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See detailLes insectes: Jardiniers du diable, templier de Lucifer
Verheggen, François ULg

Conference given outside the academic context (2013)

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See detailFirst Evidence of a Volatile Sex Pheromone in Harmonia axyridis (Pallas)
Fassotte, Bérénice ULg; Fischer, Christophe ULg; Durieux, Delphine ULg et al

Poster (2013, October)

Until now, no volatile sex pheromone has been highlighted in Coccinellidae but various studies have suggested the existence of such molecules. In the present work, we have sampled volatile organic ... [more ▼]

Until now, no volatile sex pheromone has been highlighted in Coccinellidae but various studies have suggested the existence of such molecules. In the present work, we have sampled volatile organic compounds released in the headspace of virgin females in the multicolored Asian ladybeetle, Harmonia axyridis (Pallas), that were either allowed or not to feed on pea aphids (Acyrthosiphon pisum Harris). When fed on aphids, virgin females showed a stereotypical “calling behavior”, commonly associated with the emission of a sex pheromone in several Coleoptera species. Behavioral assays conducted with calling females in a four-arm olfactometer demonstrated that the blend of released volatile compounds was attractive at a distance for males, but not for other females. The headspace of virgin females that were not previously fed with aphids was not attractive for either sex. GC-MS analyses revealed the presence of five compounds in the volatile blend: (–)-β-caryophyllene, β-elemene, methyl-eugenol, α-humulene and α-bulnesene. Subsequently, we have collected and quantified the constituents from the blend over a period of 9 days after exposure to aphids. All five compounds were produced exclusively after feeding virgin females with aphids, and their quantity significantly increased during the whole period of collection. (–)-β-caryophyllene was found to be the major constituent, representing between 80 and 86 % of the total blend. All these results could promote the development of more specific and efficient management methods to manipulate the movements of this invasive ladybeetle and to reduce its negative impacts on biodiversity. [less ▲]

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See detailThe Multicoloured Asian Ladybird, invasive or not in agroecosystems ?
Vandereycken, Axel ULg; Durieux, Delphine ULg; Fassotte, Bérénice ULg et al

Poster (2013, September 10)

The Multicoloured Asian Ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is known to thrive principally in shrubby and arboreal habitats. Its occurrence in agroecosystems remains poorly ... [more ▼]

The Multicoloured Asian Ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is known to thrive principally in shrubby and arboreal habitats. Its occurrence in agroecosystems remains poorly documented. This study focuses on the occurrence of this exotic species and its seasonal abundance in various field crops. The abundance of adults and larvae of H. axyridis was evaluated over a four-year period, from 2009 to 2012, in four important agronomical crops (wheat, corn, broad bean and potato) in Belgium. A total of 28 aphid predator species were observed including 14 coccinellid species, 13 hoverfly species and one lacewing species. H. axyridis is present and reproduces in all of the four crops studied, with the largest numbers recorded in corn and broad bean crops. In corn, H. axyridis numbers were found to increase over the four inventoried year, reaching 86% of the aphid predators in 2012, while it represented only 15% in 2009. H. axyridis was not always recorded where aphids were abundant, e.g. aphids were abundant on wheat where no H. axyridis were recorded. H. axyridis starts reproducing after the peak in aphid population, suggesting that H. axyridis is able to complete its development by feeding on alternative prey such as larvae and pupae of the same and other species of ladybird and other aphidophagous species. H. axyridis is often considered to be bivoltine but it only completes one generation per year in field crops. The second generation generally develops late in the season in other habitats. Harmonia axyridis is an invasive and an intraguild predator present in high quantities in some specific crops. In these crops, H. axyridis could negatively impact on population of native species due to IGP observed in several other studies. [less ▲]

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See detailFirst evidence of a volatile sex pheromone in the invasive Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)
Fassotte, Bérénice ULg; Fischer, Christophe ULg; Durieux, Delphine ULg et al

Conference (2013, September 10)

