44 results on '"Gardès, L."'
Search Results
2. A moving window approach for nonparametric estimation of the conditional tail index
- Author
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Gardes, L. and Girard, S.
- Subjects
Mathematics - Statistics Theory ,Statistics - Methodology - Abstract
We present a nonparametric family of estimators for the tail index of a Pareto-type distribution when covariate information is available. Our estimators are based on a weighted sum of the log-spacings between some selected observations. This selection is achieved through a moving window approach on the covariate domain and a random threshold on the variable of interest. Asymptotic normality is proved under mild regularity conditions and illustrated for some weight functions. Finite sample performances are presented on a real data study.
- Published
- 2011
3. Functional nonparametric estimation of conditional extreme quantiles
- Author
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Gardes, L., Girard, S., and Lekina, A.
- Subjects
Mathematics - Statistics Theory ,Statistics - Methodology - Abstract
We address the estimation of quantiles from heavy-tailed distributions when functional covariate information is available and in the case where the order of the quantile converges to one as the sample size increases. Such "extreme" quantiles can be located in the range of the data or near and even beyond the boundary of the sample, depending on the convergence rate of their order to one. Nonparametric estimators of these functional extreme quantiles are introduced, their asymptotic distributions are established and their finite sample behavior is investigated.
- Published
- 2011
4. Bias-reduced estimators of the Weibull tail-coefficient
- Author
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Diebolt, J., Gardes, L., Girard, S., and Guillou, A.
- Subjects
Mathematics - Statistics Theory - Abstract
In this paper, we consider the problem of the estimation of a Weibull tail-coefficient. In particular, we propose a regression model, from which we derive a bias-reduced estimator. This estimator is based on a least-squares approach. The asymptotic normality of this estimator is also established. A small simulation study is provided in order to prove its efficiency.
- Published
- 2011
5. Gaussian Regularized Sliced Inverse Regression
- Author
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Bernard-Michel, C., Gardes, L., and Girard, S.
- Subjects
Mathematics - Statistics Theory - Abstract
Sliced Inverse Regression (SIR) is an effective method for dimension reduction in high-dimensional regression problems. The original method, however, requires the inversion of the predictors covariance matrix. In case of collinearity between these predictors or small sample sizes compared to the dimension, the inversion is not possible and a regularization technique has to be used. Our approach is based on a Fisher Lecture given by R.D. Cook where it is shown that SIR axes can be interpreted as solutions of an inverse regression problem. In this paper, a Gaussian prior distribution is introduced on the unknown parameters of the inverse regression problem in order to regularize their estimation. We show that some existing SIR regularizations can enter our framework, which permits a global understanding of these methods. Three new priors are proposed leading to new regularizations of the SIR method. A comparison on simulated data is provided., Comment: 26 pages, 16 figures
- Published
- 2011
6. Schmallenberg virus in Culicoides Latreille (Diptera: Ceratopogonidae) populations in France during 2011‐2012 outbreak
- Author
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Ségard, A., Gardès, L., Jacquier, E., Grillet, C., Mathieu, B., Rakotoarivony, I., Setier‐Rio, M.‐L., Chavernac, D., Cêtre‐Sossah, C., Balenghien, T., and Garros, C.
- Published
- 2018
- Full Text
- View/download PDF
7. First record of Stegomyia albopicta (= Aedes albopictus) in Morocco: a major threat to public health in North Africa?
- Author
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BENNOUNA, A., BALENGHIEN, T., EL RHAFFOULI, H., SCHAFFNER, F., GARROS, C., GARDÈS, L., LHOR, Y., HAMMOUMI, S., CHLYEH, G., and FASSI FIHRI, O.
- Published
- 2017
- Full Text
- View/download PDF
8. Foundation characteristics of edible Musa triploids revealed from allelic distribution of SSR markers
- Author
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Hippolyte, I., Jenny, C., Gardes, L., Bakry, F., Rivallan, R., Pomies, V., Cubry, P., Tomekpe, K., Risterucci, A. M., Roux, N., Rouard, M., Arnaud, E., Kolesnikova-Allen, M., and Perrier, X.
- Published
- 2012
9. Estimating the conditional tail index by integrating a kernel conditional quantile estimator
- Author
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Gardes, L., Guillou, A., and Schorgen, A.
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- 2012
- Full Text
- View/download PDF
10. A Note on Sliced Inverse Regression with Regularizations
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Bernard-Michel, C., Gardes, L., Girard, S., Li, Lexin, and Yin, Xiangrong
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- 2008
- Full Text
- View/download PDF
11. Molecular Typing and History of the Provins Roses Horticultural Group
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Gardes, L., Heizmann, P., and Joyaux, F.
