References of "Francis, Frédéric"
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See detailUtilisation des termites comme source de microorganismes dans la filière de production du bioéthanol de seconde génération
Tarayre, Cédric ULg; Bauwens, Julien ULg; Brasseur, Catherine ULg et al

Poster (2012, November 14)

Les termites abritent une microflore symbiotique qui intervient dans la dégradation des fibres constitutives du bois, synthétisant des enzymes capables d’hydrolyser ses composants. Les sucres ... [more ▼]

Les termites abritent une microflore symbiotique qui intervient dans la dégradation des fibres constitutives du bois, synthétisant des enzymes capables d’hydrolyser ses composants. Les sucres fermentescibles libérés suite à cette hydrolyse sont utilisables dans le cadre de la production du bioéthanol de seconde génération. [less ▲]

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See detailDiversité de l’abeille & sélection de souches tolérantes à Varroa destructor
Leclercq, Gil ULg; Francis, Frédéric ULg; Haubruge, Eric ULg et al

Conference given outside the academic context (2012)

Présentation des 2 volets de recherche du projet "Selapis" (D31-1280) : la diversité de l'abeille et la sélection de souches tolérantes au Varroa

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See detailDiversity and breeding sites of mosquitoes (Diptera, Culicidae) potentially vectors of arboviruses in Belgian equestrian farms
Boukraa, Slimane ULg; De la Grandière de Noronha Cotta, Maria Ana ULg; Bawin, Thomas ULg et al

Poster (2012, October 08)

This study aims to determine the potential importance of the livestock farms, especially equestrian, to welcome and favor the proliferation of certain species of mosquito responsible for transmission of ... [more ▼]

This study aims to determine the potential importance of the livestock farms, especially equestrian, to welcome and favor the proliferation of certain species of mosquito responsible for transmission of arboviruses. The study of biodiversity of Culicidae in the horse farms in Belgium is carried out on species sampled at 64 biotopes in six stations study. Five surveys were realized during 2011 (June, July, August and October) and one in 2012 (June). The morphotaxonomic and molecular study of mosquitoes collected showed the presence of ten species: Culisata annulata Schrank, 1776; Anopheles claviger s.s. Meigen, 1804; An. maculipennis s.s. Meigen, 1818; An. messae Falleroni, 1926; Culex pipiens molestus Forskal, 1775; Cx. pipiens pipiens Linné, 1758; Cx. torrentium Martini, 1925; Cx. hortensis hortensis Ficalbi, 1889; Cx. territans Walker, 1856 and Coquillettidia richardii Ficalbi, 1889. Among the 24893 individuals examined in 2011, Cx. pipiens sl and Cx. torrentium represent 68.00% and 22.38% respectively of total harvest. These last species with Cs. annulata, are dominants and ubiquitous in all the horse 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, Cx. torrentium and Cs. annulata). At the horse farms, water troughs and ponds are the most favorable habitats for larval development of Culicidae. The species potentially vectors of arboviruses that can cause problems in epidemiological equestrian farms are Cx. pipiens sl, Cx. torrentium and Cs. annulata. [less ▲]

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See detailLaboratory and field preliminary tests of Metarhizium anisopliae formulated with neem oil (Suneem) against Anopheles gambiae sl adult emergence
Seye, Fawrou; NDIONE, Raymond; Touré, Mamour et al

Poster (2012, October 08)

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See detailLaboratory and field preliminary tests of Metarhizium anisopliae formulated with neem oil (Suneem) against Anopheles gambiae sl adult emergence
Seye, Fawrou; Ndione, Raymond; Touré, Mamour et al

Poster (2012, October 08)

Metarhizium anisopliae have shown great potential for the control of malaria vectors. However, their ability to control aquatic stages of anopheline vectors with conidial formulation is need. In ... [more ▼]

Metarhizium anisopliae have shown great potential for the control of malaria vectors. However, their ability to control aquatic stages of anopheline vectors with conidial formulation is need. In laboratory condition (25°C and 76%RH), we formulated M. anisopliae with emulsifian neem oil (Suneem 1%) before application on An. gambiae larvae at 4, 6, 8, 10 and 12 % (v/v) to determine the LD90. We applied in semi-field environment, the LD90 of the formulation into artificial vats on the Anopheles gambiae sl larvae collected from many breeding sites at dry and rain seasons. In laboratory condition, the LD 50 was 4.4 x 10^6 spores/ml and the LD90 was not obtained 24 after exposure. The probite line equation was Y=1.61 x – 0.55 and R²= 0.9793. The LD 50 was 3.1 x 10^6 and the LD90 was 5.3 X 10^6 spores/ml 48 h after exposure. The probite line equation was then Y= 1.69 x + 1.79 and R²= 0.9757. Microscope magnifying revealed also the fungal attack via cuticle and mycelia germination one dead larvae and pupae. In semi-field environment, treatment revealed that, at 5.3 x 10^6 spores/ml, the formulation has a great emergence inhibition of mosquito adult formation. No significant difference was observed between dry and rain season application of M. anisopliae on the larvae. Therefore, a combination of M. anisopliae with Suneem may provide a more sustainable management strategy for malaria vectors control at the larval stages. [less ▲]

