References of "Francis, Frédéric"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailProduction of two entomopathogenic Aspergillus species and insecticidal activity against the mosquito Culex quinquefasciatus compared to Metarhizium anisopliae
Bawin, Thomas ULg; Seye, Fawrou; Boukraa, Slimane ULg et al

in Biocontrol Science & Technology (2016), 26(5), 617-629

Entomopathogenic micro-organisms including fungi have become increasingly studied for integrated pest management. The spore productivity and insecticidal activity of two opportunistic insect pathogenic ... [more ▼]

Entomopathogenic micro-organisms including fungi have become increasingly studied for integrated pest management. The spore productivity and insecticidal activity of two opportunistic insect pathogenic Aspergillus species (namely: Aspergillus clavatus Desmazieres and Aspergillus flavus Link (Ascomycota: Eurotiales, Trichocomaceae)) were compared to Metarhizium anisopliae sensu lato (Metchnikoff) Sorokin (Ascomycota: Hypocreales, Clavicipitaceae) for mosquito (Diptera: Culicidae) control. The production of aerial spores on wheat bran and white rice was investigated in solid-, semi-solid-, and liquid-state media supplemented with a nutritive solution. Wheat bran-based media were suitable for spore production and increased the spore yield in solid-state from 3 to 7 fold: A. clavatus produced 48.4 ± 5.2 and 15.7 ± 1.6 x 10^8 spores/g, A. flavus produced 22.3 ± 4.1 and 3.1 ± 2.5 x 10^8 spores/g, and M. anisopliae produced 39.6 ± 6.5 and 13.1 ± 2.6 x 10^8 spores/g of wheat bran or white rice, respectively. A. clavatus, A. flavus and M. anisopliae spores harvested from wheat bran-based solid-state media showed lethal concentrations (LC50) of 1.1, 1.8, and 1.3 x 10^8 spores/ml against Culex quinquefasciatus Say larvae in 72 h. Because A. clavatus and M. anisopliae displayed similar features when cultured under these conditions, our results suggest that insect pathogenic Aspergillus species may be as productive and virulent against mosquito larvae as a well-recognized entomopathogenic fungus. Wheat bran could advantageously be used in large-scale fermentation for a possible cost-effective pest control using these fungi. [less ▲]

Detailed reference viewed: 46 (11 ULg)
Full Text
Peer Reviewed
See detailSURVEYS OF APHIDS AND POTATO VIRUS Y IN POTATO FIELDS IN WALLONIA, BELGIUM: A FOUR YEAR OVERVIEW
Bosquée, Emilie ULg; Yattara, Almouner A.; Crutzen, François et al

in Journal of Plant Pathology [=JPP] (2016)

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified ... [more ▼]

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified using yellow pan traps. Four thousands potato leaf samples collected in 87 plots from 29 fields were analysed for the presence and typing of PVY strains by RT-PCR. PVY was detected in 26%, 20% and 60% of the seed plots tested from 2009 to 2011, respectively. A higher prevalence of PVY was observed in plots of stock potatoes (60% in 2010 and 67% in 2011). The N/NTN strain of PVY was predominant, representing 70-99% of the strains. [less ▲]

Detailed reference viewed: 38 (7 ULg)
Full Text
Peer Reviewed
See detailForaging wireworms are attracted to root-produced volatile aldehydes
Barsics, Fanny ULg; Delory, Benjamin M.; Delaplace, Pierre ULg et al

in Journal of Pest Science (2016)

Soil-dwelling insects are known to react to chemical cues they encounter in the rhizosphere. Whether wireworms (Coleoptera, Elateridae) use root-emitted volatile organic chemicals to localize their host ... [more ▼]