Until now, volatile sex pheromone have not been identified in the Coccinellidae, although various studies have suggested the existence of such molecules. In this work, we have sampled volatile organic ... [more ▼]

Until now, volatile sex pheromone have not been identified in the Coccinellidae, although various studies have suggested the existence of such molecules. In this work, we have sampled volatile organic compounds released in the headspace of virgin females of the multicolored Asian ladybeetle, Harmonia axyridis (Pallas), that were either allowed or not to feed on pea aphids (Acyrthosiphon pisum Harris). When fed on aphids, virgin females showed a stereotypical “calling behavior”, commonly associated with the emission of a sex pheromone in several Coleoptera species. Behavioral assays conducted with calling females in a four-arm olfactometer demonstrated that the blend of released volatile compounds was attractive for males, but not for other females. The headspace of virgin females that were not previously fed with aphids was not attractive for either sex. GC-MS analyses revealed the presence of five compounds in the volatile blend: (–)-β-caryophyllene, β elemene, methyl-eugenol, α-humulene and α-bulnesene. Subsequently, we have collected and quantified the constituents from the blend over a period of 9 days after exposure to aphids. All five compounds were produced exclusively after feeding virgin females with aphids, and their quantity significantly increased during the whole period of collection. (–)-β-caryophyllene was found to be the major constituent, representing between 80 and 89 % of the total blend. These results could promote the development of more specific and efficient management methods to manipulate the movements of this invasive ladybeetle and to reduce its negative impacts on biodiversity. [less ▲]

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See detailLes vers à soie malgaches - Enjeux écologiques et socio-économiques
Verheggen, François ULg; Bogaert, Jan ULg; Haubruge, Eric ULg

Book published by Presses agronomiques de Gembloux (2013)

Cet ouvrage reflète les réalisations et activités scientifiques du projet de coopération universitaire « Gestion et valorisation durable du ver à soie endémique Borocera cajani en milieu forestier dans la ... [more ▼]

Cet ouvrage reflète les réalisations et activités scientifiques du projet de coopération universitaire « Gestion et valorisation durable du ver à soie endémique Borocera cajani en milieu forestier dans la région d’Antananarivo » financé par la Commission Universitaire pour le Développement (CUD). Ce projet de recherche est le fruit d’une collaboration étroite entre le Département des Eaux et Forêts de l’école Supérieure des Sciences Agronomiques de l’Université d’Antananarivo, l’Université de Liège et l’Université Libre de Bruxelles. Une première section de l’ouvrage porte sur les aspects biologiques et écologiques des vers à soie endémiques de Madagascar – avec l’accent sur le landibe (Borocera cajani) – notamment sa morphologie, l’estimation de son abondance dans l’aire étudiée, la dynamique de ses populations, ses interactions avec ses plantes hôtes, son comportement d’alimentation et son développement larvaire. La deuxième section étudie les dimensions écologiques et botaniques de l’habitat des vers à soie, à savoir les formations de tapia (Uapaca bojeri), principalement à travers les aspects sylvicoles et botaniques, les causes et indicateurs de dégradation, la discussion autour de sa dénomination, la diversité floristique, la régénération et l’inventaire des ressources sauvages comestibles et leurs caractéristiques chimiques. La troisième section renseigne sur l’état et la valorisation de la filière soie et couvre une diversité d’approches, allant des connaissances et savoir-faire des communautés locales au rôle de la soie dans l’économie rurale. Le contexte socio-institutionnel ainsi que les interactions entre les acteurs concernés par la filière complètent ce volet. L’ouvrage contient 21 contributions scientifiques, rédigées par 34 auteurs, dont certains ont déjà fait l’objet d’une publication dans une revue internationale. Le volume a été composé sous la direction scientifique de François J. Verheggen, Jan Bogaert et éric Haubruge, enseignants à Gembloux Agro-Bio Tech (Université de Liège). Il s’adresse à tous ceux qui s’intéressent à la coopération universitaire et/ou aux recherches écologiques, entomologiques et sociologiques dans un contexte malgache. [less ▲]

