References of "Francis, Frédéric"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailAssessing the foraging behavior of Agriotes sordidus wireworms in dual-choice olfactometers
Barsics, Fanny ULg; Fiers, Marie; Fauconnier, Marie-Laure ULg et al

in Communications in Agricultural and Applied Biological Sciences (in press)

The different steps of the foraging process of wireworms (Coleoptera: Elateridae) would be better understood if accurate and holistic information regarding the role of plant-produced chemicals ... [more ▼]

The different steps of the foraging process of wireworms (Coleoptera: Elateridae) would be better understood if accurate and holistic information regarding the role of plant-produced chemicals constituting their environment were available. Volatile organic compounds (VOC) play important roles in the interactions between plants and insects in many ecosystems, whether they take place aboveground or belowground. The roles of VOC are still relatively unknown for wireworms, and deserve attention. Here, we performed three experimentations with barley roots as baits. In the two first, we assessed the effect of chopped roots and fungus infected roots on the orientation of wireworms. In the third experiment, the larvae were confronted to both healthy and fungus infected roots. We discuss the results in terms of suitability of the olfactometers we designed for the investigation of olfaction in wireworms, and we provide suggestions to improve their use. [less ▲]

Detailed reference viewed: 51 (4 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 (2015)

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: 14 (3 ULg)
Full Text
Peer Reviewed
See detailClimate Change and Tritrophic Interactions: Will Modifications to Greenhouse Gas Emissions Increase the Vulnerability of Herbivorous Insects to Natural Enemies?
Boullis, Antoine ULg; Francis, Frédéric ULg; Verheggen, François ULg

in Environmental Entomology (2015)

Insects are highly dependent on odor cues released into the environment to locate conspecifics or food sources. This mechanism is particularly important for insect predators that rely on kairomones ... [more ▼]

Insects are highly dependent on odor cues released into the environment to locate conspecifics or food sources. This mechanism is particularly important for insect predators that rely on kairomones released by their prey to detect them. In the context of climate change and, more specifically, modifications in the gas composition of the atmosphere, chemical communication-mediating interactions between phytophagous insect pests, their host plants, and their natural enemies is likely to be impacted. Several reports have indicated that modifications to plants caused by elevated carbon dioxide and ozone concentrations might indirectly affect insect herbivores, with community-level modifications to this group potentially having an indirect influence on higher trophic levels. The vulnerability of agricultural insect pests toward their natural enemies under elevated greenhouse gases concentrations has been frequently reported, but conflicting results have been obtained. This literature review shows that the higher levels of carbon dioxide, as predicted for the coming century, do not enhance the abundance or efficiency of natural enemies to locate hosts or prey in most published studies. Increased ozone levels lead to modifications in herbivore-induced volatile organic compounds (VOCs) released by damaged plants, which may impact the attractiveness of these herbivores to the third trophic level. Furthermore, other oxidative gases (such as SO2 and NO2) tend to reduce the abundance of natural enemies. The impact of changes in atmospheric gas emissions on plant–insect and insect–insect chemical communication has been under-documented, despite the significance of these mechanisms in tritrophic interactions. We conclude by suggesting some further prospects on this topic of research yet to be investigated. [less ▲]

Detailed reference viewed: 30 (7 ULg)
Full Text
Peer Reviewed
See detailAphid species and associated natural enemies in field crops: what about the invasive ladybird Harmonia axyridis (Coleoptera: Coccinellidae)?
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

in Entomologie Faunistique = Faunistic Entomology (2015), 68

Following the introduction in the 80's of the invasive coccinellid species Harmonia axyridis (Pallas) in Europe, several studies have begun to focus on the interactions with other aphid predator species ... [more ▼]

Following the introduction in the 80's of the invasive coccinellid species Harmonia axyridis (Pallas) in Europe, several studies have begun to focus on the interactions with other aphid predator species. In this study, aphids and associated predators were sampled to determine their relative abundance in four agricultural crops (broad bean, corn, potato, and wheat) in Belgium during 2010 and 2011. The Moericke trap was used to quantify the mean number of aphids and aphid predators from May to September in both years. A total of 28 aphid species and 21 aphidophagous species were observed. In both years, H. axyridis was among the most abundant aphidophagous predators in all four crops, and was the second most abundant coccinellid species after Coccinella septempunctata L. The community of aphidophagous species was similar across all four inventoried crops. However, the highest population densities of this alien species were recorded in broad bean and potato crops, which also hosted the highest aphid population densities. In conclusion, this study demonstrates that the communities of aphid predators are highly diversified in the agroecosystems, despite the high occurrence of H. axyridis, an introduced predator that has become well established in this environment. [less ▲]