Soil-dwelling insects are known to react to chemical cues they encounter in the rhizosphere. Whether wireworms (Coleoptera, Elateridae) use root-emitted volatile organic chemicals to localize their host plant remains, however, poorly understood. Here, we aimed at identifying chemical cues released by barley roots that attract Agriotes sordidus. In a first behavioral experiment, we assessed the ability of wireworms to orient towards live barley roots, using dual-choice olfactometers suitable for belowground insects. Then, we collected the volatile organic compounds (VOC) produced by barley roots using a dynamic head-space sampling approach. VOC were quantified and identified using gas chromatography—mass spectrometry (GC–MS). The odorant blend is composed of four aldehydes, namely hexanal, (E)-hex-2-enal, (E)-non-2-enal, and (E,Z)-nona-2,6-dienal. In a second set of dual-choice bioassays, wireworms were attracted towards a synthetic blend of these four major compounds. However, the synthetic blend was not as attractive as live roots, which is partially explained by the absence of CO2, commonly known as a strong attractant for soil-dwelling insects. While CO2 indicates the presence of living material in the vicinity, we hypothesize that additional VOC inform about the plant suitability. A better understanding of these belowground signals would contribute to the development of new integrated control strategies against wireworms. [less ▲]

Detailed reference viewed: 45 (4 ULg)
Full Text
Peer Reviewed
See detailDiversity and ecology survey of mosquitoes potential vectors in Belgian equestrian farms: A threat prevention of mosquito-borne equine arboviruses
Boukraa, Slimane ULg; de la Grandière, Maria Ana ULg; Bawin, Thomas ULg et al

in Preventive Veterinary Medicine (2016), 124

Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne ... [more ▼]

Emergence of West Nile Virus was recently recorded in several European countries, which can lead to severe health problems in horse populations. Europe is also at risk of introduction of mosquito-borne equine alphavirus from Americas. Prevention of these arboviruses requires a clear understanding of transmission cycles, especially their vectors. To characterize mosquito fauna, their ecology and identify potential vectors of equine arboviruses in Belgium, entomological surveys of six equestrian farms located in the Wolloon Region were conducted during 2011–2012. The harvest of mosquitoes was based on larval sampling (272 samples from 111 breeding sites) and monthly adults trapping (CO2-baited traps, Mosquito Magnet Liberty Plus). Among 51,493 larvae and 319 adult mosquitoes collected, morphological identification showed the presence of 11 species: Anopheles claviger (Meigen), An. maculipennis s.l. (Meigen), An. plumbeus (Stephens), Culex hortensis (Ficalbi), Cx. territans (Walker), Cx. pipiens s.l. L., Cx. torrentium (Martini), Coquillettidia richiardii (Ficalbi), Culiseta annulata (Schrank), Aedes cantans (Meigen), Ae. geniculatus (Olivier). Molecular identification of Cx. pipiens species complex allowed the detection of three molecular forms, Pipiens (92.3%), Molestus (4.6%) and Hybrid (3.1%). Larvae of Cx. pipiens sl and Cx. torrentium were omnipresent and the most abundant species. Water troughs, ponds and slurry (liquid manure) were the most favorable breeding sites of mosquito larvae. Based upon behavior and ecology of the identified mosquito species, Studied Belgian equestrian farms seem to provide a suitable environment and breeding sites for the proliferation of potential vectors of arboviruses and those being a real nuisance problem for horses and neighboring inhabitants. [less ▲]

Detailed reference viewed: 36 (7 ULg)
Full Text
Peer Reviewed
See detailSynthèse bibliographique sur le comportement de recherche de l’hôte chez la punaise de lit (Cimex lectularius) et applications dans le cadre de la lutte intégrée
Legrand, Pauline ULg; Verheggen, François ULg; Haubruge, Eric ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), 20(2),

This study analyzes host-seeking behavior in the common bed bug, Cimex lectularius, paying particular attention to human stimuli involved in this orientation process. The potential applications in ... [more ▼]