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See detailDiversity of forensic rove beetles (Coleoptera, Staphylinidae) associated with decaying pig carcass in a forest biotope
Dekeirsschieter, Jessica ULg; Frederickx, Christine ULg; Verheggen, François ULg et al

in Journal of Forensic Sciences (2013)

Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession. So far, little information is available on the postmortem colonization by beetles and the ... [more ▼]

Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession. So far, little information is available on the postmortem colonization by beetles and the decomposition process they initiate under temperate biogeoclimatic countries. These beetles have however been referred to as being part of the entomofaunal colonization of a dead body. Forensic entomologists need increased databases detailing the distribution, ecology and phenology of necrophagous insects, including staphylinids (Coleoptera, Staphylinidae). While pig carcasses are commonly used in forensic entomology studies to surrogate human decomposition and to investigate the entomofaunal succession, very few works have been conducted in Europe on large carcasses. Our work reports the monitoring of the presence of adult rove beetles (Coleoptera, Staphylinidae) on decaying pig carcasses in a forest biotope during four seasons (spring, summer, fall and winter). A total of 23 genera comprising 60 species of rove beetles were collected from pig carcasses. [less ▲]

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See detailOccurrence of aphid predator species in both organic and conventional corn and broad bean
Vandereycken, Axel ULg; Joie, Emilie ULg; Francis, Frédéric ULg et al

in Entomologie Faunistique = Faunistic Entomology (2013), 66

Organic farming has been suggested to enhance beneficial species abundance and diversity in agrosystem habitats. In this study, the abundance of aphid predators was compared in organic and conventional ... [more ▼]

Organic farming has been suggested to enhance beneficial species abundance and diversity in agrosystem habitats. In this study, the abundance of aphid predators was compared in organic and conventional corn and broad bean fields during a two-year inventory. In both farming strategies, there were no differences between species diversity. Five aphid predator species were mainly observed: Coccinella septempunctata L. 1758 (Coleoptera: Coccinellidae), Propylea quatuordecimpunctata (L. 1758) (Coleoptera: Coccinellidae), Harmonia axyridis Pallas 1773 (Coleoptera: Coccinellidae), Chrysoperla carnea (Stephens 1836) (Neuroptera: Chrysopidae) and Episyrphus balteatus (De Geer 1776) (Diptera: Syrphidae). Differences in abundance of aphidophagous species between conventional and organic crop fields were observed even if not always in favour of the latter condition. The abundance of the five above- mentioned aphidophagous species varied for the most part according to almost all the observed parameters, including sampled year, crop and agricultural practices. In conclusion, our findings do not support organic practices in corn and broad bean as key options to increase the biodiversity and abundance of aphid natural enemies. [less ▲]

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See detailElectrophysiological and behavioural responses of Thanatophilus sinuatus F. (Coleoptera: Silphidae) to selected cadaveric volatile organic compounds
Dekeirsschieter, Jessica ULg; Frederickx, Christine ULg; Lognay, Georges ULg et al

in Journal of Forensic Sciences (2013)

Soon after death, carcasses release volatile chemicals that attract carrion insects including Silphidae. Nevertheless, it is not known which chemical cues are involved in the attractiveness of the carcass ... [more ▼]

Soon after death, carcasses release volatile chemicals that attract carrion insects including Silphidae. Nevertheless, it is not known which chemical cues are involved in the attractiveness of the carcass. So far, little information is available on the chemical ecology of carrion beetles, particularly concerning the subfamily of Silphinae. The biological role of selected cadaveric volatile organic compounds including: dimethyldisulfide (DMDS), butan-1-ol, n-butanoic acid, indole, phenol, p-cresol, putrescine, and cadaverine on the silphine species, Thanatophilus sinuatus Fabricius, was investigated by using both electrophysiological and behavioural techniques. Among the tested cadaveric compounds, butan-1-ol and DMDS elicited the strongest EAG from both T. sinuatus male and female antennae. In a two-arm olfactometer, males and females were significantly attracted to dimethyldisulfide (DMDS) for both tested doses, whereas only males were attracted to p-cresol at 100 ng. Putrescine was repellent to males at the dose of 1 µg [less ▲]

