References of "Gaspar, Charles"
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See detailTechnique de lombriculture au Sud Vietnam
Francis, Frédéric ULg; Haubruge, Eric ULg; Pham Tat Thang et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2003), 7(3-4), 171-175

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See detailAphid prey suitability as environmental effect on Adalia bipunctata reproduction.
Vanhaelen, Nicolas; Gaspar, Charles ULg; Francis, Frédéric ULg

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (2002), 67(3), 563-8

Secondary plant metabolites (allelochemicals) play a major role in plant-insect interactions. Glucosinolates (GLS) and their degradation products from Brassica species are attractants and feeding ... [more ▼]

Secondary plant metabolites (allelochemicals) play a major role in plant-insect interactions. Glucosinolates (GLS) and their degradation products from Brassica species are attractants and feeding stimulants for Brassicaceae specialist insects but are generally repellent and toxic for generalist herbivores. The impact of these compounds on crucifer specialist insects are well known but their effect on generalist predators is still not well documented. Prey host plant influence on reproduction of an aphidophagous beneficial, the two spot ladybird, was determined using the cabbage aphid, Brevicoryne brassicae reared on a crucifer plant, namely Brassica napus containing low GLS levels. As ladybird developmental and reproductive parameters were already shown to be strongly affected by the allelochemical presence in its preys, the unsuitable aphid and host plant combination was only momentary used to feed the A. bipunctata adults. A strong impact of the diet was observed on the beetle fecundity and the emerging offspring. Changing B. brassicae aphid to a suitable prey slowly improved the temporary negative effect of the former diet. These results enhance the food environmental effect and the importance of tritrophic relations in pest management strategies by predators. Indeed, more than the choice of the beneficial species, the prey host plant has a major influence on the potential efficacy of biological agent to control herbivore species such as aphids. [less ▲]

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See detailImpact of close habitat on the entomological diversity and abundance in carrot open fields.
Colignon, P.; Gaspar, Charles ULg; Haubruge, Eric ULg et al

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (2002), 67(3), 481-6

Vegetable open fields areas have been increasing for the last decade in Wallonia (South part of Belgium), mainly in Hesbaye. To be in accordance with quality standards, especially in terms of agrochemical ... [more ▼]

Vegetable open fields areas have been increasing for the last decade in Wallonia (South part of Belgium), mainly in Hesbaye. To be in accordance with quality standards, especially in terms of agrochemical residues (R.M.L.), biological pest control was developed and reduces the insecticide use, leading to have safer fresh products. Carrot represents an important cultivated species in Wallonia. To asses the impact of close habitat on both pest (mainly aphids) and beneficial insects, carrot fields were investigated during all the production duration in 2000. Twelve fields between Waremme and Hannut were visited weekly from June to October. Insects were caught using yellow traps and determined to the family level. Approximately 90,000 insects belonging to 109 families were identified. Significant differences linked to field closed habitat were observed on 31 families. An increase of biodiversity in term of family number near set-asides and woody borders was observed. Evaluation of pest and beneficial diversity and density in vegetable crops was discussed to promote future IPM program. [less ▲]

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See detailIncreased fecundity of malathion-specific resistant beetles in absence of insecticide pressure
Arnaud, Ludovic; Brostaux, Yves ULg; Assie, Lazare Komenan et al

in Heredity (2002), 89(6), 425-429

Despite that resistance frequency is assumed to decline when selective pressure is relaxed, the stability of resistance frequency has been observed in some insects in the absence of insecticide. In the ... [more ▼]

Despite that resistance frequency is assumed to decline when selective pressure is relaxed, the stability of resistance frequency has been observed in some insects in the absence of insecticide. In the red flour beetle, Tribolium castaneum, the first case of malathion-resistance was reported in the early 1960s. The malathion-specific resistant phenotype has now almost completely replaced the susceptible one in red flour beetle populations. In the present study, several life-history traits that could influence the fitness of the insects were compared between insecticide-susceptible and malathion-specific resistant populations of the red flour beetle. On average, egg fertility and egg-to-adult development time did not differ between susceptible and resistant populations. However, the fecundity of resistant females was greater than that of susceptible ones. Generally, differences in development time between insecticide resistant and susceptible populations are considered as having more effect on fitness than do differences in fecundity. However, the observed increased female fecundity may participate, in combination with the previously observed increased male reproductive success, to the development and the stability of malathion-specific resistance in T. castaneum. [less ▲]