This study analyzes host-seeking behavior in the common bed bug, Cimex lectularius, paying particular attention to human stimuli involved in this orientation process. The potential applications in integrated pest management are discussed. The common bed bug is an obligate hematophagous that has been associated with humans for millennia. When searching for food, this insect relies for orientation on signals produced by its hosts. Carbon dioxide emitted by human respiration is more attractive to bugs than body heat. The response of bed bugs to other volatile organic compounds released by the human body has been tested, but their perception and behavioral impact are not always studied together, and some discrepancies occasionally appear. Currently, carbon dioxide is the most efficient lure for bed bugs, although real human bait is more attractive. Some home-made traps baited with dry ice are more efficient than other traps using complicated chemical blends. Dry ice seems to be more efficient as a lure than complex chemical blends, and it can be used in simple traps. Our knowledge of host-seeking behavior in bed bugs is still partial and new questions are constantly arising. Further efforts in the study of the chemical ecology of this process are needed in order to improve the management of this pest. The control of bed bugs in European countries appears to be a major challenge for the years to come. [less ▲]

Detailed reference viewed: 16 (3 ULg)
Full Text
Peer Reviewed
See detailContribution à l’écologie des coléoptères coprophiles et coprophages en Belgique : diversité spécifique, préférences stercorales et phénologie
Bebermans, Julien ULg; Fagot, Jean ULg; Francis, Frédéric ULg

in Entomologie Faunistique = Faunistic Entomology (2016), 69

In a study performed from September to October 2014, coprophagous and coprophilic beetle of cattle and horse dung were observed. This research focused on Scarabaeoidea super-family and Staphylinidae ... [more ▼]

In a study performed from September to October 2014, coprophagous and coprophilic beetle of cattle and horse dung were observed. This research focused on Scarabaeoidea super-family and Staphylinidae family. Totally, 6245 individuals, belonging to 15 coprophagous scarabs species and 73 staphylinids species were identified. Insects have been captured using a trap weekly visited. Three geographic regions were compared: Pays de Herve, Hesbaye and Pays Brabançon with one trapping site by region, respectively Julémont, Waremme and Grez-Doiceau. One of the objectives was to observe the insects population diversity according to dung type and identify insect preference related to a specific type of dung. The goal was to observe if the communities change between regions. The population dynamics during the ageing of dung has also been considered. Several species showed a significant preference for one of the two kind of feces, even if there are no strict specialist insects. Also, Julémont appeared as being the most diversified site regarding staphylinds, while Grez-Doiceau seemed to be the most suitable place concerning scarabs. Finally, insects were found to invade very quickly the freshly dropped dung, while they seem less attracted after a few days. [less ▲]

Detailed reference viewed: 15 (2 ULg)
Full Text
Peer Reviewed
See detailEarthworms Eisenia fetida affect the uptake of heavy metals by plants Vicia faba and Zea mays in metal-contaminated soils
Lemtiri, Aboulkacem ULg; Liénard, Amandine ULg; Alabi, Taofic ULg et al

in Applied Soil Ecology (2016), 104

Earthworms increase the availability of heavy metals in some situations and aid in maintaining the structure and quality of soil. The introduction of earthworms into metal-contaminated soils has been ... [more ▼]

Earthworms increase the availability of heavy metals in some situations and aid in maintaining the structure and quality of soil. The introduction of earthworms into metal-contaminated soils has been suggested as an aid for phytoremediation processes. In Wallonia, Belgium, a century of industrial metallurgic activities has led to the substantial pollution of soils by heavy metals, including copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd), due to atmospheric dusts. Two plant species, Vicia faba and Zea mays, and earthworms (Eisenia fetida) (Savigny, 1826) were exposed to different concentrations of long-term-contaminated soils for 42 days. The soil samples, which were collected from the land surrounding a former Zn-Pb ore-treatment plant, exhibited different levels of heavy metals. Our aim was to evaluate the role of earthworms E. fetida on the availability of metals in soils and their effects on metal uptake by V. faba and Z. mays plants at different soil concentrations. The results suggest that earthworms and plants modified the availability of metals in contaminated soils after 42 days of exposure. Earthworm life-cycle parameters were affected by metal contamination and/or the addition of plants; cocoon production and weight were more responsive to adverse conditions than earthworm survival or weight change. The concentrations of Pb and Cd in earthworm tissues decreased in the presence of plants. Results showed that metal accumulation in plants depended on the metal element considered and the presence of earthworms. However, the presence of earthworms did not change the concentrations of metals in plants, except for Cd. In the presence or absence of earthworms, V. faba accumulated higher concentrations of Cu and Zn compared with Z. mays, which accumulated higher concentrations of Cd. These findings have revealed that earthworm activities can modify the availability of heavy metals for uptake by plants in contaminated soils. Moreover, the study results show that the ecological context of phytoremediation should be broadened by considering earthworm-plant-soil interaction, which influence both the health of the plant and the uptake of heavy metals by plants. [less ▲]