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See detailThe community of Hymenoptera parasitizing necrophagous Diptera in an urban biotope
Frederickx, Christine ULg; Dekeirsschieter, Jessica ULg; Verheggen, François ULg et al

in Journal of Insect Science [=JIS] (2013), 13(32),

Most reports published in the field of forensic entomology are focused on Diptera and neglect the Hymenoptera community. However, Hymenoptera are part of the entomofaunal colonisation of a dead body. The ... [more ▼]

Most reports published in the field of forensic entomology are focused on Diptera and neglect the Hymenoptera community. However, Hymenoptera are part of the entomofaunal colonisation of a dead body. The use of Hymenoptera parasitoids in forensic entomology can be relevant to evaluate the time of death. Hymenoptera parasitoids of the larvae and pupae of flies may play an important role in the estimation of the post-mortem period, because their time of attack is often restricted to a small, well-defined windows of time in the development of the host insect. However, these parasitoids can interfere with the developmental times of colonising Diptera, and therefore a better understanding of their ecology is needed. The work reported here monitored the presence of adult Hymenoptera parasitoids on decaying pig carcasses in an urban biotope during the summer season (from May to September). Six families and six species were recorded in the field: Aspilota fuscicornis Haliday, Alysia manducator Panzer, Nasonia vitripennis Walker, Tachinaephagus zealandicus Ashmead, Trichopria sp., and Figites sp. In the laboratory, five species emerged from pupae collected in the field: Trichopria sp., Figites sp., A. manducator, N. vitripennis, and T. zealandicus. These five species colonise a broad spectrum of Diptera hosts, including those species associated with decomposing carcasses: Calliphoridae, Muscidae, Fanniidae, and Sarcophagidae [less ▲]

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See detailSubstrate Marking by an Invasive Ladybeetle: Seasonal Changes in Hydrocarbon Composition and Behavioral Responses
Durieux, Delphine ULg; Fassotte, Bérénice ULg; Vanderplanck et al

in PLoS ONE (2013), 8(4),

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during the winter to survive the cold. Recent published reports have highlighted that overwintering individuals ... [more ▼]

The multicolored Asian ladybeetle, Harmonia axyridis (Pallas), aggregates inside dwellings during the winter to survive the cold. Recent published reports have highlighted that overwintering individuals use hydrocarbon markings deposited on surfaces by conspecifics to orient toward aggregation sites. In the current study, monthly GC-MS analyses revealed seasonal modifications in the chemical profile of substrate markings deposited by moving individuals. The markings of overwintering ladybeetles contained larger proportions of heptacosadiene, nonacosadiene, hentriacontadienes, and methyl-nonacosanes, along with a lower proportion of heptacosene and nonacosene. This finding suggests the importance of the unsaturated and/or branched hydrocarbons in the H. axyridis aggregation process. Subsequently, we conducted behavioral assays to test whether (1) there is seasonal variation in the behavioral response of H. axyridis individuals toward substrate markings deposited by conspecifics in the same physiological state and (2) the observed behavioral modification is due to a change in ladybeetle sensitivity and/or a change in the chemical composition of the substrate marking. The results indicate that overwintering individuals exhibit a stronger ‘‘following’’ response toward conspecific substrate markings. This behavior is linked to both the physiological state of ladybeetles and the specific chemical profile of the marking biomolecules deposited under overwintering conditions. [less ▲]

