References of "Bragard, Claude"
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See detailTransmission Efficiency of Cucumber Mosaic Virus by Myzus persicae According to Virus Strain and Aphid Clone from China
Bosquée, Emilie ULg; Yin, Ronling; Bragard, Claude et al

in Asian Journal of Plant Pathology (2016)

Background: Cucumber mosaic virus (CMV) is one of the most important viruses infecting vegetables in the fields throughout the world. Transmission efficiency of CMV could depend on the variability of ... [more ▼]

Background: Cucumber mosaic virus (CMV) is one of the most important viruses infecting vegetables in the fields throughout the world. Transmission efficiency of CMV could depend on the variability of virus strain but also aphid vector species and/or clones. Materials and Methods: By sequence analysis, the coat protein gene of CMV strains from different regions revealed that the CMV isolates used for this study belong to the same group. Both CMV strains and Myzus persicae (Sulzer) aphid clones were investigated for their role in viral dispersion by reciprocal tests on Nicotiana tabacum (L.) using the same clone of Myzus persicae towards different CMV strains or using one CMV strain on different Myzus persicae clones. Results: Virus transmission efficiency was found to be significantly influenced by selected CMV strains (from 5-30% of transmission rate for identical aphid clone) and also by the selected aphid clones (variation from 15-70% of transmission rate for identical virus strain). Conclusion: The CMV transmission efficiency depends on the variability of virus strain but also aphid vector clones. Combining the variability of CMV transmission rates for both aphid and virus sides, the prediction and modeling of virus spreading seems to be difficult to organize and are closely dependent on the variability of each protagonist-aphid and virus. [less ▲]

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See detailSURVEYS OF APHIDS AND POTATO VIRUS Y IN POTATO FIELDS IN WALLONIA, BELGIUM: A FOUR YEAR OVERVIEW
Bosquée, Emilie ULg; Yattara, Almouner A.; Crutzen, François et al

in Journal of Plant Pathology [=JPP] (2016)

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified ... [more ▼]

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified using yellow pan traps. Four thousands potato leaf samples collected in 87 plots from 29 fields were analysed for the presence and typing of PVY strains by RT-PCR. PVY was detected in 26%, 20% and 60% of the seed plots tested from 2009 to 2011, respectively. A higher prevalence of PVY was observed in plots of stock potatoes (60% in 2010 and 67% in 2011). The N/NTN strain of PVY was predominant, representing 70-99% of the strains. [less ▲]

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See detailBiological control of aphids in wheat and vegetable crops : a multi-approach case study in Shandong province (China)
Chevalier Mendes Lopes, Thomas ULg; Bosquée, Emilie ULg; Chen, Julian et al

Poster (2014, April 02)

This multi-approach study was conducted in the Shandong province (China) to assess the effectiveness of different biological control methods against aphids in wheat and vegetable crops. Three approaches ... [more ▼]

This multi-approach study was conducted in the Shandong province (China) to assess the effectiveness of different biological control methods against aphids in wheat and vegetable crops. Three approaches were tested: (1) wheat/oilseed rape and wheat/pea associations, (2) potatoes/peas association, and (3) E-β-farnesene (aphid alarm pheromone) releasers in squashes under plastic tunnels. Aphids and aphidophagous beneficials were monitored by observations on plants. Wheat associations and E-β-farnesene reduced aphid infestations compared with control treatments, while no effect was observed in the potatoes/peas association. Moreover, aphidophagous beneficials were significantly more abundant in the three kinds of associations compared with control treatments. Few individuals were observed on squashes. Additionally, adult aphidophagous beneficials were monitored using yellow pan traps. The parasitoid species Aphidius gifuensis (Ashmead) was prevalent, while Propylea japonica (Thunberg) and Harmonia axyridis (Pallas) were the most abundant species among predators. Globally, wheat associations were more efficient to reduce aphid infestations and attract aphidophagous beneficials to promote biological control. The trapping of natural enemies allowed to assess the diversity and abundance of aphidophagous species in this region. This study shows a beneficial effect of crop associations and E-β-farnesene on the control of aphid populations and contributes to assess the potentialities of these alternative methods to the use of insecticides. [less ▲]

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See detailEffect of wheat plant volatiles on aphids and associated predator behavior: selection of efficient infochemicals for field study
XIE, Hai-Cui; Durieux, Delphine ULg; fan, Jia et al

in Chinese Journal of Applied Entomology (2014), 51(6), 1470-1478

Semiochemicals are involved in tritrophic interactions and affect the behaviors of both herbivores and beneficial insects. Many volatile molecules from the wheat plant [Triticum aestivum L. (Gramineae ... [more ▼]