Detailed reference viewed: 39 (10 ULg)
Full Text
Peer Reviewed
See detailTowards sustainable food systems: the concept of agroecology and how it questions current research practices. A review
Hatt, Séverin ULg; Artru, Sidonie ULg; Brédart, David ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), 20(Special issue 1), 215-224

Introduction. Multiple environmental and socio-economic indicators show that our current agriculture and the organization of the food system need to be revised. Agroecology has been proposed as a ... [more ▼]

Introduction. Multiple environmental and socio-economic indicators show that our current agriculture and the organization of the food system need to be revised. Agroecology has been proposed as a promising concept for achieving greater sustainability. This paper offers an overview and discussion of the concept based on existing literature and case studies, and explores the way it questions our current research approaches and education paradigms. Literature. In order to improve the sustainability of agriculture, the use of external and chemical inputs needs to be minimized. Agroecological farming practices seek to optimize ecological processes, thus minimizing the need for external inputs by providing an array of ecosystem services. Implementing such practices challenges the current structure of the food system, which has been criticized for its lack of social relevance and economic viability. An agroecological approach includes all stakeholders, from field to fork, in the discussion, design and development of future food systems. This inclusion of various disciplines and stakeholders raises issues about scientists and their research practices, as well as about the education of the next generation of scientists. Conclusions. Agroecology is based on the concept that agricultural practices and food systems cannot be dissociated because they belong to the same natural and socio-economic context. Clearly, agroecology is not a silver-bullet, but its principles can serve as avenues for rethinking the current approaches towards achieving greater sustainability. Adapting research approaches in line with indicators that promote inter- and transdisciplinary research is essential if progress is to be made. [less ▲]

Detailed reference viewed: 97 (22 ULg)
Full Text
Peer Reviewed
See detailConsumer acceptance of insect-based alternative meat products in Western countries
Caparros Megido, Rudy ULg; Gierts, Chloé; Blecker, Christophe ULg et al

in Food Quality & Preference (2016)

During the past few years, entomophagy has been increasing in significance. As insects are generally high in protein, they are principally considered as meat substitutes. Nevertheless, in Western ... [more ▼]

During the past few years, entomophagy has been increasing in significance. As insects are generally high in protein, they are principally considered as meat substitutes. Nevertheless, in Western countries, meat substitute consumption is actually very low, principally due to food neophobia and poor sensory qualities in comparison with meat. In insect particular case, food neophobia is clearly high. To reduce insect food neophobia, previous studies suggest to insert invisible insect in food preparation and/or to associate them with known flavors. In this study, a survey on entomophagy perception and hedonic tests were realized to assess the level of sensory-liking of hybrid insect-based burgers (beef, lentils, mealworms and beef, mealworms and lentils). Participants’ overall liking of the four burgers differed between genders and was influenced by burger appearance and taste. Women clearly preferred beef burger appearance, whereas men preferred the appearance of beef and insect-based burgers. Concerning insect-based burger taste, participants (men and women) rated it intermediately, between that of the beef and lentil burger, with a preference for the mealworm and beef burger. Results also showed that people with previous entomophagy experience was limited but that they gave globally higher ratings to all preparations. In conclusion, insect tasting sessions are important to decrease food neophobia, as they encourage people to “take the first step” and become acquainted with entomophagy. Nevertheless, insect integration into Western food culture will involve a transitional phase with minced or powdered insects incorporated into ready-to-eat preparations, as people are not ready to add insects to their diets in “whole form.” [less ▲]