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See detailStudy of the virulence of african horse sickness virus serotypeS 4 and 9 in two mouse models
De la Grandière de Noronha Cotta, Maria Ana ULg; Francis, Frédéric ULg; Caij, Ann Brigitte et al

Poster (2012, September)

Objectives African horse sickness is an infectious disease caused by a double stranded positive RNA virus which belongs to the family Reoviridae, genus Orbivirus. The virus has nine known antigenically ... [more ▼]

Objectives African horse sickness is an infectious disease caused by a double stranded positive RNA virus which belongs to the family Reoviridae, genus Orbivirus. The virus has nine known antigenically distinct serotypes and is transmitted by a culicoides biting midge, principally Culicoides imicola. African horse sickness causes severe morbidity and mortality up to 95 % in horses with severe economic losses. The establishment of an experimental mouse model is needed for the investigation of the pathogenesis of this infection. Methods Two mouse models, interferon-α receptor knock-out mice and immunocompetent mice, were tested. The used virus for mice inoculations belonged to the two serotypes which caused epidemics in Europe, serotypes 4 and 9. The virus was inoculated by subcutaneous route and/or by intra-nasal route. Samples of whole blood were taken for each infected and knock-out mice at regular intervals. The organs (liver, spleen, kidney, lung and brain) were taken at the end of experience of when the most affected mices were euthanasied. All these samples were tested by a qRT-PCR targeting African horse sickness genome segment 7. Results The results demonstrate the potential of the immunodeficient mouse model for both clinical and biological features. Both serotypes of African horse sickness were detected by qRT-PCR until three weeks post-infection (corresponding with the end of the experience) in blood. Conclusions The setting up of this mouse model has developed a tool for efficient in vivo study to characterize the in vivo virulence of this virus, to monitor the evolution of viral populations during in vivo replication cycles and to test the competence or vectorial capacity of indigenous Culicoides. Acknowledgement Research supported by the Belgium Federal Public Service, Health, Food Chain Safety and Environment. [less ▲]

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See detailLivestock farms in Belgium shelter they the mosquitoes (Diptera, Culicidae) potentially vectors of arboviruses?
Boukraa, Slimane ULg; Zimmer, Jean-Yves ULg; Simonon, Grégory et al

Poster (2012, August 23)

Although no major arbovirus which mosquitoes are responsible for its transmission has been recorded in Belgium in recent decades, environment and climate change, current and future, could favor the ... [more ▼]

Although no major arbovirus which mosquitoes are responsible for its transmission has been recorded in Belgium in recent decades, environment and climate change, current and future, could favor the emergence of vector-borne diseases in the country, by inducing changes on Culicidae populations. This study aims to determine the potential importance of agricultural environments, and especially livestock farms, to welcome and favor the proliferation of certain species of mosquito responsible for transmission of arboviruses. A taxonomic inventory was conducted in 2008 (III, VI and X) and 2009 (V and IX) in ten cattle farms, and in 2010 (X) in ten stables located in Belgium. The harvest of mosquitoes is based on larval sampling at the level of 14 biotopes such as water troughs, used tires, abandoned utensils and temporary puddles or not. The morphotaxonomic study of larvae and genitalia has allowed to identify eight species in 18 study stations. These are Anopheles claviger Meigen, 1804 ; A. maculipennis s.l. Meigen, 1818 ; Culiseta annulata Schrank, 1776 ; Cs. morsitans Theobald, 1901 ; Culex modestus Ficalbi, 1889 ; Cx. torrentium Martini, 1925 ; Cx. territans Walker, 1856 and Cx. pipiens s.l. L., 1758. Of the 1843 individuals examined in 2009, Cx. pipiens s.l. represents 79.98% of the total harvest; however, Cx. modestus represents only 0.92%. Used tires form the most favorable habitat for larval development of Culicidae. 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 ▲]

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See detailPathogenicity test of the fungus Aspergillus clavatus on aphid Acyrthosiphon pisum (Aphididae)
Seye, Fawrou; Bawin, Thomas ULg; Delvigne, Frank ULg et al

Poster (2012, August 19)

Pea aphid is a pest of many cultivated and wild plants, but also a vector of several viral diseases. To control this pest, the most widely used methods are physical, chemical and more recently an ... [more ▼]