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See detailLe langage olfactif des insectes: un atout pour la lutte biologique
Verheggen, François ULg

in Biofutur (2013), 341

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See detailConsumption of Immature Stages of Colorado Potato Beetle by Chrysoperla Carnea (Neuroptera: Chrysopidae) Larvae in the Laboratory
Sablon, Ludovic ULg; Haubruge, Eric ULg; Verheggen, François ULg

in American Journal of Potato Research (2013), 90(1), 51-57

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), has been an important defoliator of potatoes for 150 years. Although the use of insecticides allowed drastic reductions of CPB ... [more ▼]

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), has been an important defoliator of potatoes for 150 years. Although the use of insecticides allowed drastic reductions of CPB populations, resistance development against active substances has been observed. In this context, biological control using predatory larvae of the lacewing may represent a good alternative. CPB egg and larval consumption rates have been evaluated for all Chrysoperla carnea (Stephens) instars for 24 h. While first and second C. carnea instars only consumed eggs (1.3 and 1.8), first (1.5 and 2.4) and second (0.6 and 0.8) CPB instars, third instar of lacewing consumed all CPB immature stages: 6.8 CPB eggs, 8.5 first, 4 s, 0.5 third and 0.1 fourth CPB instars. This third instar killed 4-fold more CPB larvae than other larval stages. Handling time for third instar lacewing has been evaluated at 52 min on first instar CPB, 102 min on second instar and 164 min on third instar. Our laboratory assays highlight a potential for lacewing larvae to control CPB immature stages with a greater efficiency on young CPB larval stages. Fields assays are however needed to confirm efficiency of this CPB natural enemy under field conditions. [less ▲]

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See detailPropensity of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), to Develop on Four Potato Plant Varieties
Caparros Megido, Rudy ULg; Brostaux, Yves ULg; Haubruge, Eric ULg et al

in American Journal of Potato Research (2013), 90

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is now considered to be one of the most damaging invasive pests of tomatoes in the world. Tomato is regarded as the main host of T. absoluta ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is now considered to be one of the most damaging invasive pests of tomatoes in the world. Tomato is regarded as the main host of T. absoluta, but the pest can also feed, develop and reproduce on other cultivated Solanaceae, such as potato (Solanum tuberosum L). In the present study, we examined the ability of T. absoluta to develop on four commonly cultivated varieties of potato, under laboratory conditions. The survival rate of T. absoluta did not differ between the five tested host plants (tomato: Solanum lycopersicum cv. Moneymaker; and potato: Solanum tuberosum cv. Spunta, Charlotte, Nicola, and Bintje), but its development time (egg to pupation) was significantly affected. Compared to tomato, development times were longer on Bintje and shorter on Nicola, Charlotte, and Spunta. These results show the high capacity of T. absoluta to develop on potato crops. [less ▲]

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See detailWireworms’ Management: An Overview of the Existing Methods, with Particular Regards to Agriotes spp. (Coleoptera: Elateridae)
Barsics, Fanny ULg; Haubruge, Eric ULg; Verheggen, François ULg

in Insects (2013), 4(1), 117-152

Wireworms (Coleoptera: Elateridae) are important soil dwelling pests worldwide causing yield losses in many crops. The progressive restrictions in the matter of efficient synthetic chemicals for health ... [more ▼]

Wireworms (Coleoptera: Elateridae) are important soil dwelling pests worldwide causing yield losses in many crops. The progressive restrictions in the matter of efficient synthetic chemicals for health and environmental care brought out the need for alternative management techniques. This paper summarizes the main potential tools that have been studied up to now and that could be applied together in integrated pest management systems and suggests guidelines for future research. [less ▲]

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See detailForensic Entomology Investigations From Doctor Marcel Leclercq (1924-2008): A Review ofCases From lg69 to 2005
Dekeirsschieter, Jessica; Frederickx, Christine; Verheggen, François ULg et al

in Journal of Medical Entomology (2013), 50(5), 935-954

Doctor Marcel Leclercq was a pioneer in the field of forensic entomology. He has provided his knowledge of insect biology to many forensic cases, and most of them have found the way to publication. Most ... [more ▼]