- Published
- 2005
12. Repellent effect of topical deltamethrin on blood feeding by Culicoides on horses
- Author
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Robin, M., Archer, D., McGowan, C., Garros, C., Gardès, L., and Baylis, M.
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- 2015
- Full Text
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13. Composição bromatológica de silagens de milho comerciais produzidas no Brasil
- Author
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Faria, T.F.R., Pinese, F., Gimenes, F.M.A., Demarchi, J.A.A.A., Campos, F.P., Premazzi, L.M., Mattos, W.T., Gardès, L., Faria, T.F.R., Pinese, F., Gimenes, F.M.A., Demarchi, J.A.A.A., Campos, F.P., Premazzi, L.M., Mattos, W.T., and Gardès, L.
- Abstract
The objective was to perform the exploratory analysis of the chemical composition results and the use of models to estimate the total digestible nutrients of the corn silage samples generated from 12 years of commercial analyzes of the Animal Nutrition Laboratory of the Instituto de Zootecnia (IZ), in Nova Odessa, SP, Brazil. As a criterion, samples of corn silage had no additives, 220 samples in the periods from 2004 to 2015 were grouped in four triennia. These were characterized by their chemical composition through descriptive statistical analysis, Pearson correlations and the use of TDN estimation models, using four models of equations: one from Clemson University, one according Harlan and two according Kearl (1 and 2). The nutritional value of corn silage samples was of medium quality, with NDF values (49.2 to 57.2% of MS) above the ideal. All the equations could be used to estimate the NDT (variation of 54.3 to 67.0% in the triennia), Kearl 1 and Clemson showed the highest and the lowest variation between the triennia, respectively. The increase in nutrient value and TDN in triennial 3 and 4 indicates improvement in silage quality, Objetivou-se realizar a análise exploratória dos resultados bromatológicos e uso de modelos para estimativa de nutrientes digestíveis totais de amostras de silagens de milho, por meio dos dados gerados a partir de 12 anos de análises comerciais do Laboratório de Nutrição Animal do Instituto de Zootecnia (IZ), em Nova Odessa, SP, Brasil. Como critério, utilizaram-se dados de amostras de silagens de milho sem nenhum tipo de aditivos, somando 220 amostras nos períodos de 2004 a 2015 e agrupados em quatro triênios. Estes foram caracterizados quanto à sua composição bromatológica através de análise estatística descritiva, correlações de Pearson e pela utilização de modelos de estimativas de NDT, utilizando-se quatro modelos de equações: uma da Universidade de Clemson, uma segundo Harlan e duas segundo Kearl (1 e 2). O valor nutricional das amostras de silagens de milho mostrou-se de qualidade mediana, com valores de FDN (49,2 a 57,2% da MS) acima do ideal de 37 a 45% da MS. Todas as equações puderam ser utilizadas na estimativa do NDT (variação de 54,3 a 67,0% nos triênios) sendo que a de Kearl 1 e Clemson apresentaram a maior e a menor variação entre os triênios, respectivamente. O aumento do valor nutritivo e de NDT nos triênios 3 e 4 indica melhoria na qualidade da silagem.
- Published
- 2021
14. The threat of midge-borne equine disease: investigation of Culicoides species on UK equine premises
- Author
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Robin, M., Archer, D., Garros, C., Gardès, L., and Baylis, M.
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- 2014
- Full Text
- View/download PDF
15. The tree that hides the forest: Cryptic diversity and phylogenetic relationships in the Palaearctic vector Obsoletus/Scoticus Complex (Diptera: Ceratopogonidae) at the European level
- Author
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Mignotte, A., Garros, C., Gardès, L., Balenghien, T., Duhayon, M., Rakotoarivony, I., Tabourin, L., Poujol, L., Mathieu, B., Ibañez-Justicia, A., Deniz, A., Cvetkovikj, A., Purse, B.V., Ramilo, D.W., Stougiou, D., Werner, D., Pudar, D., Petric, D., Veronesi, E., Jacobs, F., Kampen, H., Pereira Da Fonseca, I., Lucientes, J., Navarro, J., De La Puente, J.M., Stefanovska, J., Searle, K.R., Khallaayoune, K., Culverwell, C.L., Larska, M., Bourquia, M., Goffredo, M., Bisia, M., England, M., Robin, M., Quaglia, M., Miranda-Chueca, M.Á., Bødker, R., Estrada-Penã, R., Carpenter, S., Tchakarova, S., Boutsini, S., Sviland, S., Schäfer, S.M., Ozolina¸, Seglina¸, Vatansever, Z., and Huber, K.