Detailed reference viewed: 37 (9 ULg)
Full Text
Peer Reviewed
See detailOptimization of a cheap and residential small-scale production of edible crickets with local by-products as an alternative protein-rich human food source in Ratanakiri Province (Cambodia)
Caparros Megido, Rudy ULg; Alabi, Taofic ULg; Nieus, Clément et al

in Journal of the Science of Food and Agriculture (2016)

Background - Health status of the indigenous people of the Ratanakiri Province, Cambodia, is significantly lower compared to the rest of the nation. The domestication and mass production of insects may ... [more ▼]

Background - Health status of the indigenous people of the Ratanakiri Province, Cambodia, is significantly lower compared to the rest of the nation. The domestication and mass production of insects may represent a sustainable, cost effective and high quality alternative source of protein to traditional livestock. This study aimed to optimise a cheap and residential cricket breeding system based on unused wild resources. The cricket development, Teleogryllus testaceus (Walker), under seven diets composed of taro aerial parts, young cassava leaves, young cashew leaves and brown rice flour (with or without banana slices), versus a traditionally used broiler feed diet was studied. Results - Cricket mortality was low in all diets, except the two cashew-based diets. Total biomass was significantly higher under the broiler feed, in addition to the two diets containing a combination of cassava leaf powder and brown rice. Yet, crickets fed with the taro diet had the highest percentage of protein. Concerning the breeding system cost, units using cassava leaves were the cheapest ones. Conclusion – Diets based of cassava leaves seems to be the most promising ones. Nevertheless, to produce crickets with a high body mass and a high protein level, a new experiment must be realised in which the cassava leaf maturity will be adapted to fit with the cricket growth stage. Moreover, to reduce the cost of the breeding units, handmade local products should be used instead of purchased components. [less ▲]

Detailed reference viewed: 84 (31 ULg)
Full Text
Peer Reviewed
See detailPreliminary report of mosquitoes survey at Tonga Lake (North-East Algeria)
Amara Korba, Raouf; Boukraa, Slimane ULg; Alayat, Moufdia Saoucen et al

in Advances in Environmental Biology (2016), 9(27), 288-294

Background: Mosquitoes are transmitters of several human diseases including, malaria, filariasis, West Nile virus and Rift Valley fever virus. To planified and succeful any mosquito vector control, a good ... [more ▼]

Background: Mosquitoes are transmitters of several human diseases including, malaria, filariasis, West Nile virus and Rift Valley fever virus. To planified and succeful any mosquito vector control, a good understanding of the occurrence of specific important vector species, their abundance and distribution are needed. Objectives: The present study aimed to identify the mosquito potential vectors distributed throughout Tonga Lake region, a part of National Park of El-Kala situated in northeastern Algeria and to discuss the epidemiological importance of these insects. Results: Thirteen species representing five genera were identified: Ae. brelandi, Ae. vexans, An. plumbeus, An. labranchiae, Cx. pipiens s. l., Cx. perexiguus, Cx. theileri, Cx. pusillus, Cx. modestus, Cx. impudicus, Cs. longiareolata, Cs. annulata, Ur. unguiculata. The dominant species was Cx. pipiens s. l. with more than 70%. Conclusion: The occurrence of Aedes, Anopheles and Culex is suggestive of the presence of a risk for vector-borne diseases such as malaria, West Nile fever, Rift Valley Fever and filariasis in the area. In this study, results on species diversity may help in the future planning of vector control measures. [less ▲]

Detailed reference viewed: 36 (1 ULg)
Full Text
Peer Reviewed
See detailMolecular detection of six (endo-) symbiotic bacteria in Belgian mosquitoes: first step towards the selection of appropriate paratransgenesis candidates
Raharimalala, Fara Nantenaina; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

in Parasitology Research (2016)

Actually, the use of symbiotic bacteria is one of alternative solution to avoid vector resistance to pesticides. In Belgium, among 31 identified mosquito species, 10 were considered as potential vectors ... [more ▼]

