agronomical importance. Entomopathogenic fungi are valuable tools for potential aphid control. As part of a ... [more ▼]

Aphids (Homoptera: Aphididae) are sap-sucking insect pests that feed on several plants of agronomical importance. Entomopathogenic fungi are valuable tools for potential aphid control. As part of a selection process, laboratory bioassays were carried with five different concentrations of Aspergillus clavatus (Desmazières), Aspergillus flavus (Link) and Metarhizium anisopliae ((Metschnikoff) Sorokin) spores against the pea aphid, Acyrthosiphon pisum (Harris). Aspergillus isolates induced higher mortalities than M. anisopliae which is a well-known entomopathogen in the literature. Lethal concentrations (LC50 and LC90) were 1.23 x 10^3 and 1.34 x 10^7 spores/ml for A. flavus, 4.95 x 10^2 and 5.65 x 10^7 spores/ml for A. clavatus, and 3.67 x 10^3 and 9.71 x 10^7 spores/ml for M. anisopliae five days after treatment. Mycelia development and sporulation on adult cadavers was observed 48 hours after incubation. The intrinsic growth rate of A. pisum decreased with increased spore concentration for all fungal strains suggesting an increase in pathogen fitness related to a consumption of host resources. In conclusion, Aspergillus species could be useful in aphid control as pest control agents despite their saprophytic lifestyle. This is also in our knowledge the first report of A. clavatus and A. flavus strains pathogenic to aphids. [less ▲]

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See detailSynthèse bibliographique : l'écologie larvaire des culicoïdes (Diptera : Ceratopogonidae)
Zimmer, Jean-Yves ULg; Haubruge, Eric ULg; Francis, Frédéric ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(2), 301-312

Cet article présente une synthèse de l’écologie larvaire des culicoïdes (Diptera : Ceratopogonidae) en vue de rassembler les connaissances, souvent très parsemées, des sites d’oviposition et des habitats ... [more ▼]

Cet article présente une synthèse de l’écologie larvaire des culicoïdes (Diptera : Ceratopogonidae) en vue de rassembler les connaissances, souvent très parsemées, des sites d’oviposition et des habitats larvaires actuellement identifiés à travers le monde pour les principales espèces de culicoïdes. Ces moucherons piqueurs hématophages sont impliqués dans la transmission de divers parasites (protozoaires et filaires) et virus aux animaux. Le développement larvaire des culicoïdes est généralement optimal dans les substrats humides et riches en débris organiques divers. Cependant, chaque espèce présente ses propres exigences écologiques et se trouve par conséquent dans des micro-habitats spécifiques. Dans cette synthèse, les gites larvaires sont répartis en substrats aquatiques et semi-aquatiques d’eau douce et d’eau salée ou saumâtre, substrats terrestres et substrats anthropiques liés à l’élevage. Les gites larvaires de nombreuses espèces appartenant au genre Culicoides Latreille demeurent cependant encore méconnus. La connaissance de ces derniers et leur caractérisation sont pourtant essentielles pour permettre la mise au point de stratégies de lutte efficaces contre ces insectes vecteurs, permettant ainsi de renforcer la vaccination du bétail et les autres moyens de lutte mis en oeuvre. Les habitats larvaires actuellement identifiés pourraient permettre d’orienter les investigations des recherches écologiques futures et les propositions de contrôle de ces moucherons vecteurs. [less ▲]

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See detailÉtude des Culicoides Latreille (Diptera: Ceratopogonidae) vecteurs d'agents pathogènes: état des lieux des espèces belges, de leurs micro-habitats larvaires et de leurs préférences trophiques
Zimmer, Jean-Yves ULg

Doctoral thesis (2014)

Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are the biological vectors of many recently described pathogens in Northern Europe, including the Bluetongue and Schmallenberg viruses ... [more ▼]

Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are the biological vectors of many recently described pathogens in Northern Europe, including the Bluetongue and Schmallenberg viruses. These arboviral diseases have led to considerable economic loss in sheep and cattle livestock. However, many uncertainties remain regarding the distribution, biology, and ecology of these vectors. This research project had three main objectives. The first objective was to conduct an inventory of the different Culicoides species on different Belgian farms and on wetlands, using light traps. Many more Culicoides were caught in the vicinity of buildings than in meadows; this finding seemed to be influenced by the density of hosts near the trap and the opening of buildings. The Obsoletus complex was predominant inside buildings and in the meadows of farms; however, the meadows exhibited greater species diversity. The oligotrophic species C. impunctatus, a potential vector of several pathogens, was particularly abundant in peat bogs. The traps that were used herein enabled the identification of three species that have not previously been reported in Belgium, bringing the total number of Belgian species to 52. The second objective was to identify and characterize larval microhabitats of the main Belgian species of Culicoides, and to study the distribution of coprophilous species (C. chiopterus and C. dewulfi) in meadows. Ten Belgian cattle farms were monitored for two consecutive years, and sixteen substrates conducive to the larval development of these biting midges were identified. The most significant finding was that different types of silage residues (e.g., corn, grass, beet pulp, and their combinations) were favourable to the larvae of the two species that compose the Obsoletus complex. A larval microhabitat that is appropriate to these two species was also identified, for the first time, directly inside a barn: specifically, within the dried dung stuck to the barn walls and resulting from the partial removal of used litter. Therefore, Culicoides could complete their life cycle in the vicinity of the stables, which might explain the persistence of the virus from one year to the next despite harsh winters. Influences of the carbon-to-nitrogen ratio, lignin, insoluble fibre, magnesium, and calcium on the presence of larvae were also examined. The third objective was to study the feeding preferences of the species C. obsoletus. This species is prevalent on Belgian farms and has considerable medical and veterinary relevance. Behavioural analyses were performed under field and laboratory conditions, respectively through a flight tunnel containing potential hosts (human, calf, sheep and chicken) and a two-choice olfactometer containing volatile extracts of host skin. The field experiment revealed the preference of C. obsoletus females for large hosts, probably caused by greater emission of carbon dioxide. In contrast, these midges were more attracted to volatile organic compounds released from the skin surface of chicken and sheep during the laboratory experiment. This study contributed to improve the fundamental knowledge of Palaearctic species of the genus Culicoides, and highlighted promising avenues to control these biting midges. Knowledge of the breeding sites of Culicoides could thus allow substrates to be monitored and control or hygiene measures to be implemented, while preventing new sites from being created. A better understanding of the vector-host interactions may aid in developing new strategies to control adult midges, while improving understanding of the pathogen transmission cycle and the epidemiology of associated diseases. [less ▲]

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See detailPhylogenetic study of Aedes albopictus and Aedes koreicus (Diptera, Culicidae) origin, two invasive mosquito species in Belgium
Raharimalala, Fara Nantenaina ULg; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

Poster (2014, April 10)

The main ways of the introduction of invasive mosquito species in Europe were greatly facilitated by the importation of used tires and plants from the South of China (Dracaena sanderiana, called "Lucky ... [more ▼]

The main ways of the introduction of invasive mosquito species in Europe were greatly facilitated by the importation of used tires and plants from the South of China (Dracaena sanderiana, called "Lucky bamboo"), which are a very good breeding sites of these mosquitoes (www.eidatlantique.eu). For Belgium, several species of exotic mosquitoes have already been listed such as Ochlerotatus japonicus japonicus, Aedes albopictus and A. koreicus. We have captured one male of A. albopictus in Belgium in July 2013 (Boukraa et al, 2013), and teams from other entomologist have been able to find several individuals in the months that have followed our discovery (personal communication). However, his presence was reported first in 2000 (Schaffner et al. 2004) but until 2012, no individuals have been found (Versteirt et al., 2013). We also could find larvae of A. koreicus in abundance. These discovery suggest that these two invasive species are being established in Belgium. Methods: Adult mosquitoes were collected by CO2-baited traps Mosquito Magnet Liberty Plus (MMLP) and immature stages by the dipping method from 8 sites of Belgium. Each individual was then determined morphologically. For A. albopictus and A. koreicus, reconfirmation by molecular method was performed with COI and ND5 mitochondrial primers and sequences were then aligned with those of mosquitoes available in databases by using BioEdit and Multialn softwares. The two gene sequences were concatenated to improve the reliability of the phylogenetic analysis and were carried out by using the Seaview software based on maximum likelihood (ML) methods. Trees were then constructed with the general time reversible (GTR) model, and branch supports were estimated by bootstrapping with 1000 replicates. Result: The aim of this work will focus on the study of the probable origin of these two species of Aedes, which are for the moment safe yet, but that might become dangerous in the event of massive outbreak. The knowledge of the probably origin of the two invasive mosquitoes allow take more protection against their way to enter in the country. [less ▲]

