References of "Francis, Frédéric"
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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 detailNew alternatives to chemical pesticides: deciphering the action mechanisms of lipid based plant elicitors via complementary biophysical and biological approaches.
Nasir, Mehmet Nail ULg; Polo Lozano, Damien ULg; Luzuriaga Loaiza, Walter ULg et al

Poster (2014, February)

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among ... [more ▼]

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among biopesticides, elicitor molecules which are able to trigger immune defense responses in plants are one of the most promising options. Although numerous elicitors have been discovered, the mechanisms involved in the perception, by plants, of only a few molecules have been identified. These elicitors usually interact with proteic receptors but we have recently shown that they may also act on the lipid phase of the plasma membrane. This project first aims to improve our understanding of the molecular mechanisms involved in the recognition of specific lipid based elicitors (LBE). On that basis, the FIELD project will contribute to the design and the development of innovative compounds derived natural LBE. A multi-disciplinary approach, based on chemistry, bio-physics, bio-chemistry, and phytopathology will be followed by a consortium of different research groups from Gembloux Agro-Bio Tech in close collaboration with teams from foreign institutions. [less ▲]

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See detailCombination of Genomic and Proteomic Approaches to Characterize the Symbiotic Population of the Banana Aphid (Hemiptera: Aphididae)
De Clerck, Caroline ULg; Tsuchida, Tsutomu; Massart, Sébastien ULg et al

in Environmental Entomology (2014)

Aphids are known to live in symbiosis with speciÞc bacteria called endosymbionts that have positive or negative impacts on their hosts. In this study, six banana aphid (Pentalonia nigronervosa Coquerel ... [more ▼]

Aphids are known to live in symbiosis with speciÞc bacteria called endosymbionts that have positive or negative impacts on their hosts. In this study, six banana aphid (Pentalonia nigronervosa Coquerel) strains from various geographical origins (Gabon, Madagascar, and Burundi) were screened to determine their symbiotic content, using complementary genomic (16S rDNA sequencing and speciÞc polymerase chain reaction) and proteomic (two-dimensional difference gel electrophoresis coupled with protein identiÞcation by matrix assisted laser desorption-ionization time-of-ßight mass spectrometry) approaches. Despite the geographical heterogeneity, the combined methods allowed us to identify the same two symbionts in the six aphids strains tested: Buchnera aphidicola and Wolbachia. Although B. aphidicola is found in almost all aphid species, the systematic presence of Wolbachia in banana aphids is particularly interesting, as this bacterium usually has a low prevalence in aphid species. Phylogenetic analyses showed that the Wolbachia sp. strain found in P. nigronervosa was very similar to the strain present in aphids of the genus Cinara, known to have developed a strong and long-term symbiotic association with Wolbachia. The high level of asexual reproduction in P. nigronervosa could be linked to the presence of Wolbachia, but its prevalence also suggests that this symbiotic bacterium could play a more essential role in its aphid host. [less ▲]

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See detailTechnologie de production de masse d’insectes - INSECTECH
Richard, Gaetan ULg; Hance, Thierry; Fauconnier, Marie-Laure ULg et al

Report (2014)

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See detailIsolation of an amylolytic chrysophyte, Poterioochromonas sp. from the digestive tract of the termite R. santonensis
Tarayre, Cédric ULg; Bauwens, Julien ULg; Brasseur, Catherine ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(1),

The aim of this work was the isolation and cultivation of amylolytic protists living in the digestive tract of the termite Reticulitermes santonensis (Feytaud). A chrysophyte identified as ... [more ▼]

