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See detailInsect Chemical Defense
Laurent, Pascal ULg; Braekman, Jean-Claude; Daloze, Désiré

in Schulz, Stefan (Ed.) The Chemistry of Pheromones and Other Semiochemicals II (2005)

Research on the defensive chemistry of insects during the last decade is reviewed, with special emphasis on non-volatile compounds. The isolation and structure determination of defensive chemicals, of ... [more ▼]

Research on the defensive chemistry of insects during the last decade is reviewed, with special emphasis on non-volatile compounds. The isolation and structure determination of defensive chemicals, of glandular and non-glandular origins, are first discussed, followed by an overview of the synthesis and biological/pharmacological activities of some of them. Biosynthesis has been largely omitted since this topic has been addressed in a recent review. During the period covered, beetles (e.g., coccinellids and chrysomelids) and ants have undoubtedly been the most prolific producers of repellent and/or toxic compounds. This survey also shows that alkaloids are the most frequently encountered defensive compounds in insects. [less ▲]

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See detailInsect fatty acids: A comparison of lipids from three Orthopterans and Tenebrio molitor L. larvae
Paul, Aman ULg; Frederich, Michel ULg; Caparros Megido, Rudy ULg et al

in Journal of Asia-Pacific Entomology (2017), 20(2), 337-340

In order to explore some potential insect sources of food lipids, the lipid compositions of three Orthopterans (Acheta domesticus, Conocephalus discolor and Chorthippus parallelus) were analyzed and ... [more ▼]

In order to explore some potential insect sources of food lipids, the lipid compositions of three Orthopterans (Acheta domesticus, Conocephalus discolor and Chorthippus parallelus) were analyzed and compared with those of Tenebrio molitor larvae. A. domesticus, Co. discolor, Ch. parallelus and T. molitor larvae were found to contain approximately 15%, 13%, 10% and 32% lipids on dry weight, respectively. The lipids from three Orthopterans contain much higher amounts of essential fatty acids than those of T. molitor larvae. The two Orthopterans of the suborder Ensifera i.e., A. domesticus and Co. discolor contain linoleic acid in major quantities, while Ch. parallelus of the suborder Caelifera, contain α-linolenic acid in major quantities. The consumption of linoleic and α-linolenic fatty acid is linked with numerous health promoting effects. The factors that contribute to differences in fatty acid profiles of these insects are being discussed. At last the nutritional parameters including polyunsaturated to saturated and omega 6 to omega 3 fatty acid ratios of these insect lipids are also being discussed to understand the potential role of these lipids in human nutrition. [less ▲]

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See detailInsect pathogenic Aspergillus species in mosquito (Diptera: Culicidae) control compared to Metarhizium anisopliae
Bawin, Thomas ULg

Doctoral thesis (2016)

Many mosquito (Diptera: Culicidae) species are vectors responsible for the transmission of infectious diseases of medical and veterinary importance. Risk for infection considerably increased during the ... [more ▼]

Many mosquito (Diptera: Culicidae) species are vectors responsible for the transmission of infectious diseases of medical and veterinary importance. Risk for infection considerably increased during the last decades due to climate changes and increasing global trade. Vector control is essential for public health management. Integrated pest management is now promoted due to harmful side effects of the chemical insecticides classically used for mosquito control and insect resistance development. This PhD thesis takes part in the selection process of insect pathogenic fungi. Three biological models (Aspergillus clavatus Desmazieres, Aspergillus flavus Link, and Metarhizium anisopliae (Metschnikoff) Sorokin) were selected and investigated regarding their spore insecticidal activity, mode of action, and selectivity. Throughout this scheme, the use of agricultural materials and derivatives in fermentation processes was emphasized. Production methods and insecticidal potential of the fungi were first investigated. On the one hand, the two Aspergillus species were compared to M. anisopliae regarding their spore production when cultured on agro-industrial substrates (white rice and wheat bran) and their insecticidal effect on larvae of the southern house mosquito, Culex quinquefasciatus Say. Our results showed that both substrates are suitable to culture the three insect pathogenic fungal species; but wheat bran-based media increased from 3 to 7-fold the spore yields in solid-state compared to white rice-based media. Also, insect pathogenic Aspergillus species were suggested to yield in similar spore levels in such conditions (in a range of 10^9 spores per g of substrate) and be as virulent against mosquito larvae compared to M. anisopliae. On the other hand, a bioreactor design intended to support large-scale production on agricultural materials by combining the technological advantages of submerged and solid-state fermentations was implemented using A. clavatus. This system allowed facility in recuperation and purification of spores (confined on a packed solid substrate) that retained virulence against mosquito larvae; but also metabolites (contained in a circulating liquid medium) that showed insecticidal effect. The mechanisms responsible for the insecticidal effects of the spores, and their selectivity were then investigated. On the one hand, the invasion routes of A. clavatus spores on mosquito larvae were investigated by light and electron microscopy. Histological observations suggest that toxins secreted by active germinating spores of A. clavatus in the digestive tract altered the larval tissues, leading to necrosis and causing larval death. Fungal proliferation and sporulation then occurred during a saprophytic phase. Such action mode also probably occurred in the case of the two other species. On the other hand, the insecticidal activity of the fungi was assessed against the pea aphid, Acyrthosiphon pisum Linnaeus. Adult A. pisum aphids were susceptible (increased mortality and decreased reproductive potential) to the three fungal species. As a consequence, these fungi would probably be able to infect a broad spectrum of insect hosts (whatever terrestrial or aquatic) once released in the environment. The implications of the results for mosquito control and application strategies are finally discussed, and perspectives for future works proposed. [less ▲]