Semiochemicals are involved in tritrophic interactions and affect the behaviors of both herbivores and beneficial insects. Many volatile molecules from the wheat plant [Triticum aestivum L. (Gramineae)] have previously been identified. To understand their effects on aphids and related auxiliaries. [Methods] The impact of four of these volatiles; methyl-salycilate, cis-3-hexenyl acetate, hexenol, and 1-hexanol, was tested on the wheat aphid [Sitobion avenae (Fabricus) (Homoptera: Aphididae)] and two major predators of this pest encountered in field crops, the hoverfly (Episyrphus balteatus (DeGeer) (Diptera: Syrphidae)] and the multicoloured Asian ladybird [Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae)]. Different doses of these chemicals were tested by performing four arm-olfactometer and wind-tunnel assays. [Results] The results show that methyl-salycilate seemed to be attractive only toward H. axyridis but 3-hexenyl acetate and hexenol were attractive to both S. avenae and H. axyridis. However, these positive responses decreased with increased dose of the tested compounds. 3-hexenyl acetate also induced positive response in E. balteatus but 1-hexanol was more attractive to aphids than to their natural enemies. [Conclusion] In conclusion, these results highlight the potential benefit of combining methyl-salycilate, 3-hexenyl acetate and hexenol in push and pull traps aimed to control S. avenae. Contrary to the three aforementioned compounds, 1-hexanol did not seem to have much potential as a semiochemical for the biological control of aphids. Key words wheat, volatiles, infochemicals, aphid, predator, behaviour [less ▲]

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See detailMeasuring the general phytosanitary situation: development of a plant health barometer
Wilmart, Olivier; Van Huffel, Xavier; Diricks, Herman et al

in European Journal of Plant Pathology (2014), Online First Articles

The development of a plant health barometer, an instrument to measure the general phytosanitary situation on a national level (Belgium) and on a yearly basis and to monitor its evolution over time, is ... [more ▼]

The development of a plant health barometer, an instrument to measure the general phytosanitary situation on a national level (Belgium) and on a yearly basis and to monitor its evolution over time, is described. The elaboration of a set of 13 plant health indicators (PHI’s) as the basis for the plant health barometer is discussed. These indicators were weighted by experts - including scientists, policy makers and agroindustrial representatives - to determine their relative impact in the barometer. The result of the barometer is expressed as a comparison with the previous year. Based on the results of the 13 PHI’s, it is concluded that the general plant health in Belgium shows a positive evolution from 2007 until 2010 and a negative evolution from 2010 until 2012. The plant health barometer provides a overview of the phytosanitary situation of plants and plant products in Belgium and is a tool to communicate in an intelligible, comprehensible manner on aspects of plant health to consumers and professional stakeholders in the plant production chain. Together with the food safety barometer and the animal health barometer, the plant health barometer is one of the three instruments to provide a overview on the general status of the safety of the food chain in Belgium. [less ▲]

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See detailEvaluation de la diversité de l’entomofaune en cultures maraîchères dans l’est de la Chine
Polo Lozano, Damien ULg; Bosquée, Emilie ULg; Chevalier Mendes Lopes, Thomas ULg et al

in Entomologie Faunistique = Faunistic Entomology (2013), 66

Within the framework of research aimed at developing biological control in vegetable crops in Shandong province in China, a pest and associated auxiliary entomophagous insects monitoring was conducted to ... [more ▼]

Within the framework of research aimed at developing biological control in vegetable crops in Shandong province in China, a pest and associated auxiliary entomophagous insects monitoring was conducted to determine entomological groups of agricultural interest and compare them to the situation in Belgium. The diversity and abundance of the entomofauna were assessed in potato and zucchini fields between May 9th and June 13th, 2011, using yellow traps and in situ observations on host plants. A total of 36 466 and 34 806 insects were trapped or observed on the plants in zucchini and potato fields, respectively. Ten orders and more than sixty families in each crop were identified. Aphids widely predominated in the traps and exerted a strong pressure on both crops early in the season. Other families of pests have been identified but no specific pest of these two crops and the investigated region is among the collections. [less ▲]

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See detailInfluence of Garlic Intercropping or Active Emitted Volatiles in Releasers on Aphid and Related Beneficial in Wheat Fields in China
Haibo, Zhou; Chen, Julian; Yong, Liu et al

in Journal of Integrative Agriculture (2013), 12(3)