Doctor Marcel Leclercq was a pioneer in the field of forensic entomology. He has provided his knowledge of insect biology to many forensic cases, and most of them have found the way to publication. Most of the papers he has written were focused on individual cases, and despite the abundance of entomoforensic investigations he conducted, no synthesis has been published. This paper summarizes 36 years of forensic entomological investigations in temperate Europe, mainly in Belgium. Leclercq’s work includes 132 entomological cases involving 141 human corpses found in various death scenes. Under certain conditions, insect specimens found on death scene can provide information on when (postmortem interval estimation), where and how a person died. More or less one hundred insect species associated to a dead body have been identified by Marcel Leclercq. [less ▲]

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See detailInfluence de la plante nourricière sur différents paramètres du développement larvaire du ver à soie, Borocera cajani : un cas d’étude sur plants de tapia et de voafotsy
Wilmet, Leslie ULg; Haubruge, Eric ULg; Verheggen, François ULg

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Many plant and animal species are endemic in Madagascar. Among them, the silk moth Borocera cajani, commonly named landibe, and which belongs to the Lasiocampidae family. It is a pholyphageous insect ... [more ▼]

Many plant and animal species are endemic in Madagascar. Among them, the silk moth Borocera cajani, commonly named landibe, and which belongs to the Lasiocampidae family. It is a pholyphageous insect, with five larval stages followed by a complete metamorphosis in the pupal stage to turn into an adult; a nocturnal butterfly. Landibe’s principal habitat is composed of an endemic plant species in Madagascar: tapia (Uapaca bojeri, Euphorbiaceae). For a long time, this ecosystem was disturbed and seriously threatened. Today, in the area of Arivonimamo, procedures to ensure its protection exist and the “Associations Communautaires de Base” (COBA) are in charge of their respect. Activities related to silk industry can consist in important incomes for many families in the area of Antananarivo, increasing their standard of living. This research aims at increasing our general knowledge on Borocera cajani and more especially on its larvae cycle. We studied the influence of two feeding plants; tapia and voafotsy (Aphloia theaeformis), on several parameters of larvae development cycle, and we compared wild and laboratory breeding. Preference tests have also been carried out in the laboratory. Results showed that feeding plants have influence on some of the parameters of the landibe’s cycle development. Wild and laboratory breeding comparison revealed an influence on animals’ size. Preference tests showed that larvae, which grow up on voafotsy, developed a preference for this feeding plant. Current publications and scientific knowledge on Borocera cajani are still too small. This study brings complementary and essential information on landibe, which should receive legal protection status in order to avoid its disappearance. [less ▲]

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See detailCharacterization of volatile organic compounds emitted by Barley (Hordeum vulgare L.) roots and their attractiveness to wireworms
Gfeller, Aurélie; Laloux, Morgan; Barsics, Fanny ULg et al

in Journal of Chemical Ecology (2013), 39(8), 1129-1139

Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here for the first time on the identification ... [more ▼]

Root volatile organic compounds (VOCs), their chemistry and ecological functions have garnered less attention than aboveground emitted plant VOCs. We report here for the first time on the identification of VOCs emitted by barley roots (Hordeum vulgare L.). Twenty nine VOCs were identified from isolated 21-d-old roots. The detection of root volatiles was dependent on the medium used for root cultivation. From 7-d-old roots cultivated on sterile Hoagland gelified medium, 24 VOCs were identified, on sterile vermiculite 33 VOCs, and on non-sterile vermiculite 34 VOCs. The major VOCs identified were fatty acid derived compounds, including hexanal, methyl hexanoate, (E)-hex-2-enal, 2-pentylfuran, pentan-1-ol, (Z)-2-(pentenyl)-furan, (Z)-pent-2-en-1-ol, hexan-1-ol, (Z)-hex-3-en-1-ol, (E)-hex-2-en-1-ol, oct-1-en-3-ol, 2-ethylhexan-1-ol (likely a contaminant), (E)-non-2-enal, octan-1-ol, (2E,6Z)-nona-2,6-dienal), methyl (E)-non-2-enoate, nonan-1-ol, (Z)-non-3-en-1-ol, (E)-non-2-en-1-ol, nona-3,6-dien-1-ol and nona-2,6-dien-1-ol. In an olfactometer assay, wireworms (larvae of Agriotes sordidus Illiger, Coleoptera: Elateridae) were attracted to chemical cues emanating from barley seedlings. We discuss the role of individual root volatiles or a blend of the root volatiles detected here and their interaction with CO2for wireworm attraction. [less ▲]