The aim of this work was the isolation and cultivation of amylolytic protists living in the digestive tract of the termite Reticulitermes santonensis (Feytaud). A chrysophyte identified as Poterioochromonas sp. was isolated in a special medium containing rice grains as a source of carbon and nitrogen. Then, the protist was grown in a medium containing starch as a carbon source, tryptone, and a phosphate buffer at different pH values (5, 6 and 7). Yeast extract was added or not. Ciprofloxacin was used to avoid the bacterial development. Other antibiotics were also tested but showed an inhibitive effect on the growth of Poterioochromonas sp. Yeast extract allowed reaching 1.9 (pH 5), 2.3 (pH 6) and 2.2 (pH 7) times higher final cell concentrations, and 2.8 (pH 5), 2.8 (pH 6) and 2.2 (pH 7) times higher biomass yields. The starch concentration did not decrease in the medium until 3 and 4 days of culture, with and without yeast extract, respectively. Eight days of culture were necessary for hydrolyzing the starch completely, with and without yeast extract. Maltose and maltotriose were detected in the culture media and were hydrolyzed progressively. Maximal maltose concentrations were 0.68, 0.66 and 0.51 g.l-1 in the medium containing yeast extract. Maltotriose concentrations were only 0.17, 0.14 and 0.12 g.l-1. Other glucose oligomers were also detected but in lower quantities. It was determined that the protist developed a weak amylase activity, particularly at a weakly acidic pH (5-6). Such a pH also allowed a better growth of the protist. A maximal amylase activity of 112 nkat.l-1 was measured with yeast extract at pH 5. No other enzymatic activity (protease, cellulase or xylanase) was detected except amylase. The degradation products of starch which were obtained by enzymatic hydrolysis allow the identification of α-amylase, amyloglucosidase and possibly β-amylase activities. [less ▲]

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See detailVOC emissions and protein expression mediated by the interactions between herbivorous insects and Arabidopsis plant. A review
Hien, Truong Thi Dieu ULg; Heuskin, Stéphanie ULg; Delaplace, Pierre ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2014), 18(3), 455-464

Herbivorous insects, such as phloem-sap feeders and chewers, induce resistance response in plants. There is a long-standing hypothesis that herbivores increase the emission of volatile organic compounds ... [more ▼]

Herbivorous insects, such as phloem-sap feeders and chewers, induce resistance response in plants. There is a long-standing hypothesis that herbivores increase the emission of volatile organic compounds (VOCs) in the Arabidopsis plant model. However, most works were restricted to the study of the regulation of plant VOC emissions and only in some cases to the effects of insects on such emissions. Often these investigations do not establish a link between quantitative and qualitative emission of plant VOCs with actual damages caused by insects. Moreover, information remain limited about the processes that occur at the protein level encoded of the host plant under stress conditions. Here, we briefly summarize the effects of specific chewing and phloem-sap feeding insects on the emission of VOCs by Arabidopsis thaliana Col-0, and review some predictions about pathogenesis-related proteins, based on current evolutionary hypotheses. Further investigation of the effects of herbivorous insects on VOC emissions and protein expression is expected to improve our knowledge about their patterns and functions in plant responses to stresses. [less ▲]

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See detailRisque allergique des insectes en alimentation humaine
Mairesse, M; Debaugnies, F; Doyen, V et al

in Revue Française d'Allergologie (2014), 54(3), 288

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See detailInfestation Level Influences Oviposition Site Selection in the Tomato Leafminer Tuta absoluta (Lepidoptera: Gelechiidae)
Bawin, Thomas ULg; De Backer, Lara ULg; Dujeu, David ULg et al

in Insects (2014), 5

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a devastating pest that develops principally on solanaceous plants throughout South and Central America and Europe. In this study, we ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a devastating pest that develops principally on solanaceous plants throughout South and Central America and Europe. In this study, we tested the influence of three levels of T. absoluta infestations on the attraction and oviposition preference of adult T. absoluta. Three infestation levels (i.e., non-infested plants, plants infested with 10 T. absoluta larvae, and plants infested with 20 T. absoluta larvae) were presented by pairs in a flying tunnel to groups of T. absoluta adults. We found no differences in terms of adult attraction for either level of infestations. However, female oviposition choice is influenced by larvae density on tomato plants. We discuss the underlying mechanisms and propose recommendations for further research [less ▲]