Pea aphid is a pest of many cultivated and wild plants, but also a vector of several viral diseases. To control this pest, the most widely used methods are physical, chemical and more recently an integrated approach that includes biological control. With the use of pathogenic agents against insects, the use of entomopathogenic fungi is one of the most promising. The present study demonstrated the possibility of using an entomopathogenic fungus Aspergillus clavatus against aphids. In laboratory conditions (8/16 photoperiod, average temperature 25°C), the insects were in contact with different concentrations ranging from 10^2 to 10^4 spores/cm2 deposited on filter paper in Petri dishes, or applied directly to young plants with doses ranging from 10^4 to 10^6 spores/ml. In 24 hours, mortality was 0 to 31.5% in Petri dishes. For treatment plants, the cumulative mortality in 5 days was 55 to 79%. Microscopic observations showed that the aphids were infected by contact and fungus has a mycosis effect. From these preliminary results, investigations should be made to study the action of the fungus on the reproduction of aphids. Therefore, A. clavatus could be introduced along with other fungi found in the literature as a biological control agent against aphids. [less ▲]

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See detailVolatile organic compounds released by barley roots attract wireworms
Barsics, Fanny ULg; Fiers, Marie ULg; Francis, Frédéric ULg et al

Poster (2012, August)

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

Wireworms, the soil dwelling larvae of click beetles, are pests of many crops worldwide. Alternatives to insecticide treatments are needed for integrated management strategies. Our work consists in elucidating the role of barley (Hordeum vulgare L.) root-emitted volatile organic compounds (VOC) on the orientation behaviour of Agriotes sordidus Illiger wireworms (Fig. 1). Using dual choice olfactometers, we have evaluated the attractiveness of baits ranging from barley roots themselves to one isolated root-emitted volatile organic compound. [less ▲]

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See detailRisk of introduction of alphaviruses responsible for American equine encephalitides in Belgium
De la Grandière de Noronha Cotta, Maria Ana ULg; Dal Pozzo, Fabiana ULg; Francis, Frédéric ULg et al

Poster (2012, August)

Arthropod-borne viruses are a threat for human and animal healths in regards with their dissemination out of their endemic area. The arboviruses reviewed here belong to the family Togaviridae genus ... [more ▼]

Arthropod-borne viruses are a threat for human and animal healths in regards with their dissemination out of their endemic area. The arboviruses reviewed here belong to the family Togaviridae genus Alphavirus and are small enveloped positive sense RNA viruses. They are considered as exotic equid pathogens in Europe and can cause severe diseases in humans in the context of an epidemic. Arboviruses have complex epidemiologic features characterised by interactions between viruses, vectors, reservoir or susceptible host species, and environment. A bibliographic search was performed to identify the mean factors that influenced past outbreaks in America and the presence of potential vectors/vertebrate hosts that could play a role in the transmission cycle in Belgium. Three equine arboviruses, currently considered as the main current threats of emergence/introduction in Western Europe, were chosen as model for this study: Eastern equine encephalitis virus (EEEV), Western equine encephalitis virus (WEEV) and Venezuelan equine encephalitis virus (VEEV). In conclusion, taking into consideration the globalisation (increase of international exchanges) and climate warming, the analysis of the different features of the arbovirus cycles are essential to a balanced risk expertise in the Belgian context. Research supported by the Belgium Federal Public Service, Health, Food Chain Safety and Environment. [less ▲]

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See detailTermites artificially-fed on unusual diet and resulting enzymatic switches
Bauwens, Julien ULg; Tarayre, Cédric ULg; Matteotti, Christel et al

Poster (2012, August)

Wood-feeding termites as Reticulitermes santonensis generally feed on cellulose, hemicelluloses and lignin. However, these opportunistic insects are also able to degrade other carbohydrates, such as ... [more ▼]

Wood-feeding termites as Reticulitermes santonensis generally feed on cellulose, hemicelluloses and lignin. However, these opportunistic insects are also able to degrade other carbohydrates, such as starch. The production of putative endogenous α - amylase has been previously shown in R. flavipes, as the disappearance of the major symbiotic flagellates from the hindgut. Here, we compared enzymatic activities (CMCase, MCCase, xylanase, amylase, α- and β-glucosidase) between different fractions of the digestive tract of starch-, cellulose-, and wood-fed termites. Main compounds of the artificial diets, namely starch or MCC, resulted in differential enzymatic activity. Even the substitution of wood by artificial diets itself seemed to induce changes in enzymatic activities, regardless of the main substrate in the diet, as we observed strong midgut α-glucosidase activity only for artificially-fed termites. Preliminary assays to isolate and characterize enzymes were performed using proteomic methods. [less ▲]

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See detailBreeding sites of main Bluetongue virus vectors in Belgian cowshed
Zimmer, Jean-Yves ULg; Saegerman, Claude ULg; Losson, Bertrand ULg et al

Poster (2012, August)