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See detailEffects of insecticide treatments on insect density and diversity in vegetable open fields.
Colignon, P.; Hastir, Pierre; Gaspar, Charles ULg et al

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (2001), 66(2a), 403-411

Vegetable open field areas increased for 15 years in Wallonia, mainly in Hesbaye. To be in accordance with quality standards, especially in terms of agro-chimical residues (R.M.L.), biological pest ... [more ▼]

Vegetable open field areas increased for 15 years in Wallonia, mainly in Hesbaye. To be in accordance with quality standards, especially in terms of agro-chimical residues (R.M.L.), biological pest control was developed and allowed to reduce the insecticide use, leading to have safer fresh products. Among cultivated species in Wallonia, leguminous crops represent more than 85% of the vegetable production. To assess the impact of insecticide treatment on both pests (mainly aphids) and beneficial insects (predators and parasitoids), broad bean (Vicia faba L.) fields were investigated during all the production duration. Twelve fields between Waremme and Hannut were visited weakly from May to July. In each field, control untreated and treated plots were investigated. Insects were caught using yellow traps and determined until the family level. Approximately 90.000 insects belonging to 59 major families (99% of captures) and 64 minor families were identified. These results showed that biodiversity in terms of family numbers was significantly higher in unsprayed plots. In addition, biodiversity and biomass (insect density) increased gradually during the season. Evaluation of pest and beneficial diversity and density was discussed in relation to aphicid (lambda-cyhalothrin, pirimicarb) treatments and the development of I.P.M. program in vegetable crops. [less ▲]

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See detailOviposition preferences of Episyrphus balteatus.
Vanhaelen, Nicolas; Haubruge, Eric ULg; Gaspar, Charles ULg et al

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (2001), 66(2a), 269-75

A crucial aspect of predator oviposition behaviour is host plant choice, especially in hoverflies where the newly hatched offspring are unable to move a great distance to search for the appropriate prey ... [more ▼]

A crucial aspect of predator oviposition behaviour is host plant choice, especially in hoverflies where the newly hatched offspring are unable to move a great distance to search for the appropriate prey. Such offspring must generally feed on the host plant aphids previously selected by the mother. Some factors involved in the selection of the oviposition site of Episyrphus balteatus De Geer include aphids associated to chemical stimuli, aphid colony size and host plant characteristics. Here we tested the hypothesis that there will not only be a rank order hierarchy of preference for aphid prey species reared on the same host plant but that a similar hierarchy of different host plant of one aphid species could be established. Therefore we compared the number of eggs laid on different combinations of host plant and aphid species. Vicia faba L., secondary metabolites free, Brassica napus L. and Sinapis alba L., containing low and high levels of glucosinolates respectively were used. The latter compounds are well known allelochemicals from Brassicaceae having a strong influence on specialist and generalist insects from both phytophagous and entomophagous levels. These experiments enhance the importance of tritrophic interactions in biological control of pests by underlining the host plant influence on aphidophagous predators, either directly or through the odours emitted by the phytophagous prey. [less ▲]

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See detailEvolution of aphidophagous ladybird populations in a vegetable crop and implications as biological agents.
Francis, Frédéric ULg; Colignon, P.; Hastir, P. et al

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (2001), 66(2a), 333-40

Aphidophagous predators such as hoverfly and ladybird beetles are effective biological agents to control aphid pests in perennial and annual cultivated species. Introduction and conservation of beneficial ... [more ▼]