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See detailBiofilms from entomopathogenic fungi in mosquito control
Bawin, Thomas ULg; Boukraa, Slimane; Seye, Fawrou et al

Poster (2014, February 07)

Mosquitoes (Diptera: Culicidae) are zoonotic vectors of medical and veterinary importance. As part of an integrated vector control, metabolites secreted by entomopathogenic fungi could be developed as ... [more ▼]

Mosquitoes (Diptera: Culicidae) are zoonotic vectors of medical and veterinary importance. As part of an integrated vector control, metabolites secreted by entomopathogenic fungi could be developed as biopesticides. In this context, filamentous microorganisms growing on a support as biofilm in a liquid medium would offer several advantages in bioreactor regarding performances and metabolites recovery. The production of toxic metabolites by an entomopathogenic fungus Aspergillus flavus in such conditions was assessed. Three initial inoculum levels, i.e. 10^1, 10^3 and 10^6 spores/ml of PYG medium, have been tested in shake flask with or without support. Toxicity tests were performed on Culex quinquefasciatus larvae using dilutions of 1, 2, 4, 6, 8 and 10% of liquid cultures. The results indicated that A. flavus tends to form pellets in submerged culture; the size and the amount of pellets was affected by the initial inoculum level of spores. Under similar conditions, the filaments fixed on a support and didn’t appear in free form in the liquid. Toxicity tests revealed differences between both free and fixed forms. All combined conditions, LC50s ranging up to dilutions of 2.2 and 4.8% were observed within 48 hours. Secretomes could be compared between these culture conditions by proteomic and metabolomic approaches. [less ▲]

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See detailUsing micro-injection technique to assess fungal toxicity in mosquito control
Bawin, Thomas ULg; Boukraa, Slimane; Seye, Fawrou et al

in Communications in Agricultural and Applied Biological Sciences (2014, February 07), 79(1), 181-185

Topical application of insecticidal compounds allows directly exposing these substances on insect tissues and measuring their toxicity while ignoring many factors. However, this technique remains ... [more ▼]

Topical application of insecticidal compounds allows directly exposing these substances on insect tissues and measuring their toxicity while ignoring many factors. However, this technique remains difficult to apply on mosquito larvae considering their aquatic lifestyle. Micro-injection could be used for the direct deposition of toxic compounds in the larvae. Capillaries exhibiting an injection tip with an external diameter of 0.5 mm have been designed from silica tubes. For each treatment, a capillary is mounted on a pump connected to a flow rate regulator. Culex quinquefasciatus larvae were injected with 10^7 spores/ml of entomopathogenic fungi (Aspergillus clavatus, Metarhizium anisopliae, Metarhizium sp.). Mortalities were recorded daily during 72h. The distribution of spores stained with methylene blue and injected into the body of larvae was also observed according to the system described. Results showed that spores were distributed over the whole body. The injection of Aspergillus clavatus, Metarhizium anisopliae and Metarhizium sp spores induced corrected mortalities of 62%, 53% and 57% after 72h, and differed statistically from control groups. Finally, post-mortem emergences of filaments from dead larvae were observed in the case of the three fungal strains confirming spore viability. Injection of inactivated spores (or inert bodies of similar size) could help to reject the hypothesis of a response due to the presence of foreign bodies. [less ▲]

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See detailReintroduction of the invasive mosquito species Aedes albopictus in Belgium in July 2013
Boukraa, Slimane ULg; Raharimalala, Fara Nantenaina ULg; Zimmer, Jean-Yves ULg et al

in Parasite (Paris, France) (2013), 20(54),

Since its first report in 2000, the invasive mosquito Aedes albopictus was not found any more during the different entomological inspections performed at its place of introduction in Belgium between 2001 ... [more ▼]