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See detailInsect pests occurring on Dacryodes edulis (Burseraceae) in rural areas in Gabon
Poligui, René Noël ULg; MOUARAGADJA, ISAAC; Vandereycken, Axel ULg et al

in Neotropical Entomology (2014), 43(4), 322-334

The inventory of pests occurring on Dacryodes edulis (Burseraceae) was carried out in rural areas in Gabon during 2009 and 2010. Yellow traps and visual observations were used to record weekly pests ... [more ▼]

The inventory of pests occurring on Dacryodes edulis (Burseraceae) was carried out in rural areas in Gabon during 2009 and 2010. Yellow traps and visual observations were used to record weekly pests during the tree flowering stage, in five villages. Catches from yellow traps rose to 7,296 and 1,722 insect pests in 2009 and 2010, respectively, whereas records from visual observations corresponded to 1,812 and 171 insect pests in 2009 and 2010, respectively. During both years, abundance from traps and visual monitoring was significantly different between sampling sites (p<0.05). The difference in pests’ diversity between sampling sites was not significant (p>0.05) according to traps, but significant (p≤0.04) according to visual observations in 2010. Mecocorynus loripes Chevrolat (Coleoptera: Cucurlionidae) attacked the stem of D. edulis, while Oligotrophus sp. (Diptera: Cecidomyiidae), Pseudophacopteron serrifer Malenovsky and Burckhardt (Hemiptera: Phacopteronidae), and Selenothrips rubrocinctus Giard (Thysanopera: Thripidae) attacked leaves. Pseudonoorda edulis Maes and Poligui (Lepidoptera: Crambidae) and Lobesia aeolopa Meyrick (Lepidoptera: Tortricidae) infested fruits and inflorescences, respectively. These insects are specifically linked to plant patterns, and their identification provided the first basic information for developing suitable strategies to control pests of D. edulis in Gabon, as well as in neighboring central African countries. [less ▲]

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See detailInsect prenyltransferases: Characterization, roles in insect biology, and evolution
Cusson, Michel; Vandermoten, Sophie ULg; Barbar, Aline et al

Conference (2009, December)

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See detailInsect sting over gymnosperm from the Albian deposits of Teruel province (NE Spain)
Estévez-Gallardo, Pablo; Sender, Luis Miguel; Cascales - Miñana, Borja ULg et al

in Cascales - Miñana, Borja; Villanueva-Amadoz, Uxue; Diez, José B. (Eds.) Proceedings of the II Agora Paleobotanica Meeting (Abstract book) (2013, July)

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See detailLes insectes aquatiques du ru de Targnon (Commune de Theux)
Dethier, Michel; Dopagne, Claude ULg

in Natura Mosana (2001), 54(4), 67-76

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See detailInsectes consommés par l'Homme en Afrique occidentale francophone
Tchibozo, Séverin; Malaisse, François ULg; Mergen, Patricia

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2016), 40(2), 105-114

Les insectes sont consommés depuis des temps ancestraux par les habitants des divers pays d’Afrique de l’Ouest. Les données ont été collectées au Niger, Mali, Guinée Conakry, Burkina Faso et au Bénin ... [more ▼]