- Abstract
Background: Culicoides obsoletus is an abundant and widely distributed Holarctic biting midge species, involved in the transmission of bluetongue virus (BTV) and Schmallenberg virus (SBV) to wild and domestic ruminants. Females of this vector species are often reported jointly with two morphologically very close species, C. scoticus and C. montanus, forming the Obsoletus/Scoticus Complex. Recently, cryptic diversity within C. obsoletus was reported in geographically distant sites. Clear delineation of species and characterization of genetic variability is mandatory to revise their taxonomic status and assess the vector role of each taxonomic entity. Our objectives were to characterize and map the cryptic diversity within the Obsoletus/Scoticus Complex. Methods: Portion of the cox1 mitochondrial gene of 3763 individuals belonging to the Obsoletus/Scoticus Complex was sequenced. Populations from 20 countries along a Palaearctic Mediterranean transect covering Scandinavia to Canary islands (North to South) and Canary islands to Turkey (West to East) were included. Genetic diversity based on cox1 barcoding was supported by 16S rDNA mitochondrial gene sequences and a gene coding for ribosomal 28S rDNA. Species delimitation using a multi-marker methodology was used to revise the current taxonomic scheme of the Obsoletus/Scoticus Complex. Results: Our analysis showed the existence of three phylogenetic clades (C. obsoletus clade O2, C. obsoletus clade dark and one not yet named and identified) within C. obsoletus. These analyses also revealed two intra-specific clades within C. scoticus and raised questions about the taxonomic status of C. montanus. Conclusions: To our knowledge, our study provides the first genetic characterization of the Obsoletus/Scoticus Complex on a large geographical scale and allows a revision of the current taxonomic classification for an important group of vector species of livestock viruses in the Palaearctic region.[Figure not available: See fulltext.]
- Published
- 2020
16. Composição bromatológica de silagens de milho comerciais produzidas no Brasil
- Author
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Faria, T.F.R., Pinese, F., Gimenes, F.M.A., Demarchi, J.A.A.A., Campos, F.P., Premazzi, L.M., Mattos, W.T., Gardès, L., Faria, T.F.R., Pinese, F., Gimenes, F.M.A., Demarchi, J.A.A.A., Campos, F.P., Premazzi, L.M., Mattos, W.T., and Gardès, L.
- Abstract
The objective of this work was to perform the exploratory analysis of the chemical composition results and the use of models to estimate the total digestible nutrients of the corn silage samples generated from 11 years of commercial analyzes of the data bank of the Animal Nutrition Laboratory of the Instituto de Zootecnia (IZ), in Nova Odessa, SP, Brazil. As a criterion, samples of corn silage has no additives, 220 samples in the periods from 2004 to 2015 were grouped in four triennia. These were characterized by their chemical composition through descriptive statistical analysis, Pearson correlations and the use of NDT estimation models calculated through four models of equations: one from Clemson University, one according Harlan and two according Kearl (1 and 2). The nutritional value of corn silage samples was of medium quality, with NDF values (49.2 to 57.2% of MS) above the ideal. All the equations could be used to estimate the NDT (variation of 54.3 to 67.0 in the triennia), Kearl 1 and Clemson showed the highest and the lowest variation between the triennia, respectively. The increase in nutrient value and NDT in triennial 3 and 4 indicates improvement in silage quality, Objetivou-se fazer a análise exploratória dos resultados bromatológicos e uso de modelos para estimativa de nutrientes digestíveis totais das amostras de silagem de milho gerados a partir de 12 anos de análises comerciais do banco de dados do Laboratório de Nutrição Animal do Instituto de Zootecnia (IZ), em Nova Odessa, SP, Brasil. Como critério, utilizou-se dados de amostras de silagens de milho sem nenhum tipo de aditivos presentes no banco de dados do laboratório, somando 220 amostras nos períodos de 2004 a 2015 e agrupados em quatro triênios. Estes foram caracterizados quanto à sua composição bromatológica através da análise estatística descritiva, correlações de Pearson e pela utilização de modelos de estimativas de NDT calculado através de quatro modelos de equações: uma da Universidade de Clemson, uma segundo Harlan e duas segundo Kearl (1 e 2). O valor nutricional das amostras de silagens de milho mostrou-se de qualidade mediana, com valores de FDN (49,2 a 57,2% da MS) acima do ideal. Todas as equações puderam ser utilizadas na estimativa do NDT (variação de 54,3 a 67,0 nos triênios) sendo que a de Kearl 1 e Clemson apresentaram a maior e a menor variação entre os triênios, respectivamente. O aumento do valor nutritivo e de NDT nos triênios 3 e 4 indica melhoria na qualidade da silagem.