Since its first report in 2000, the invasive mosquito Aedes albopictus was not found any more during the different entomological inspections performed at its place of introduction in Belgium between 2001 and 2012. In July 2013, one adult male was captured at the same site (a platform of imported used tires located in Vrasene, Oost-Vlaanderen Province), during a monitoring using CO2-baited trap. This finding suggests the reintroduction of the species in Belgium via the used tire trade. [less ▲]

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See detailComparaison des populations de Culicoides Latreille 1809 (Diptera: Ceratopogonidae) présentes au sein d’une bergerie belge et d’une prairie ovine associée
Zimmer, Jean-Yves ULg; Losson, Bertrand ULg; Saegerman, Claude et al

in Annales de la Société Entomologique de France (2013), 49(4), 446-459

Culicoides biting midges (Diptera: Ceratopogonidae) serve as biological vectors for several pathogens, including the Bluetongue virus and the recently described Schmallenberg virus in northern Europe ... [more ▼]

Culicoides biting midges (Diptera: Ceratopogonidae) serve as biological vectors for several pathogens, including the Bluetongue virus and the recently described Schmallenberg virus in northern Europe. These diseases have caused considerable direct and indirect economic losses to the sheep and cattle industries. This study undertaken between August and December 2007 on a sheep farm in the Namur province (Belgium) aims to evaluate Culicoides populations present inside a partially opened sheepfold and in a nearby sheep meadow, using light traps. The comparative analysis of insects trapped at 18 dates at regular intervals showed that Culicoides were most abundant Inside this livestock building (17,450 midges) than in surrounding meadow (1,121 midges); this meadow had however a greater species diversity. The two species C. obsoletus and C. scoticus constituting the Obsoletus complex predominated for all trappings and females were much more numerous than males. Important capture of engorged females of the Obsoletus complex inside the sheepfold seems to reflect the possibility of an opportunistic endophagous behavior. Maintaining sheep inside livestock buildings in order to reduce the risk of Culicoides bites – and thus of pathogens transmission – however requires to limit biting midge populations which are likely to enter or to develop inside these buildings. Implementation of effective sanitation and hygiene measures against midges present inside farms, as well as establishing of measures to protect livestock against intrusion and improvement of “midge-proofing” of animal housing are therefore highly recommended. [less ▲]

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See detailRéintroduction d'Aedes albopictus, une menace pour la Belgique? (Diptera: Culicidae)
Boukraa, Slimane ULg; Raharimalala, Fara Nantenaina ULg; Zimmer, Jean-Yves ULg et al

Conference (2013, November 23)

Actuellement, l’espèce Aedes albopictus Skuse est considérée comme le moustique le plus invasif dans le monde entier et l’un des plus importants vecteurs d’arbovirus (notamment chikungunya et dengue). En ... [more ▼]

Actuellement, l’espèce Aedes albopictus Skuse est considérée comme le moustique le plus invasif dans le monde entier et l’un des plus importants vecteurs d’arbovirus (notamment chikungunya et dengue). En Belgique, Ae. albopictus a été introduit pour la première fois en 2000 à Vrasene (Province de Flandre-Orientale), dans une entreprise de recyclage des pneus usagés en provenance des États-Unis et du Japon. Plusieurs autres inspections ont été effectuées (2001-2012) après ce premier rapport, mais aucun autre spécimen n’a été trouvé. L’espèce était considérée comme éliminée naturellement et aucune nouvelle introduction n’avait été signalée. Dans le cadre d'une étude de surveillance de moustiques réalisée dans plusieurs endroits à travers la Belgique en 2013, un adulte mâle d’Ae. albopictus a été capturé à l'aide d’un piège à CO2 à Vrasene dans la même entreprise de recyclage de pneus (51 ° 12'49 "N, 4 ° 11'37" E; juillet 2013). L’espèce a été confirmée par identification morphologique et moléculaire. Cette redécouverte d’Ae. albopictus ainsi que son absence durant les treize dernières années, démontrent sa réintroduction en Belgique via le commerce de pneus usagés. Une étude sur la survie et la dispersion de ce moustique en Belgique, ainsi que de son écologie dans les pays voisins pourrait fournir des indications importantes pour élucider davantage son caractère invasif et identifier les zones à haut risque. [less ▲]