Detailed reference viewed: 9 (3 ULg)
Full Text
Peer Reviewed
See detailMyzus persicae feeding on water stressed Arabidopsis affects the emission profile of plant volatile organic compounds
Truong, Dieu-Hien; Delaplace, Pierre ULg; Brostaux, Yves ULg et al

in Journal of Environment and Ecology (2014), 5(2),

Emissions of volatile organic compounds (VOCs) by water-controlled or water-stressed Arabidopsis thaliana infested or not infested with Myzus persicae were evaluated by headspace solid phase ... [more ▼]

Emissions of volatile organic compounds (VOCs) by water-controlled or water-stressed Arabidopsis thaliana infested or not infested with Myzus persicae were evaluated by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The infestations were maintained for 0–24 h, 24–48 h, and 48–72 h, and the emission profile for each time period was determined. Under these controlled conditions, the proportion of 4-methylpentyl isothiocyanate and dimethyl disulfide emitted by aphid-infested, water-stressed Arabidopsis was greater than that for aphid-infested water-controlled Arabidopsis over the 48–72 h sampling period. The proportion of terpene emitted by aphid-infested water-stressed plants also significantly increased compared with the other treatments over the three assayed sampling periods. In contrast, the proportion of 2-ethylhexanal (the only detected aldehyde) and ketones for the water-controlled plants generally remained high following aphid infestation. Taken together, these original data ascertain that abiotic factors can greatly interact to biotic stresses to alter the VOC emission profiles of plants. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailFirst Evidence of a Volatile Sex Pheromone in Lady Beetles
Fassotte, Bérénice ULg; Fischer, Christophe ULg; Durieux, Delphine ULg et al

in PLoS ONE (2014)

To date, volatile sex pheromones have not been identified in the Coccinellidae family; yet, various studies have suggested that such semiochemicals exist. Here, we collected volatile chemicals released by ... [more ▼]

To date, volatile sex pheromones have not been identified in the Coccinellidae family; yet, various studies have suggested that such semiochemicals exist. Here, we collected volatile chemicals released by virgin females of the multicolored Asian lady beetle, Harmonia axyridis (Pallas), which were either allowed or not allowed to feed on aphids. Virgin females in the presence of aphids, exhibited “calling behavior”, which is commonly associated with the emission of a sex pheromone in several Coleoptera species. These calling females were found to release a blend of volatile compounds that is involved in the remote attraction (i.e., from a distance) of males. Gas Chromatography-Mass Spectrometry (GC-MS) analyses revealed that (–)-β-caryophyllene was the major constituent of the volatile blend (ranging from 80 to 86%), with four other chemical components also being present; β-elemene, methyl-eugenol, α-humulene, and α-bulnesene. In a second set of experiments, the emission of the five constituents identified from the blend was quantified daily over a 9-day period after exposure to aphids. We found that the quantity of all five chemicals significantly increased across the experimental period. Finally, we evaluated the activity of a synthetic blend of these chemicals by performing bioassays which demonstrated the same attractive effect in males only. The results confirm that female H. axyridis produce a volatile sex pheromone. These findings have potential in the development of more specific and efficient biological pest-control management methods aimed at manipulating the behavior of this invasive lady beetle. [less ▲]

Detailed reference viewed: 13 (1 ULg)
Full Text
Peer Reviewed
See detailEffets de deux associations culturales à base de blé sur les populations de pucerons (Homoptera: Aphididae) et d’auxiliaires aphidiphages: étude préliminaire menée en Chine
Chevalier Mendes Lopes, Thomas ULg; Bosquée, Emilie ULg; Honba, David et al

in Entomologie Faunistique = Faunistic Entomology (2014), 67

Crop associations have several advantages when plant species and crop production methods, including harvesting, are well selected. This preliminary study was conducted in the Shandong province (China) to ... [more ▼]

Crop associations have several advantages when plant species and crop production methods, including harvesting, are well selected. This preliminary study was conducted in the Shandong province (China) to better characterize the effect of wheat (Triticum aestivum L.)/oilseed rape (Brassica napus L.) and wheat/pea (Pisum sativum L.) associations on the aphid and aphidophagous beneficial populations. Aphids observed on wheat tillers were significantly more abundant in the pure stand of wheat during the two weeks prior to their population peak, compared with crop associations. Considering the aphidophagous beneficials, significantly more ladybirds were observed in the associations, compared with the pure stand during their abundance peak. Yellow pan traps were also used to assess the diversity and abundance of adult beneficial species. The parasitoid species Aphidius gifuensis (Ashmead) was prevalent. Among predators, Propylea japonica (Thunberg) and Harmonia axyridis (Pallas) were the most abundant species. This study contributes to better understand the potential of crop associations with wheat as a sustainable method to control aphid populations in this region of China. [less ▲]

Detailed reference viewed: 52 (22 ULg)
Peer Reviewed
See detailTuta absoluta (Lepidoptera: Gelechiidae) ability to localize and develop on wild and cultivated solanaceous plant species
Bawin, Thomas ULg; Dujeu, David ULg; Fagan, Maud ULg et al