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See detailMicroorganism-associated semiochemicals reduce the size of aphid populations in potato fields
Alabi, Taofic ULg; Brostaux, Yves ULg; Grigorescu, Alina ULg et al

in Revue des Régions Arides (2014), 35

The chemical cues released by many insect species, including agricultural pests, are used by predators and parasitoids to locate their prey or host. For instance, aphids excrete honeydew, which contains ... [more ▼]

The chemical cues released by many insect species, including agricultural pests, are used by predators and parasitoids to locate their prey or host. For instance, aphids excrete honeydew, which contains bacteria that produce semiochemicals. Ladybeetles and hoverflies use these semiochemicals to locate the colonies of prey aphid species. One bacterium (Staphylococcus sciuri) has been identified in the honeydew of the pea aphid, Acyrthosiphon pisum. This bacterium is responsible for the production of kairomonal substances, which guide hoverflies to aphid colonies. In the present study, we cultivated S. sciuri, and used solid-phase microextraction (SPME) to confirm the ability of this bacterium to produce 3-methyl-2-butenal and 3-methyl-2-butenoic acid, which previous studies have demonstrated as being the two semiochemicals that exhibit kairomonal activity. We subsequently conducted field experiments to evaluate the efficiency of two solutions as biological products to control aphid populations inhabiting potato plants; the first solution contained a suspension of living S. sciuri, and the second solution contained a mixture of the two semiochemicals produced by this bacterium. While the semiochemical solution did not lead to a significant reduction in aphid number, potato plants treated with the S. sciuri solution were infested with 28% less aphids compared to untreated plants. This study demonstrates the potential of using naturally occurring bacteria as a form of biological control of aphid infestations in agricultural management. [less ▲]

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See detailWhole-genome sequence of Serratia symbiotica strain CWBI-2.3T, a free-living symbiont of the Black Bean Aphid Aphis fabae
Foray, Vincent; Grigorescu, Alina ULg; Sabri, Ahmed et al

in Genome Announcements (2014), 2(4),

The gammaproteobacterium Serratia symbiotica is one of the major secondary symbionts found in aphids. Here, we report the draft genome sequence of S. symbiotica strain CWBI-2.3T, previously isolated from ... [more ▼]

The gammaproteobacterium Serratia symbiotica is one of the major secondary symbionts found in aphids. Here, we report the draft genome sequence of S. symbiotica strain CWBI-2.3T, previously isolated from the black bean aphid Aphis fabae. The 3.58-Mb genome sequence might provide new insights to understand the evolution of insect-microbe symbiosis. [less ▲]

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See detailStudy of the potentiality of insect breeding system for human food in Cambodia (Ratanakiri province)
Caparros Megido, Rudy ULg; Alabi, Taofic ULg; Nieus, Clément et al

Conference (2014)

The main purpose of this work was to optimize a cheap cricket breeding production for local farmers based on unused wild resources. Cricket development (Teleogryllus testaceus (Walker)) was compared ... [more ▼]

The main purpose of this work was to optimize a cheap cricket breeding production for local farmers based on unused wild resources. Cricket development (Teleogryllus testaceus (Walker)) was compared according to seven diets composed of different ratio of aerial parts of taro, young cassava leaves, young cashew leaves, brown rice flour (with or without banana slices) and between the traditionally used chicken feed diet. Cricket mortality was low on all diets (<10 %) excepted on the two cashew-based diets (>90 %). Mean adult body mass was significantly higher on chicken feed diet and on the two cassava-based diet than on the other. Moreover, protein percentage in cassava-feed crickets was similar with this of wild crickets. As each villager grows cassava for their tubers without using the leaves, this free available resource could be used to rear crickets in order to contribute to the reduction of protein deficiency and create new source of incomes for local farmers. [less ▲]

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See detailConsumer acceptance of insect-based products
Caparros Megido, Rudy ULg; Gierts, Chloé; Blecker, Christophe ULg et al