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See detailEcology of mosquitoes (Diptera, Culicidae) potentially vectors of arboviruses according to the kinds of animal husbandry in Belgium
Boukraa, Slimane ULg; De la Grandière de Noronha Cotta, Maria Ana ULg; Bawin, Thomas ULg et al

Poster (2013, November 12)

Human activity, commercial exchanges and climate changes current and future, could favor the (re)-emergence of vector-borne diseases, by inducing changes on Culicidae populations. This study aims to ... [more ▼]

Human activity, commercial exchanges and climate changes current and future, could favor the (re)-emergence of vector-borne diseases, by inducing changes on Culicidae populations. This study aims to determine the potential importance of agricultural environments, especially cattle farms and equestrian, to welcome and favor the proliferation of some species of mosquito responsible for transmission of arboviruses. To better understand the structure of the Culicidae population and identify habitats favorable to the development of each species, a taxonomic inventory was conducted in 2008 (III, VI and X) and 2009 (V and IX) in ten cattle farms, and in 2011 (VI-X) and 2012 (VI-IX) in six equestrian farms located in Belgium. The harvest of mosquitoes is based on adult trapping by CO2-traps (Mosquito magnet) and on larval sampling at the level of 64 biotopes such as water troughs, used tires, abandoned utensils and temporary puddles or not. The morphotaxonomic of larvae and genitalia, and molecular study showed the presence of 15 species: Culiseta annulata Schrank, 1776; Cs. morsitans Theobald, 1901 Anopheles claviger s.s. Meigen, 1804; An. maculipennis s.s. Meigen, 1818; An. messeae Falleroni, 1926; An. plumbeus Stephens, 1828; Culex pipiens molestus Forskal, 1775; Cx. pipiens pipiens L., 1758; Cx. torrentium Martini, 1925; Cx. hortensis hortensis Ficalbi, 1889; Cx. territans Walker, 1856; Coquillettidia richiardii Ficalbi, 1889; Ochlerotatus geniculatus Olivier, 1791; Oc. cantans Meigen, 1818 and Aedes cinereus Meigen, 1818. Among the 57,680 individuals examined, Cx. pipiens s.l., Cx. torrentium and Cs. annulata are the dominants species and ubiquitous in all farms visited. The species of the genus Anopheles have strong ecological requirements and are therefore associated with some special habitats; other species however have a strong ability to adapt and therefore attend a wide variety of biotopes (Cx. pipiens s.l., Cx. torrentium and Cs. annulata). Water troughs, used tires and ponds are the most favorable habitats for larval development of Culicidae. The species potentially vectors of arboviruses that can cause problems in epidemiological farms are Cx. pipiens s.l., Cx. torrentium and Cq. richiardii. Therefore, despite the low diversity of mosquito observed within the livestock environments, they represent a significant risk for the reproduction of some potential vectors of arboviruses. In addition, some larval habitats constitute very favorable sites for proliferation of mosquito, causing a real problem of nuisance for animals of farms. [less ▲]

Detailed reference viewed: 47 (21 ULg)
See detailImportation récente d’Aedes albopictus en Belgique : modes d’introduction, risques et gestion des risques
Boukraa, Slimane ULg; Raharimalala, Fara Nantenaina ULg; Zimmer, Jean-Yves ULg et al

Conference (2013, October 25)

L'environnement et les changements climatiques, ainsi que la mondialisation des échanges commerciaux internationaux peuvent affecter la distribution des pathogènes et/ou des arthropodes vecteurs ... [more ▼]