Aphidophagous predators such as hoverfly and ladybird beetles are effective biological agents to control aphid pests in perennial and annual cultivated species. Introduction and conservation of beneficial insects are two ways to increase natural control of pests. Whether massive releases of entomophagous insects are expensive and time consuming, the preservation of predator natural populations can be expected by reducing and by adapting chemical treatments in crop fields. Vegetable cultivated areas increased in Belgium for several years, mainly Fabaceae species such as peas and beans. In this work, the evolution of ladybird species population was assessed from May to June in broad bean fields (Vicia faba L.) between Waremme and Hannut, in Hesbaye. Weekly, the aphid and aphidophagous beetle populations were collected from yellow traps and determined on plants by visual observations. Even if five ladybird species were identified, three of them represented more than 95% of the collected insects (Coccinella septempunctata L., Propylea quatuor-decimpunctata L. and Psyllobora vingintiduopunctata L.). Evolution of coccinellid populations during the cultivation season was discussed in relation to the presence of potential aphid preys and the agrochemical treatments which were applied. Integrated pest management in vegetable fields constitute a reliable way to increase the quality level of fresh vegetables in terms of pesticide residue limitations. [less ▲]

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See detailGlutathione S-transferases of Aulacorthum solani and Acyrthosiphon pisum: partial purification and characterization.
Francis, Frédéric ULg; Haubruge, Eric ULg; Gaspar, Charles ULg et al

in Comparative Biochemistry & Physiology Part B (2001), 129(1), 165-71

Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile ... [more ▼]

Glutathione S-transferases (GST) play an important role in the detoxification of many substances including allelochemicals from plants. Brassicaceae plants contain glucosinolates and emit volatile isothiocyanates which affect the GST system. A comparison of the GST of two aphid species, the generalist Aulacorthum solani found on Brassicaceae and the Fabaceae specialist Acyrthosiphon pisum, was made to try to explain their respective feeding behaviour. Differences of GST were determined among the two aphid species based on purification by affinity chromatography, SDS-PAGE and on kinetic studies. Purification yields using an epoxy-activated Sepharose 6B column were highly different for the two aphid species (18% and 34% for A. solani and A. pisum, respectively). These variations were confirmed by SDS-PAGE. While only a 27-kDa band was observed for A. pisum, two bands of approximately 25-kDa were visualized for the generalist aphid, A. solani. Considering the kinetic results, differences of Km and Vmax were observed following the aphid species when a range of substrates (CDNB and DCNB) and GSH concentrations were tested. Studies on the detoxification enzymes of generalist and specialist herbivores would be undertaken to determine accurately the effect of the host plant on the organisms eating them, particularly in terms of biochemical and ecological advantages. [less ▲]

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See detailAphid host plant and food suitability for aphidophagous larvae: impact on ladybird reproductive performance.
Francis, Frédéric ULg; Haubruge, Eric ULg; Gaspar, Charles ULg

in The BCPC Conference: Pests and diseases, Volume 3. Proceedings of aninternational conference held at the Brighton Hilton Metropole Hotel,Brighton, UK, 13-16 November 2000 (2000)

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See detailMise en evidence de la tolerance de Tribolium castaneum a l'egard d'une formulation a base de terre de diatomees.
Haubruge, Eric ULg; Rigaux, M.; Arnaud, L. et al

in Bulletin OILB/SROP = IOBC/WPRS Bulletin (2000), 23(10),

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See detailMalathion Resistance Increases Male Reproductive Success In Tribolium Castaneum (Coleoptera : Tenebrionidae)
Arnaud, L.; Haubruge, Eric ULg; Gaspar, Charles ULg

in Annales de la Societe Entomologique de France (1999), 35

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See detailEffect of ice-nucleating bacteria (Pseudomonas syringae Van Hall) on insect susceptibility to sub-zero temperatures
Mignon, Jacques ULg; Haubruge, Eric ULg; Gaspar, Charles ULg

in Journal of Stored Products Research (1998), 34(1), 81-86

Many stored product insect pests are termed "freeze-intolerant" because they cannot survive ice formation in their extracellular body fluid. In grain silos, the progressive decrease in temperature permits ... [more ▼]