Conference (2014)

In this study, sociocultural and food formulation aspects related to edible insects were investigated on Belgian consumers. Hedonic tests were realized to assess the acceptability of insect-based burgers ... [more ▼]

In this study, sociocultural and food formulation aspects related to edible insects were investigated on Belgian consumers. Hedonic tests were realized to assess the acceptability of insect-based burgers and insect-based breads. In the first experiment, four burgers (beef, lentil, beef/insect and lentil/insect) were presented to the participants. In the second experiment, entire mealworms, mealworm bread and mealworm crepes were presented to the participants. No difference of appreciations was noticed between a beef and a beef/insect burger and between a lentil and a lentil/insect burger. Crepes made of mealworm flour were slightly preferred in comparison with mealworm bread and entire mealworms. These results confirm that shape and appearance but also popularization and information spreading are key conditions in the acceptation of insect products in western countries and that insects will preferentially be consumed, in the future, if they are presented in an invisible way and associated with familiar flavors. [less ▲]

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See detailAphid honeydew: An arrestant and a contact kairomone for Episyrphus balteatus (Diptera: Syrphidae) larvae and adults
Leroy, Pascal; Almohamad, Raki; Attia, Sabrine et al

in European Journal of Entomology (2014), 111(2), 237-242

Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue ... [more ▼]

Predator searching efficiency increases in response to a variety of environmental cues associated with its prey. The sugary excretion of aphids (honeydew) has been found to act as a prey-associated cue for many aphid natural enemies. In the present study, the honeydew excreted by Acyrthosiphon pisum (Harris) was identified as an arrestant and a contact kairomone for young larvae and adults of a common predatory hoverfly, Episyrphus balteatus (De Geer) (Diptera: Syrphidae). First and second instar larvae increased their foraging behaviour in the honeydew-treated area. When plants were sprayed with crude honeydew, the speed of movement of female E. balteatus was significantly higher than in controls, resulting in a longer period of time spent on treated plants and laying eggs. We conclude that the honeydew excreted by A. pisum induces searching behaviour and acts as and arrestant not only for adults but also for young E. balteatus larvae. [less ▲]

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See detailRole of larval host plant experience and solanaceous plant volatile emissions in Tuta absoluta (Lepidoptera: Gelechiidae) host finding behavior
Caparros Megido, Rudy ULg; De Backer, Lara; Ettaïb, Refki et al

in Arthropod-Plant Interactions (2014)

The tomato leafminer, Tuta absoluta (Lepi- doptera: Gelechiidae), is considered to be a major pest that damages tomato (Solanum lycopersicum L; Solanaceae) crops in South American, European, and ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepi- doptera: Gelechiidae), is considered to be a major pest that damages tomato (Solanum lycopersicum L; Solanaceae) crops in South American, European, and Mediterranean countries. This insect species is polyphagous (i.e., feeds on many types of food); hence, it could also develop on other cultivated host plants, principally solanaceous plants, such as potato (S. tuberosum L.; Solanaceae) and eggplant (S. melongena L.; Solanaceae). Therefore, we tested the hypothesis that host plant choice by adult T. absoluta is influenced by plant volatile organic compounds and larval host plant experience. One tomato cultivar (cv.) ‘Money- maker’ and three potato cv. ‘Charlotte’ ‘Bintje,’ and ‘Nicola’ were tested. Using a flying tunnel, we observed that females reared on tomato preferred flying toward tomato and, to a lesser extent, potato cv. ‘Charlotte.’ These preferences might be explained by the high release of terpenes by these two plants. When conducting oviposition choice assays, we found no preference between tomato and potato in the number of eggs laid by females that had been previously reared on either host plant. This study indicates that the host finding behavior of T. absoluta is mediated by solanaceous volatiles, while oviposition behavior appears to depend on additional stimuli. These results provide baseline information for use in the development of new control strategies against T. absoluta using semiochemicals and plant breeding. [less ▲]