Les insectes sont consommés depuis des temps ancestraux par les habitants des divers pays d’Afrique de l’Ouest. Les données ont été collectées au Niger, Mali, Guinée Conakry, Burkina Faso et au Bénin. Parmi les espèces inventoriées, les termites ailés, les criquets et les chenilles sont les plus utilisées dans l’alimentation humaine. Les insectes comestibles pourraient demain remplacer la viande et offrir une solution pour la sécurité alimentaire. Leur élevage produit peu de gaz à effet de serre, à l’inverse de celui des bovins. Les insectes contiennent des éléments nutritifs pour l’Homme. Ceux qui sont riches en protéines, fer et vitamine A, constitueraient une solution pour réduire les déficiences nutritionnelles aiguës des enfants de moins de cinq ans. Afin d’atteindre ce but, il est important de bien connaître les espèces concernées et d’en faire un inventaire aussi bien sur le terrain, que sur les marchés ou encore les élevages. Bien connaître la biologie des espèces ainsi que leur habitat, ainsi que par exemple établir la liste des plantes hôtes est essentiel. Ceci afin de bien évaluer les conditions d’élevage et la faisabilité pour avoir un impact réel et efficace sur les problèmes de sécurité alimentaire, tout en permettant une activité génératrice de revenus pour les populations locales, mais aussi des perspectives de commercialisation dans les pays industrialisés. [less ▲]

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See detailLes insectes dans l'agriculture
Hatt, Séverin ULg; Francis, Frédéric ULg

Conference given outside the academic context (2015)

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See detailLes insectes et autres animaux dans nos bibliothèques, archives et collections: identification, biologie, prévention et élimination
Mignon, Jacques ULg

Scientific conference (2012, January 19)

Principaux critères d'identification et biologie des principaux insectes et rongeurs observés en bibliothèques et autres collections. Symptômes et dégâts observés. Prévention et lutte intégrée par le ... [more ▼]

Principaux critères d'identification et biologie des principaux insectes et rongeurs observés en bibliothèques et autres collections. Symptômes et dégâts observés. Prévention et lutte intégrée par le froid, l'anoxie et le vide. [less ▲]

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See detailInsectes et communication
Arnaud, Ludovic; Detrain, Claire; Gaspar, Charles et al

in Journal des Ingénieurs (Le) (2003), 87

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See detailInsectes et communication chimique - Sémiochimiques et olfaction
Verheggen, François ULg

Conference (2011, March 15)

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s ... [more ▼]

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s'intéresse au décriptage de ce mode de communication, dont le maitre d'œuvre est le système olfactif des insectes, où antennes et sensilles supportent toute la machinerie physiologique nécessaire à la perception des phéromones et coactones. Pour comprendre le language chimique employé par un insecte, de nombreux outils ont été développés, permettant (1) l'échantillonnage des molécules organiques produites par un insecte, (2) la séparation, la quantification et l'identification des différents constituants du mélange phéromonal,(3) l'étude de la perception par le système olfactif de l'insecte et (4) l'étude du comportement d'un individu mis en présence d'un potentiel bouquet phéromonal ou de l'un de ses constituants. De nombreuses phéromones et coactones ont déjà trouvé le chemin de la valorisation dans le domaine de la protection des cultures. Bien que les insectes d'intérêt agronomique soient les plus largement étudiés, les sémiochimiques employés par d'autres groupes d'insectes font l'objet de nouvelles recherches, avec notamment l'émergence de l'entomologie criminelle [less ▲]

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See detailInsectes et communication chimique - Techniques et méthodes en écologie chimique
Verheggen, François ULg

Conference (2011, March 17)

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s ... [more ▼]

Les insectes communiquent avec leurs semblables et avec leur environnement par le biais de molécules organiques informatives nommées sémiochimiques. L'écologie chimique est la branche de l'écologie qui s'intéresse au décriptage de ce mode de communication, dont le maitre d'œuvre est le système olfactif des insectes, où antennes et sensilles supportent toute la machinerie physiologique nécessaire à la perception des phéromones et coactones. Pour comprendre le language chimique employé par un insecte, de nombreux outils ont été développés, permettant (1) l'échantillonnage des molécules organiques produites par un insecte, (2) la séparation, la quantification et l'identification des différents constituants du mélange phéromonal,(3) l'étude de la perception par le système olfactif de l'insecte et (4) l'étude du comportement d'un individu mis en présence d'un potentiel bouquet phéromonal ou de l'un de ses constituants. De nombreuses phéromones et coactones ont déjà trouvé le chemin de la valorisation dans le domaine de la protection des cultures. Bien que les insectes d'intérêt agronomique soient les plus largement étudiés, les sémiochimiques employés par d'autres groupes d'insectes font l'objet de nouvelles recherches, avec notamment l'émergence de l'entomologie criminelle [less ▲]

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See detailInsectes ravageurs: Protection des grains stockés
Mignon, Jacques ULg; Haubruge, Eric ULg; Gaspar, Charles

in Agricontact (1996), 287

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See detailLes insectes, des aliments?
Blecker, Christophe ULg

Conference (2013, March 28)

Detailed reference viewed: 17 (1 ULg)
See detailLes insectes, des aliments?
Blecker, Christophe ULg

Conference (2014, May 02)

Detailed reference viewed: 20 (4 ULg)