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See detailEvaluation de la diversité des pucerons et de leurs ennemis naturels en cultures maraîchères dans l’est de la Chine
Chevalier Mendes Lopes, Thomas ULg; Bosquée, Emilie ULg; Polo Lozano, Damien ULg et al

in Entomologie Faunistique = Faunistic Entomology (2012), 64(3), 63-71

The aim of this study was to evaluate the diversity and abundance of aphids and aphidophagous beneficials in courgettes and potato fields in the Shandong province, East of China. The assessment of aphid ... [more ▼]

The aim of this study was to evaluate the diversity and abundance of aphids and aphidophagous beneficials in courgettes and potato fields in the Shandong province, East of China. The assessment of aphid and related beneficial populations was conducted between May 9th and June 13th, 2011, using yellow traps and in situ observations on plants. A total of 53,206 insects were trapped and 35,144 observed on the plants. Aphids widely predominated in the traps and exerted a strong pressure on both crops early in the season. Two main species were identified on the plants, namely Aphis gossypii on the courgettes and Myzus persicae on the potatoes. Ladybirds were the most abundant aphidophagous predators, especially Coccinella septempunctata on the courgettes and Propylea japonica on the potato fields, the first one being earlier than the second. Only few hoverflies and lacewings were captured. Microhymenoptera appeared later in the season. The Aphidius gifuensis species represented the majority of trapped Braconidae, while the family Aphelinidae contained the largest number of individuals in the aphidiphagous. [less ▲]

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See detailE-b-farnesene synergizes the influence of an insecticide to improve control of cabbage aphids in China
Cui, L.L; Dong, J.; Francis, Frédéric ULg et al

in Crop Protection (2012)

Extensive use of pesticides to control insect pests can have negative effects on the environment, natural enemies and food safety. The aphid alarm pheromone, E-b-farnesene (Ebf), appears to hold strong ... [more ▼]

Extensive use of pesticides to control insect pests can have negative effects on the environment, natural enemies and food safety. The aphid alarm pheromone, E-b-farnesene (Ebf), appears to hold strong potential for controlling a wide variety of aphid pests. To understand the control potential of Ebf, we used field experiments in a factorial design to test its influence and that of the insecticide imidacloprid on populations of aphids Lipaphis erysimi (Kaltenbach) and Myzus persicae (Sulzer) on Chinese cabbage, Brassica rapa pekinensis (Brassicales: Brassicaceae). Our results showed imidacloprid treatment alone can significantly decrease aphid populations, and that combining insecticide with Ebf further reduced numbers of apterous aphids at distances of 5 m from pheromone emitters in two years of our experiments. Our results demonstrate that imidacloprid can be effective in reducing the abundance of aphids in Chinese cabbage fields, but the degree of control can be even stronger in the presence of Ebf. [less ▲]

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See detailExposure of several Belgian consumer groups to pesticide residues through fresh fruit and vegetable consumption
Claeys, Wendie L.; Schmit, Jean-François; Bragard, Claude et al

in Food Control (2011), 22(3-4), 508-516

The output of a pesticide surveillance program (detection frequency and number of exceeding measures) can lead to unnecessary concern among consumers since they lack information concerning the actual ... [more ▼]

The output of a pesticide surveillance program (detection frequency and number of exceeding measures) can lead to unnecessary concern among consumers since they lack information concerning the actual exposure. In this study, the exposure to pesticide residues through fruit and vegetable consumption is evaluated based on the 2008 surveillance data of the Belgian Federal Agency for the Safety of the Food Chain (FASFC). Results (deterministic and probabilistic approach) demonstrate that the chronic exposure of the adult population (>15 years) is generally under control, even at high or frequent consumption of fruit and vegetables. For most of the pesticide residues studied, the exposure is one hundred times lower than the ‘acceptable daily intake’ or ADI. With regard to children (2e5 years) who consume regularly or large amounts of fruit and vegetables, there are however, indications that for some pesticides the ADI can be exceeded. Nevertheless, due to the large uncertainty in these calculations, a more detailed study is required for this vulnerable group of consumers. In addition, it was demonstrated that washing and peeling of fruit and vegetables result in an exposure that is probably five to six times lower. [less ▲]

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See detailFarming systems in the sandy area of the Thua Thien Hue Province, Central Vietnam, survey of socio-economic situation and constraints identified by farmers
Pham Khanh, Tu; Hoang Thi Thai, Hoa; Hoang Nghia, Duyet et al

in Improving food crop productivity in the coastal sandy area of the Thua Thien Hue Province Central Vietnam : Vietnam-Belgium interuniversity project 2004-2009 (2009)

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