Many stored product insect pests are termed "freeze-intolerant" because they cannot survive ice formation in their extracellular body fluid. In grain silos, the progressive decrease in temperature permits the acclimation of insects and enhances their cold tolerance. The objective of this study was to examine the influence of the concentration of the ice-nucleating-active bacterium Pseudomonas syringae (10, 100 and 1000 ppm), temperature and duration of sub-zero exposure on the cold tolerance of the granary weevil Sitophilus granarius (L.) and the saw-toothed grain beetle Oryzaephilus surinamensis (L.). After an application of 1000 ppm of powdered P. syringae to grain, the mortality of S. granarius and O. surinamensis was increased after 24-h exposure to -4 degrees C. Higher mortality was observed after exposure to colder temperatures and a dose-response relationship was evident. At near-zero (-4 to 0 degrees C) negative temperatures, no dose response was observed, and the mortality in treated grain was the same as that in untreated grain. (C) 1998 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailMortality in Oryzaephilus surinamensis following short-term exposure to conditioned kernels by high-density culture
Mignon, Jacques ULg; Haubruge, Eric ULg; Lienard, Valérie et al

in Entomologia Experimentalis et Applicata (1996), 80(3), 555-557

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See detailInfluence of thermal acclimation on the survival of Sitophilus granarius (L) and Oryzaephilus surinamensis (L) at low temperatures
Mignon, Jacques ULg; Haubruge, Eric ULg; Gaspar, Charles ULg

in Netherlands Journal of Zoology (1996), 46(3-4), 317-325

Low temperatures have been used for many years to control populations of stored-product insects. The aim of aeration was primarily to cool down the grain and then to prevent its deterioration by reducing ... [more ▼]

Low temperatures have been used for many years to control populations of stored-product insects. The aim of aeration was primarily to cool down the grain and then to prevent its deterioration by reducing the number of insects. In Belgium, the mild winters enable insects to survive to the next season. In autumn, the progressive lowering of temperature has an acclimation effect on stored-product insects. The present study was undertaken to determine the survival at low temperatures of non cold-acclimated and laboratory- and field-cold-acclimated insects. We have chosen to work with the granary weevil Sitophilus granarius (L.) and the saw-toothed grain beetle Oryzaephilus surinamensis (L.). They are the most frequent stored-grain pests in Belgium. To compare the cold-hardiness of different laboratory cold-acclimated insects, S. granarius and O. surinamensis were placed at nine different cold-acclimation temperature regimes. Insects were kept at 5 degrees C for 2, 4 and 6 weeks or at -5 degrees C for 4, 7 and 14 days. To assess the field-cold-acclimation in autumn and in winter, insects were monthly taken from a bin and transferred to 5 degrees C for 6 weeks. S. granarius adults were more cold-hardy than O. surinamensis, but O. surinamensis adults compensated their cold-sensibility by a great ability to acclimate. S. granarius is able to survive the winter in Belgium because of its cold-hardiness while O. surinamensis survives because of its ability to acclimate to low temperatures. [less ▲]

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See detailComposition of the essential oil of Piper acutifolium Ruiz. and Pav. from Peru.
Lognay, Georges ULg; Bouxin, P.; Marlier, M. et al

in Journal of Essential Oil Research (1996), 8(6),

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See detailUtilisation de Bacillus subtilis (Cohn) comme insecticide a l'egard de Drosophila melanogaster (Meigen).
Lazare, K.; Haubruge, Eric ULg; Lienard, V. et al

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (1996), 61(3a),

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See detailThe use of low temperatures and ice-nucleating bacteria against stored product insects pests
Mignon, Jacques ULg; Haubruge, Eric ULg; Gaspar, Charles ULg

in Mededelingen van de Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen (Rijksuniversiteit te Gent) (1995), 60(3b), 977-984

The present study was undertaken to determine de survival at low temperature of non-cold-acclimated and cold-acclimated insects, and to evaluate the potential of using the ice-nucleating-active bacteria ... [more ▼]

The present study was undertaken to determine de survival at low temperature of non-cold-acclimated and cold-acclimated insects, and to evaluate the potential of using the ice-nucleating-active bacteria Pseudomonas syringae to increase susceptibility of stored-product insects (Sitophilus granarius and Oryzaephilus surinamensis) to cold treatments. [less ▲]

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