- Published
- 2020
17. Chemical composition of commercial corn silage produced in Brazil
- Author
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Faria, T.F.R., Pinese, F., Gimenes, F.M.A., Demarchi, J.J.A.A., Campos, F.P., Premazzi, L.M., Mattos, W.T., Gardès, L., Faria, T.F.R., Pinese, F., Gimenes, F.M.A., Demarchi, J.J.A.A., Campos, F.P., Premazzi, L.M., Mattos, W.T., and Gardès, L.
- Abstract
The objective was to perform the exploratory analysis of the chemical composition results and the use of models to estimate the total digestible nutrients of the corn silage samples generated from 12 years of commercial analyzes of the Animal Nutrition Laboratory of the Instituto de Zootecnia (IZ), in Nova Odessa, SP, Brazil. As a criterion, samples of corn silage had no additives, 220 samples in the periods from 2004 to 2015 were grouped in four triennia. These were characterized by their chemical composition through descriptive statistical analysis, Pearson correlations and the use of TDN estimation models, using four models of equations: one from Clemson University, one according Harlan and two according Kearl (1 and 2). The nutritional value of corn silage samples was of medium quality, with NDF values (49.2 to 57.2% of MS) above the ideal. All the equations could be used to estimate the NDT (variation of 54.3 to 67.0% in the triennia), Kearl 1 and Clemson showed the highest and the lowest variation between the triennia, respectively. The increase in nutrient value and TDN in triennial 3 and 4 indicates improvement in silage quality., Objetivou-se realizar a análise exploratória dos resultados bromatológicos e uso de modelos para estimativa de nutrientes digestíveis totais de amostras de silagens de milho, por meio dos dados gerados a partir de 12 anos de análises comerciais do Laboratório de Nutrição Animal do Instituto de Zootecnia (IZ), em Nova Odessa, SP, Brasil. Como critério, utilizaram-se dados de amostras de silagens de milho sem nenhum tipo de aditivos, somando 220 amostras nos períodos de 2004 a 2015 e agrupados em quatro triênios. Estes foram caracterizados quanto à sua composição bromatológica através de análise estatística descritiva, correlações de Pearson e pela utilização de modelos de estimativas de NDT, utilizando-se quatro modelos de equações: uma da Universidade de Clemson, uma segundo Harlan e duas segundo Kearl (1 e 2). O valor nutricional das amostras de silagens de milho mostrou-se de qualidade mediana, com valores de FDN (49,2 a 57,2% da MS) acima do ideal de 37 a 45% da MS. Todas as equações puderam ser utilizadas na estimativa do NDT (variação de 54,3 a 67,0% nos triênios) sendo que a de Kearl 1 e Clemson apresentaram a maior e a menor variação entre os triênios, respectivamente. O aumento do valor nutritivo e de NDT nos triênios 3 e 4 indica melhoria na qualidade da silagem.
- Published
- 2020
18. Host preferences of Palaearctic Culicoides biting midges: implications for transmission of orbiviruses
- Author
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VIENNET, E., GARROS, C., GARDÈS, L., RAKOTOARIVONY, I., ALLÈNE, X., LANCELOT, R., CROCHET, D., MOULIA, C., BALDET, T., and BALENGHIEN, T.