L'environnement et les changements climatiques, ainsi que la mondialisation des échanges commerciaux internationaux peuvent affecter la distribution des pathogènes et/ou des arthropodes vecteurs. Actuellement, l’espèce Aedes albopictus Skuse est considérée comme le moustique le plus invasif dans le monde entier et l’un des plus importants vecteurs d’arbovirus (notamment chikungunya et dengue). En Belgique, Ae. albopictus a été introduit pour la première fois en 2000 à Vrasene (Province de Flandre-Orientale), dans une entreprise de recyclage des pneus usagés en provenance des États-Unis et du Japon. Plusieurs autres inspections ont été effectuées (2001-2012) après ce premier rapport, mais aucun autre spécimen n’a été trouvé. L’espèce était considérée comme éliminée naturellement et aucune nouvelle introduction n’avait été signalée. Dans le cadre d'une étude de surveillance de moustiques réalisée dans plusieurs endroits à travers la Belgique en 2013, un adulte mâle d’Ae. albopictus a été capturé à l'aide d’un piège à CO2 à Vrasene dans la même entreprise de recyclage de pneus (51°12'49" N, 4°11'37" E; juillet 2013). L’espèce a été confirmée par identification morphologique et moléculaire. Cette redécouverte d’Ae. albopictus ainsi que son absence durant les treize dernières années, démontrent sa réintroduction en Belgique via le commerce de pneus usagés. Une étude sur la survie et la dispersion de ce moustique en Belgique, ainsi que de son écologie dans les pays voisins pourrait fournir des indications importantes pour élucider davantage son caractère invasif et identifier les zones à haut risque. Contexte Aedes albopictus (Skuse, 1894) (Diptera: Culicidae), communément appelé « le moustique tigre », est une espèce invasive originaire d’Asie du Sud-Est. Une nouvelle réintroduction de ce vecteur d’arbovirus a été enregistré en été 2013 en Belgique. Cette présentation abordera successivement : (a) L’invasion d’Ae. albopictus et importance médicale, (b) (Ré)-Introduction d’Ae. albopictus en Belgique, (c) Risque lié à l’introduction et à l’adaptation d’Ae. albopictus en Belgique, (d) Gestion de risque et contrôle. a. Invasion d’Ae. albopictus et importance médicale Depuis la fin des années 70s, Ae. albopictus connait une propagation explosive dans le monde entier où il est considéré actuellement comme le moustique le plus invasif dans le monde (1). La mondialisation des échanges commerciaux, notamment les pneus usagés (2) et le Lucky Bambou (3), est un facteur clé de cette invasion. En Europe, il a été signalé dans 20 pays et est aujourd'hui bien installé dans la région méditerranéenne (1). Ae. albopictus fait partie des plus importants vecteurs d’arbovirus, en particulier pour les virus de la dengue et du chikungunya (1), et des filarioses animales notamment Dirofilaria spp. (4). Le risque d'apparition et la propagation de ces arbovirus aux régions non épidémiques ont surtout augmenté dans les régions où Ae. albopictus est établi. Cette hypothèse est démontrée à plusieurs reprises, notamment les récentes transmissions autochtones du chikungunya et de la dengue en Italie, en Croatie et en France (1). b. (Ré)-Introduction d’Ae. albopictus en Belgique En Belgique, Ae. albopictus a été introduit pour la première fois en 2000 à Vrasene (Province de Flandre-Orientale), dans une entreprise de recyclage des pneus usagés en provenance des États-Unis et du Japon (5). Plusieurs autres inspections ont été effectuées (2001-2012) après ce premier rapport, mais aucun autre spécimen n’a été trouvé (6, Schaffner données non publiées). L’espèce était considérée comme éliminée naturellement et aucune nouvelle introduction n’avait été signalée (6). Cependant, une étude sur la surveillance de moustiques réalisée dans plusieurs endroits à travers la Belgique en 2013 a de nouveau signalé la capture d’Ae. albopictus à Vrasene, dans la même entreprise de recyclage de pneus. Cette redécouverte d’Ae. albopictus, ainsi que l'absence de toute constatation au cours des années précédentes (2001-2012), démontre sa réintroduction en Belgique via le commerce des pneus usagés (7). c. Risque lié à l’introduction et à l’adaptation d’Ae. albopictus en Belgique Aedes albopictus est un vecteur efficace confirmé des virus de la dengue et du chikungunya (1), ainsi que des filarioses animales notamment Dirofilaria spp. (4) ; la Belgique enregistre de plus régulièrement