Bluetongue (BT) is an emerging vectorborne disease of ruminants that was reported in August 2006 in northern Europe. Since 2007, BT virus (BTV) serotype 8 continued its spread across Europe and caused ... [more ▼]

Bluetongue (BT) is an emerging vectorborne disease of ruminants that was reported in August 2006 in northern Europe. Since 2007, BT virus (BTV) serotype 8 continued its spread across Europe and caused considerable economic losses. This observation indicates possible overwintering of the vector from year to year. The biological vectors of BTV are biting midges of the genus Culicoides. Breeding sites of bluetongue vector species have been found near farms (e.g. silage residues) and in neighboring meadows (e.g. cattle dung) but never inside sheds. We conducted a study in five cattle farms in Belgium during February–October 2008. Three samplings were performed and each soil sample collected inside cowsheds was incubated to enable adult midges to emerge. Among 15 soil biotopes sampled, only one showed the emergence of adult Culicoides biting midges: dried dung adhering to walls inside animal enclosures and resulting to the partial removal of used animal litter. It was a breeding site for the C. obsoletus/C. scoticus complex. Physico-chemical characteristics showed that midges of this complex are more prevalent in soil samples with a high carbon:nitrogen (C:N) index. So Culicoides biting midges are able to complete their life cycle in animal enclosures. We identified a breeding site for the primary BTV vector in a cowshed in northern Europe. These observations could explain the persistence of BTV from year to year despite fairly harsh winters. Hygienic measures on farms could reduce biting midges populations and so improve efficacy of vaccination campaigns against BT in Europe. [less ▲]

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See detailProteomics of aphid salivary proteins
Francis, Frédéric ULg; De Pauw, Edwin ULg; Vandermoten, Sophie ULg et al

Conference (2012, August)

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See detailEffect of reduced water supply on aphid physiology : A proteomic approach on peach-aphid interaction
Verdugo, Jaime; Lacroze, Jean-philippe; Sauge, Marie-Hélène et al

Poster (2012, August)

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See detailFeeding humans with edible insects : actual state and perspectives in Belgium and Europe
Sablon, Ludovic ULg; Alabi, Taofic; Drugmand, Didier et al

Poster (2012, August)

In future decades, world population will grow up to 9 billion of people and we will be confronted to a lack of nutritive resources. We will not continue to produce proteins with our conventional livestock ... [more ▼]

In future decades, world population will grow up to 9 billion of people and we will be confronted to a lack of nutritive resources. We will not continue to produce proteins with our conventional livestock as beef, poultry or pig. It will therefore look to other sources and edible insects are one of these solutions. Indeed, more than 2000 species of edible insects were actually consumed by 3000 ethnic groups in the world. In undernourished populations, entomophagy is essential to relieve deficiencies in proteins, fatty acids and some vitamins. In Europe, we have acquired sedentary habits and we have lost our ancestral harvesting and hunting traditions. It is the reason of disinterest for edible insects and entomophagy was considered as a "barbarian" food habit. Facing food challenges of tomorrow, it is important to sensitize industrialized populations and to reintroduce edible insects in our plates and habits. The first step is to overcome neophobia of food products. Our studies focused on different insect preparations and on perception of entomophagy by different age classes. Globally, our first results indicated that entomophagy was accepted by belgian consumers but the more difficult for them is to taste the first time. These results confirmed neophobia for this type of food products and thus the importance of positive informations and education for acceptance of entomophagy. [less ▲]

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

Poster (2012, August)

Originally introduced as a biological control agent, the multicoloured Asian ladybeetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become an invasive pest throughout Europe and North ... [more ▼]

Originally introduced as a biological control agent, the multicoloured Asian ladybeetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), has become an invasive pest throughout Europe and North America in the last few years. Although its effectiveness to control aphid and coccid populations was impressive, some negative impacts appeared rapidly, notably on human health. Indeed, to protect themselves from cold temperatures, H. axyridis individuals move inside dwellings and buildings and form large aggregations in concealed portions of structures to overwinter. The aggregating beetles are responsible for some annoyances due to, on one hand, the number of individuals inside homes and, on the other hand, the hemolymph secretions they release when they are disturbed, which can cause allergic reactions. 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. This survey was mainly focused on a general description of the infested house (type, colour, infested floor(s), building material), the orientation of the colonized rooms and the position of the beetles’ cluster. The collected data 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, west or southwest oriented rooms. Furthermore, ladybeetles generally gathered into wooden windows frames facing south, west or southwest and to a lesser extent, in the upper corners of walls presenting the same orientation. All these results contribute to improve the knowledge on the aggregative behaviour of H. axyridis and could promote the development of more specific and efficient management methods to prevent massive infestations into dwellings, such as artificial shelters or trapping systems located at the outside of buildings. [less ▲]

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