Conference (2014, December 13)

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important cultivated solanaceous crop plants, including tomatoes and potatoes. Little ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a widespread invasive species damaging economically important cultivated solanaceous crop plants, including tomatoes and potatoes. Little is known about the ability of this microlepidoptera to encounter and develop on alternative wild and agricultural plant species. These plants could provide refuges and have to be identified for more efficient integrated management strategies. In the present study, we assessed the ability of T. absoluta to develop on wild (Solanum nigrum, Atropa belladonna, Datura stramonium) and cultivated (Solanum tuberosum) solanaceous plant species under laboratory conditions. Fitness tests were performed in Petri dishes by isolating single individuals with excised leaf from one of the host plants. We found that Solanum species allowed higher larval survivability and shorter development time (from egg to adult emergency) compared to the other plants. Two choice behavioral assays performed in flying tunnels (S. tuberosum versus another plant) revealed that adult distribution and female oviposition did not differ between Solanum species, which were preferred to the other tested plants. These results appeared to be consistent with survival rates and development times. Because larval survivability depends on the female’s oviposition choice, the hypothesis that host plant choice is influenced by plant volatile organic compounds has to be tested. It can be concluded that Solanum species remain the more suitable hosts for T. absoluta development among the tested plants. Other plant species could be opportunistically colonized with little incidence but care should be taken in these results as genetic variability in insects and plants, as well as plant physiological state, might have an impact on the pest survivabilty. [less ▲]

Detailed reference viewed: 81 (19 ULg)
Peer Reviewed
See detailBelowground Chemical Ecology: The Case of Wireworms
Barsics, Fanny ULg; Delory, Benjamin ULg; Delaplace, Pierre ULg et al

Conference (2014, December 13)

Detailed reference viewed: 10 (4 ULg)
Full Text
See detailImpact of Climate Change on “Aphid - Natural Enemies” Relationship
Boullis, Antoine ULg; Oostrom, Marjolein; Francis, Frédéric ULg et al

Poster (2014, December 12)

While the effects of global atmospheric changes on vegetation and associated insect populations (bottom-up interactions) are increasingly studied, how these gases affect the interactions between insects ... [more ▼]

While the effects of global atmospheric changes on vegetation and associated insect populations (bottom-up interactions) are increasingly studied, how these gases affect the interactions between insects and their natural enemies (top-down interactions) is less clear. As the efficacy of natural enemies is governed largely by behavioral mechanisms, changes in their prey-seeking behavior or the behavior of insect prey defenses can change the dynamics of insect populations. The impact of increases in atmospheric carbon dioxide concentrations on aphid population dynamic is well documented. However, nothing about their chemical ecology is reported in the literature. Aphids are using many chemical signals to communicate with each other or with their environment. For example aphids produce an alarm pheromone to signal the presence of a natural enemy (such as a predator or a parasitoid) in the colony. Moreover, this pheromone is used by natural enemies as a kairomone to locate aphid prey, and is thus at the center of aphid – natural enemies interactions. In this study, the impact of elevated CO2 concentration on the emission of the alarm pheromone in the aphid A. pisum is studied. Using a zNoseTM (Gas chromatograph enabling the fast analyze of the chemical composition of a sample), the kinetic of the EBF emission in real-time is set up for a single individual predated by a coccinellid predator Harmonia axyridis Pallas. This experimentation is done both for aphids reared under ambient atmospheric conditions and for individuals reared under elevated CO2 concentrations. We present the differences in terms of emission dynamic and discuss the potential of these results in terms of biological control. [less ▲]

Detailed reference viewed: 28 (1 ULg)
Full Text
Peer Reviewed
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] (2014), 18(4), 480-487

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 ▲]

Detailed reference viewed: 48 (17 ULg)
Peer Reviewed
See detailWood digestion in lower termites: multidisciplinary approaches based on differential feeding
Bauwens, Julien ULg; Brasseur, Catherine ULg; Tarayre, Cédric ULg et al

Poster (2014, December)

Termites digestive tract and hindgut especially still holds many secrets despites hundreds of years of research. The complexity of the symbiotic microbial community and the contrast of physio-chemical ... [more ▼]