Actually, the use of symbiotic bacteria is one of alternative solution to avoid vector resistance to pesticides. In Belgium, among 31 identified mosquito species, 10 were considered as potential vectors. Given to introduction risks of arbovirosis, the purpose of this study was to investigate the presence of symbiosis bacteria in potential mosquito vectors. Eleven species caught from 12 sites in Belgium were used: Culex pipiens s.l., Culex torrentium, Culex hortensis, Anopheles claviger, Anopheles maculipennis s.l., Anopheles plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Ochlerotatus dorsalis, Aedes albopictus, and Coquillettidia richiardii. Six genera of symbiotic bacteria were screened: Wolbachia sp., Comamonas sp, Delftia sp., Pseudomonas sp., Acinetobacter sp., and Asaia sp.Atotal of 173 mosquito individuals (144 larvae and 29 adults) were used for the polymerase chain reaction screening. Wolbachia was not found in any Anopheles species nor Cx. torrentium. A total absence of Comamonas and Delftia was observed in all species. Acinetobacter, Pseudomonas, and Asaia were found in most of species with a high prevalence for Pseudomonas. These results were discussed to develop potential strategy and exploit the variable occurrence of symbiotic bacteria to focus on them to propose biological ways of mosquito control. [less ▲]

Detailed reference viewed: 39 (9 ULg)
Full Text
Peer Reviewed
See detailImpact of climatic factors on the release of E-β-caryophyllene from alginate beads
Daems, Frédéric ULg; Bera, François ULg; Lorge, Stéphanie ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2016), 20(2),

Description of the subject. Alginate beads that release semiochemical compounds are interesting biological control devices used to attract the natural enemies of aphids in infested crops. Little ... [more ▼]

Description of the subject. Alginate beads that release semiochemical compounds are interesting biological control devices used to attract the natural enemies of aphids in infested crops. Little information, however, is available about the impact of climatic factors on the release of semiochemicals from this diffusive system. Objectives. The objective of this scoping study was to investigate the impact of temperature, relative humidity and wind speed, on the release of E-β-caryophyllene from alginate beads. Method. The impact of the three climatic factors on the release of E-β-caryophyllene from alginate beads was evaluated using a Box-Behnken experimental design and a laboratory scale volatile collection system. The influence of relative humidity on bead water content and size, with and without this semiochemical, was also investigated using a gravimetric method and an easy-to-use photographic device, respectively. Results. The results showed that an increase in temperature caused a significant increase in the E-β¬-caryophyllene release rate. Neither relative humidity nor airflow, however, had a significant effect on the release of this semiochemical when relative humidity and wind speed ranged from 33% to 75% and from 6.61 x10-4 m.s-1 to 2.05 x10-2 m.s-1, respectively. The isotherm curves obtained were characteristic of food products and biopolymer materials. The isotherm shapes were not modified by the incorporation of the semiochemical into alginate beads, and showed an important increase in water content when relative humidity values exceeded 85%. Fortunately, this water content increase did not affect bead size, which facilitates the calculation of E-β-caryophyllene release. Conclusion. The present study shows for the first time the impact of the three main climatic factors on the release of E-β-caryophyllene from alginate beads. It allows learning more about how these biological control devices operate in order to optimize future field trials. [less ▲]

Detailed reference viewed: 45 (7 ULg)
Full Text
See detailClé d'identification des principales familles d'insectes d'Europe
Mignon, Jacques ULg; Haubruge, Eric ULg; Francis, Frédéric ULg

Book published by Presses agronomiques de Gembloux (2016)

Quelques insectes particuliers sont identifiables du premier coup d’œil ou par comparaison avec des illustrations de qualité. Malheureusement, il s’agit là d’exceptions et l’étude des insectes est souvent ... [more ▼]