des cas de chikungunya importés (8). Ainsi, s'il s'établit dans le pays, Ae. albopictus peut devenir une menace importante et réelle pour la santé humaine et animale tant par son rôle de vecteur d'agents pathogènes que par sa nuisance. d. Gestion de risque et contrôle Une étude sur la survie et la dispersion d’Ae. albopictus en Belgique, ainsi que sur sa bio-écologie dans les pays voisins pourrait fournir des indications importantes pour élucider davantage son caractère invasif, et identifier les zones à haut risque. Une réponse proactive rapide est essentielle pour la lutte anti-vectorielle afin d’éviter son installation en Belgique. Cela inclut la mise en œuvre rapide de mesures de contrôle, avant que l’élimination ne devienne impossible (9). Les programmes de surveillance et de contrôle doivent cibler davantage toutes les zones possibles d’introduction de ce vecteur, en particulier les entreprises du commerce international des pneumatiques et des plantes ornementales telle que le Lucky Bambou. Ces programmes doivent également être appliqués durant toute la saison d’activité d’Ae. albopictus, sous une logique de lutte anti-vectorielle intégrée (10). A cet effet, l’appel aux moyens de lutte mécanique et les traitements larvicides sont fortement recommandés. Le recours aux traitements adulticides cependant, sera justifié uniquement en cas d’abondance de l’espèce due à de nouvelles réintroductions. Conclusion Les réintroductions d’Ae. albopictus en Belgique via l’importation de pneus usagés, l’environnement favorable à son installation et la confirmation régulière de cas importés du chikungunyia rendent la Belgique vulnérable aux risques d’une transmission autochtone de cette maladie infectieuse. Vu que plusieurs pays d'Europe de l'Ouest connaissent actuellement des introductions répétées d'Ae. albopictus sur leurs territoires, la mobilisation et la coordination des surveillances entomologiques entre ces pays - y compris la Belgique - sont devenues plus que nécessaires afin de traquer toutes les voies potentielles de réintroductions. Compte tenu du grand pouvoir adaptatif et invasif d'Ae. albopictus, il est recommandé d’agir rapidement et efficacement pour éliminer cette espèce avant son installation et sa dissémination ; ces mesures permettraient ainsi de réduire le risque de transmission des arboviroses en Belgique. Référence 1. J. M. Medlock, K. M. Hansford, F. Schaffner, V. Versteirt, G. Hendrickx, H. Zeller, et al. A Review of the Invasive Mosquitoes in Europe: Ecology, Public Health Risks, and Control Options. Vect born Zoo Dis, 12, 435-447 (2012). 2. E. A. Gould, S. Higgs. Impact of climate change and other factors on emerging arbovirus diseases. Trans R Soc Trop Med Hyg, 103(2), 109–121 (2009). 3. E. J. Scholte, E. Dijkstra, H. Blok, A. De Vries, W. Takken, A. Hofhuis et al. Accidental importation of the mosquito Aedes albopictus into the Netherlands: a survey of mosquito distribution and the presence of dengue virus. Med Vet Entomol, 22, 352-358 (2008). 4. G. Cancrini, P. Scaramozzino, S. Gabriella, M. Di Paolo, L. Toma, R. Romi. Aedes albopictus and Culex pipiens implicated as natural vectors of Dirofilaria repens in central Italy. J Med Entomol, 44, 1064–1066 (2007). 5. F. Schaffner, W. Van Bortel, M. Coosemans. First record of Aedes (Stegomya) albopictus in Belgium. J Am Mosq Cont Assoc 20, 201-203 (2004). 6. V. Versteirt, S. Boyer, D. Damiens, E. M. De Clercq, W. Dekoninck, E. Ducheyne et al. Nationwide inventory of mosquito biodiversity (Diptera: Culicidae) in Belgium. Europe Bull Entomol Res 103, 193-203 (2013). 7. S. Boukraa, F. N. Raharimalala, J.-Y. Zimmer, F. Schaffner, T. Bawin, E. Haubruge, et al. Rediscovery of Aedes albopictus in Belgium: introduction or establishment ? Emerg Infect Dis, (Article soumis) (Septembre, 2013) 8. E. Bottieau, M. Van Esbroeck, L. Cnops, J. Clerinx, A. Van Gompel. Chikungunya infection confirmed in a Belgian traveller returning from Phuket (Thailand). Euro Surveill, 14, 1-2 (2009). 9. F. Schaffner, R. Bellini, D. Petrić, E.-J. Scholte, H. Zeller, L. Marrama Rakotoarivony. Development of guidelines for the surveillance of invasive mosquitoes in Europe. Parasit Vectors, 6, 209 (2013). 10. Centre national d’Expertise sur les Vecteurs. Introduction d’arthropodes vecteurs au niveau des plateformes portuaires et aéroportuaires. Identification des principaux risques (2012). [less ▲]