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See detailAnalyse des facteurs anthropiques de dégradation des bois de tapia (Uapaca bojeri) d'Arivonimamo
Rakotondrasoa, Olivia Lovanirina; Ayral, Astrid; Stein, Julien et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

The tapia woodland, an endemic ecosystem of Madagascar, plays an important role in the household economy of the local communities. The dependence of local people on the tapia woodland has led to the ... [more ▼]

The tapia woodland, an endemic ecosystem of Madagascar, plays an important role in the household economy of the local communities. The dependence of local people on the tapia woodland has led to the disturbance and degradation of this ecosystem. In this context, the current study aimed to identify and analyze the anthropogenic factors leading to the degradation of the tapia woodland in Arivonimamo. The working hypothesis was that fire constitutes today the main disturbance factor of the tapia woodland in Arivonimamo, leading to the deforestation and to a continuous degradation of this ecosystem. A typology of indicators of vegetation disturbance was established based upon literature; it was followed by an inventory of these indicators along four transects situated orthogonally around the six villages of the study site. This study showed that fire is no longer the main cause of deforestation and degradation of tapia woodlands in Arivonimamo. The continuing degradation of the woodland is mainly caused by illegal logging by the local population. These results provide key information to improve the management of the tapia woodlands in Arivonimamo. [less ▲]

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See detailActivité journalière et comportement d’alimentation de Borocera cajani Vinson 1863 (Lepidoptera: Lasiocampidae) sur deux de ses plantes hôtes : Uapaca bojeri Baillon 1874 et Aphloia theiformis (Vahl) Bennett 1840
Razafimanantsoa, Tsiresy; Raminosoa, Noromalala; Rakotondrasoa, Olivia et al

in Verheggen, François; Bogaert, Jan; Haubruge, Eric (Eds.) Les vers à soie malgaches : Enjeux écologiques et socio-économiques (2013)

Borocera cajani or landibe is a wild silk-moth, which silk is the most widely used in the textile industry in Madagascar. This endemic species is found throughout the island, but colonizes especially the ... [more ▼]

Borocera cajani or landibe is a wild silk-moth, which silk is the most widely used in the textile industry in Madagascar. This endemic species is found throughout the island, but colonizes especially the tapia forest in the central Highlands. The species has an important economic, culinary and cultural role in the Island. It is polyphagous and frequents several host plants. The daily activity of the larvae of B. cajani has been studied in their natural habitat on two native host plants of the tapia forest: Uapaca bojeri and Aphloia theiformis. Continuous observations during 24 hours on 54 individuals of the last instar of B. cajani have been conducted. Daily periods of activity were found to vary according to the host plant species. Larvae feeding on U. bojeri allocate 6.9% of their time to feed, while the larvae feeding on A. theiformis spend 3.3% of their time. Only 1.0% (15 minutes) and 0.7% (10 minutes) of the observed periods were allocated to movement, in the larvae feeding on U. bojeri et A. theiformis, respectively. Larvae observed on A. theiformis took an average of 3.1 ± 0.2 meals a day, which lasted 15,4 ± 1,3 min. Larvae observed on U. bojeri took an average of 1.9 ± 0.1 meals a day, which lasted 54.8 ± 5.2 min. [less ▲]

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