Quelques insectes particuliers sont identifiables du premier coup d’œil ou par comparaison avec des illustrations de qualité. Malheureusement, il s’agit là d’exceptions et l’étude des insectes est souvent rendue complexe par la nécessité d’utiliser une loupe binoculaire et de maîtriser un vocabulaire spécifique difficilement accessible aux néophytes. Principalement destinée à l’enseignement de l’entomologie, la présente clé d’identification permet de donner un nom à quelque 180 familles ou super-familles d’insectes parmi les plus couramment rencontrées en Europe. Le vocabulaire utilisé est accessible à toute personne ayant des notions de base de la morphologie des insectes. Un glossaire et des figures permettent de combler certaines lacunes et de donner sens aux critères d’identification rencontrés. Reconnaître un insecte au niveau de la famille permet d’obtenir rapidement des précisions sur sa biologie et constitue une étape indispensable vers une connaissance approfondie des différentes espèces. [less ▲]

Detailed reference viewed: 91 (8 ULg)
Full Text
Peer Reviewed
See detailA metagenomic approach from aphid’s hemolymph sheds light on the potential roles of co-existing endosymbionts
De Clerck, Caroline ULg; Fujiwara, Akiko; Joncour, Pauline et al

in Microbiome (2015), 3(63),

Background: Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory ... [more ▼]

Background: Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory symbiont present in aphids, supplying essential nutrients that are missing in the plants phloem to its host. Pentalonia nigronervosa is the main vector of the banana bunchy top virus, one of the most damageable viruses in banana. This aphid is carrying two symbionts: B. aphidicola (BPn) and Wolbachia sp. (wPn). The high occurrence of Wolbachia in the banana aphid raises questions about the role it plays in this insect. The goal of this study was to go further in the understanding of the role played by the two symbionts in P. nigronervosa. To do so, microinjection tests were made to see the effect of wPn elimination on the host, and then, high-throughput sequencing of the haemolymph was used to analyze the gene content of the symbionts. Results: We observed that the elimination of wPn systematically led to the death of aphids, suggesting that the bacterium could play a mutualistic role. In addition, we identify and annotate 587 and 250 genes for wPn and BPn, respectively, through high-throughput sequencing. Analysis of these genes suggests that the two bacteria are working together for the production of several essential nutrients. The most striking cases are for lysin and riboflavin which are usually provided by B. aphidicola alone to the host. In the banana aphid, the genes involved in the production pathways of these metabolites are shared between the two bacteria making them both essential for the survival of the aphid host. Conclusions: Our results suggest that a co-obligatory symbiosis between B. aphidicola and Wolbachia occurs in the banana aphid, the two bacteria acting together to supply essential nutrients to the host. This is, to our knowledge, the first time Wolbachia is reported to play an essential role in aphids. [less ▲]

Detailed reference viewed: 31 (3 ULg)
Full Text
Peer Reviewed
See detailUpdated checklist of the mosquitoes (Diptera: Culicidae) of Belgium
Boukraa, Slimane ULg; Dekoninck, Wouter; Versteirt, Veerle et al

in Journal of Vector Ecology : Journal of the Society for Vector Ecology (2015), 40(2), 398-407

Most information about the systematics and bioecology of Belgian mosquitoes dates back from before 1950, and only scattered information was produced during the last decades. In this paper we review and ... [more ▼]

Most information about the systematics and bioecology of Belgian mosquitoes dates back from before 1950, and only scattered information was produced during the last decades. In this paper we review and update the list of mosquito species recorded in Belgium, from first report (1908) to 2015. Six genera and 31 species were recorded so far, including 28 autochthonous species and three invasive alien species recently recorded in Belgium: Aedes albopictus (Skuse 1894), Ae. japonicus japonicus (Theobald 1901), and Ae. koreicus (Edwards 1917). The six genera are Anopheles (five species), Aedes (sixteen species), Coquillettidia (one species), Culex (four species), Culiseta (four species), and Orthopodomyia (one species). [less ▲]

Detailed reference viewed: 32 (5 ULg)
See detailLes insectes dans l'agriculture
Hatt, Séverin ULg; Francis, Frédéric ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 25 (2 ULg)