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Peer Reviewed
See detailBacterial diversity of field-caught mosquitoes from different regions of Belgium and potential impact on virus transmission
Raharimalala, Fara Nantenaina ULg; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

Poster (2013, October 02)

Several vectors disease presented a resistance to various pesticides currently used. Endosymbiotic bacteria was an alternative solution found because of their probably interactive effects with their host ... [more ▼]

Several vectors disease presented a resistance to various pesticides currently used. Endosymbiotic bacteria was an alternative solution found because of their probably interactive effects with their host. According to the introduction risks of these virus and disease dispersion, we propose to investigate the bacterial endosymbiont role in Culicidae in Belgium. Among the 30 species of mosquitoes identified in this country, about ten are considered as potential vectors of arboviruses. In this study, eleven species of Culicidae belonging to five genera (Culex pipiens s.l., Cx. torrentium, Cx. hortensis, Anopheles claviger, An. maculipennis s.l., An. plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Oc. dorsalis, Aedes albopictus and Coquillettidia richiardii) mosquitoes fields from eight sites of Belgium were used for the screening of the presence of six genera endosymbiotic bacteria (Wolbachia sp, Commamonas sp, Delftia sp, Pseudomonas sp, Acinetobacter sp and Asaia sp) according their possible impact in mosquito biology. PCR was done for the screening of endosymbiotic bacteria mosquitoes studied. A total of 176 individuals (144 larvae and 32 adults) were used. Our results allowed us to confirm the absence of Wolbachia in An. clavigere, An. maculipennis s.l and Cx. torentium. Acinetobacter was found in every species. Current advances in understanding the mosquito–microbiota relationships may have a great impact in a better understanding of some traits of mosquito biology and in the development of innovative mosquito-borne disease-control strategies aimed to reduce mosquito vectorial capacity and/or inhibiting pathogen transmission. [less ▲]

Detailed reference viewed: 55 (16 ULg)
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See detailAssessment of bacterial persistence in mosquitoes according to microinjection assays in Belgium
Raharimalala, Fara Nantenaina ULg; Bawin, Thomas ULg; Boukraa, Slimane ULg et al

Poster (2013, October 02)

The problems caused by the massive used of pesticides have resulted in the establishment of resistant vectors besides the destruction of the environment. Furthermore, climate change has consequently ... [more ▼]

The problems caused by the massive used of pesticides have resulted in the establishment of resistant vectors besides the destruction of the environment. Furthermore, climate change has consequently modified the comportment of disease vectors. Current research tends to look for alternative means to overcome the problem. The goal of that study was to undertaken the way there this objective. By their presence or absence, endosymbiotic microorganisms can influence vector competence and vectorial capacity. Our research aims to study the effect of the introduction of endosymbiotic bacteria in the mosquito species that could be potential vectors of disease in Belgium. Method used was the microinjection of endosymbiotic bacteria within the detected exempt mosquito species. Three genus of suspected vectors belonging to Aedes, Anopheles and Culex were microinjected at different stages of their life cycle (eggs, larvae, pupae, and adults), and survivability of mosquitoes and persistence of microorganism were determined. Results show that survival in the different stages was variable. Furthermore, persistence of endobacteria was different depending genus and stages studied [less ▲]

Detailed reference viewed: 55 (24 ULg)