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See detailInventaire préliminaire des termites (Isoptera) du plateau des Batékés en République Démocratique du Congo
Kifukieto, Carmel; Deligne, Jean; Kachaka, Claude et al

in Entomologie Faunistique = Faunistic Entomology (2014), 67

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See detailOptimization of cricket breeding production system for human food in Ratanakiri province (Cambodia)
Caparros Megido, Rudy ULg; Alabi, Taofic ULg; Nieus, Clément et al

Poster (2014)

Despite many natural resources, Cambodia is considered as a relatively poor country with a Gross National Income per capita averaging about 880 USD in 2012. Annâdya project in the Ratanakiri province ... [more ▼]

Despite many natural resources, Cambodia is considered as a relatively poor country with a Gross National Income per capita averaging about 880 USD in 2012. Annâdya project in the Ratanakiri province (Cambodia) aims to improve the food security and nutrition of smallholder households by introducing and facilitating the adoption of productive and environmentally sustainable agricultural technologies. The main purpose of this work was to optimize a cheap cricket breeding production system for local farmers to contribute to the reduction of protein deficiency and to create new source of incomes. Cricket development, Teleogryllus testaceus (Walker), was compared between seven diets composed of different ratio of aerial parts of taro, young cassava leaves, young cashew leaves, brown rice flour (with or without the addition of banana slices) and between the traditionally used chicken feed diet. Cricket mortality was relatively low on all diets (<10 %) excepted on the two cashew-based diets where mortality achieves 90 %. Mean adult body mass of the cricket was significantly higher on control diet (chicken feed) and on the two cassava-based diet (80% of cassava leave flour, 20% of brown rice with or without banana slices) than on the other diets (F = 20.87, P<0.001). The nutritional analyzes of the seven diets shows that the ideal diet should contain 19% protein, 5-6% fat, and a percentage of carbohydrates as high as possible. While the cricket mass body gain seems to be proportional to the carbohydrate content of the diet, the use of older cassava leaves, more rich in carbohydrates than the younger ones, is an interesting solution to substitute relatively expensive brown rice and banana slices also consumed by local population. In the future, consideration should be given to the adjustment of cassava leave maturity in function of the cricket growth stage as it is already done with chicken feed in Thai cricket farms. [less ▲]

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See detailSituation and perspective of entomophagy in Kinshasa
Nsevolo, Papy; Caparros Megido, Rudy ULg; Blecker, Christophe ULg et al

Poster (2014)

Eating edible insects in Republic Democratic of Congo is a tradition for centuries but a lack of knowledge remains about an actualized inventory of species consumed in the country. Moreover, a rigorous ... [more ▼]

Eating edible insects in Republic Democratic of Congo is a tradition for centuries but a lack of knowledge remains about an actualized inventory of species consumed in the country. Moreover, a rigorous taxonomic matching of the used vernacular name of edible insects and a precise characterization of the sector of entomophagy are still needed. According to our studies focused on the city of Kinshasa, 14 edible species were inventoried as regularly consumed. They belong respectively and by degree of importance to the Lepidoptera (46.7%), Isoptera (18.6%), Orthoptera (17.6%), Coleoptera (9.7%) and Hymenoptera (3.7%) orders. Generally 80.0% of the Kinshasa population consumes at least one species of insects 5 days per month. The key peoples in the edible insect sector are mostly women. The incomes generated by this activity contribute to the well being of households, to reduce poverty and food insecurity in the capital Kinshasa. Future studies should focus on sustainable ways of harvesting wild populations, the use of improved conservation practices, the enhancement of cottage industries for farming insects and the development of economically feasible ways of mass-rearing edible species. [less ▲]

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See detailSix pattes et si délicieux : Les insectes dans nos assiettes
Caparros Megido, Rudy ULg; Haubruge, Eric ULg; Francis, Frédéric ULg

Book published by Les presses agronomiques de Gembloux (2014)

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