Termites digestive tract and hindgut especially still holds many secrets despites hundreds of years of research. The complexity of the symbiotic microbial community and the contrast of physio-chemical environments found in lower termites paunch are potentially the key point to explain the efficiency of ligno-cellulose digestion. Contribution of advancing technologies accelerates the progress of our knowledge in this field. Here, we present multiple approaches combining old and recent techniques used to highlight the effect of ligno-cellulosic compounds on termite gut and the role of populations from the symbiotic microbial community. Termites Reticulitermes flavipes (Kollar) submitted to various artificial diets showed variations in flagellates populations profile and enzymatic activities. Differential protein expression was investigated using 2D-DIGE MALDI-TOF-TOF and 2D-LC-MS/MS using high resolution orbitrap analyzer. Results from both proteomic experiments tend to support each-other and bring complementary points of view. The gel-free analysis resulted in highly contrasted identification of enzymes involved in ligno-cellulose digestion and metabolism. Finally, differential feeding experiments leaded to in vivo selection of different symbiotic communities. These communities were characterized following some metabolism assays and allowed the cultivation of diverse microbial consortia using media closely related to the respective artificial diets. This work provides relevant data on termite and associated microbial community response to alimentary diets. [less ▲]

Detailed reference viewed: 56 (7 ULg)
Full Text
Peer Reviewed
See detailIncorporate agroecology within research : The on-going story of four young researchers
Hatt, Séverin ULg; Artru, Sidonie ULg; Boeraeve, Fanny ULg et al

in Broadening Scopes on Food, Squeezing Urban Hinterlands (2014, November 04)

Detailed reference viewed: 28 (9 ULg)
Full Text
Peer Reviewed
See detailThe role of olfaction in wireworms: a review on foraging behavior and sensory apparatus
Barsics, Fanny ULg; Haubruge, Eric ULg; Francis, Frédéric ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(4), 524-535

Introduction Integrated management of wireworms (Coleoptera: Elateridae) depends upon approaches applied both above- and belowground, and over several spatial scales. While foraging, these soil pests use ... [more ▼]

Introduction Integrated management of wireworms (Coleoptera: Elateridae) depends upon approaches applied both above- and belowground, and over several spatial scales. While foraging, these soil pests use biotic and abiotic signals to orientate towards target plant organs. Development of efficient techniques for implementation in integrated strategies relies upon improved knowledge of this process. In particular, an important step consists of elucidating the role of volatile organic compounds (VOC), emitted by belowground plant organs, in wireworm chemical ecology. This would have a positive impact on push-pull strategies and varietal selection developed against these insects. Literature In this work, we summarized the available data regarding wireworm foraging behavior as well as variables that should be considered when studying the potential role of plant-produced volatile semiochemicals. This includes CO2 gradients and other host-related cues, temperature, relative humidity and soil moisture, and wireworm physiological stage. We also review what is known of the sensory apparatus of wireworms, since this is involved in every step of the foraging process. Conclusion Some baseline data for studying VOC related wireworm foraging behavior exists. Using it as a tool in applied entomology should result in discovery of the semiochemicals that underpin trophic interactions involving these pests. However, most of the key pest species are not fully described with regards to the parameters detailed here. Obtaining accurate information to fill the current knowledge gaps will be needed in order to devise new integrated management strategies. [less ▲]

Detailed reference viewed: 77 (14 ULg)
Full Text
Peer Reviewed
See detailPlutella xylostella (L.) infestations at varying temperatures induce the emission of specific volatile blends by Arabidopsis thaliana (L.) Heynh
Hien, Truong Thi Dieu ULg; Delory, Benjamin ULg; Brostaux, Yves ULg et al

in Plant Signaling & Behavior (2014)

The effect of combined abiotic and biotic factors on plant volatile organic compound (VOC) emissions is poorly understood. This study evaluated the VOC emissions produced by Arabidopsis thaliana (L.) Col ... [more ▼]

The effect of combined abiotic and biotic factors on plant volatile organic compound (VOC) emissions is poorly understood. This study evaluated the VOC emissions produced by Arabidopsis thaliana (L.) Col-0 subjected to three temperature regimes (17, 22, and 27 °C) in the presence and absence of Plutella xylostella larvae over two time intervals (0–4 and 4–8 h), in comparison to control plants. The analyses of VOCs emitted by Arabidopsis plants were made by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). It was found that certain volatile groups (e.g., alcohols, ketones, aldehydes, and terpenes) are induced by both single factors (temperature or larval infestation) and combined factors (temperature and larvae interactions), whereas other volatile groups (e.g., isothiocyanates [ITCs] and nitrile) were specific to the experimental conditions. ITCs (mainly 4-methylpentyl isothiocyanate) were emitted from plants subjected to larval infestation at 17 and 27 °C after the two time intervals. The proportions of sulfides (mainly dimethyl disulfide) and 4-(methylthio) butanenitrile were significantly higher on herbivore-infested plants at 22 °C compared to the other treatments. Overall, our findings indicate that changes in all experimental conditions caused significant changes to the VOC emissions of Arabidopsis plants. Therefore, the interaction between temperature and larval feeding may represent an important factor determining the variability of volatile emissions by plants subjected to multiple simultaneous factors. [less ▲]

Detailed reference viewed: 22 (13 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 82 (17 ULg)