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- 2013
- Full Text
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19. Natural Wolbachia infection across Guadeloupe mosquito populations
- Author
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Pagès, N., Re, J., Aprelon, Rosalie, Le Bihan, M., Gardès, L., Venail, R., Jacquet-Cretides, L., Giraud-Girard, K., Meyer, D.F., Animal, Santé, Territoires, Risques et Ecosystèmes (UMR ASTRE), Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), FALCO, Eliane, and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)
- Subjects
[SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health ,[SDV.BA] Life Sciences [q-bio]/Animal biology ,[SDV.BA]Life Sciences [q-bio]/Animal biology ,fungi ,parasitic diseases ,[SDV.EE.SANT] Life Sciences [q-bio]/Ecology, environment/Health ,bacteria ,biochemical phenomena, metabolism, and nutrition ,reproductive and urinary physiology - Abstract
Mosquitoes have the potential to transmit a large variety of pathogens to humans and other vertebrate hosts. No effective technique has been found to properly control and reduce the density of mosquito populations in a sustainable manner. Endosymbionts, particularly Wolbachia, represent a promising alternative to control medically important mosquito species and reduce their disease transmission capacity. The presence of Wolbachia endosymbionts was screened in mosquito populations of Guadeloupe Island (French West Indies). Mosquitoes were collected across 39 sites that were representative of major biotopes in Guadeloupe and were categorized into natural, rural and urban landscapes. Natural and rural landscapes showed higher mosquito species diversity when compared to urban landscapes. The presence of Wolbachia was revealed by real-time PCR in six mosquito species belonging to five genera: Deinocerites, Culex, Mansonia, Ochlerotatus and Uranotaenia. Wolbachia was detected in mosquitoes collected at sites attributed to the three landscape categories. However prevalence of Wolbachia infection was heterogeneous among mosquito species and collection sites. Phylogeny based on Wolbachia surface protein (wsp) sequences showed that Wolbachia isolates from field collected mosquitoes were distributed across three major clades belonging to Wolbachia supergroups A and B. Some of the Wolbachia wsp sequences represent new haplotypes. The presence of Wolbachia in Neotropical mosquito species is expected to trigger new research on the control of mosquitoes and the pathogens they transmit. In mosquitoes, Wolbachia is able to reduce the fitness and pathogen transmission, thus being a potential target for population reduction and replacement strategies. Posterropods in terms of public and veterinary health.
- Published
- 2019
20. Phylogenetic relationships and molecular delimitation of CulicoidesLatreille (Diptera: Ceratopogonidae) species in the Afrotropical region: interest for the subgenus Avaritia
- Author
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BAKHOUM, M. T., primary, LABUSCHAGNE, K., additional, HUBER, K., additional, FALL, M., additional, MATHIEU, B., additional, VENTER, G., additional, GARDÈS, L., additional, BALDET, T., additional, BOUYER, J., additional, FALL, A. G., additional, GIMONNEAU, G., additional, and GARROS, C., additional
- Published
- 2017
- Full Text
- View/download PDF
21. Schmallenberg virus in Culicoides Latreille (Diptera: Ceratopogonidae) populations in France during 2011-2012 outbreak
- Author
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Ségard, A., primary, Gardès, L., additional, Jacquier, E., additional, Grillet, C., additional, Mathieu, B., additional, Rakotoarivony, I., additional, Setier-Rio, M.-L., additional, Chavernac, D., additional, Cêtre-Sossah, C., additional, Balenghien, T., additional, and Garros, C., additional
- Published
- 2017
- Full Text
- View/download PDF
22. Blood-feeding patterns of horse flies in the French Pyrenees
- Author
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Baldacchino, F., Gardès, L., De Stordeur, E., Jay-Robert, P., and Garros, C.
- Published
- 2014
- Full Text
- View/download PDF
23. First record ofStegomyia albopicta(= Aedes albopictus) in Morocco: a major threat to public health in North Africa?
- Author
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BENNOUNA, A., primary, BALENGHIEN, T., additional, EL RHAFFOULI, H., additional, SCHAFFNER, F., additional, GARROS, C., additional, GARDÈS, L., additional, LHOR, Y., additional, HAMMOUMI, S., additional, CHLYEH, G., additional, and FASSI FIHRI, O., additional
- Published
- 2016
- Full Text
- View/download PDF
24. Morphometric discrimination of two sympatric sibling species in the Palaearctic region, Culicoides obsoletus Meigen and C. scoticus Downes & Kettle (Diptera: Ceratopogonidae), vectors of bluetongue and Schmallenberg viruses
- Author
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Kluiters, G., primary, Pagès, N., additional, Carpenter, S., additional, Gardès, L., additional, Guis, H., additional, Baylis, M., additional, and Garros, C., additional
- Published
- 2016
- Full Text
- View/download PDF
25. Foraging range of arthropods with veterinary interest: New insights for Afrotropical Culicoides biting midges (Diptera: Ceratopogonidae) using the ring method
- Author
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Bakhoum, M.T., primary, Fall, M., additional, Seck, M.T., additional, Gardès, L., additional, Fall, A.G., additional, Diop, M., additional, Mall, I., additional, Balenghien, T., additional, Baldet, T., additional, Gimonneau, G., additional, Garros, C., additional, and Bouyer, J., additional
- Published
- 2016
- Full Text
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26. First overview of the Culicoides Latreille (Diptera: Ceratopogonidae) livestock associated species of Reunion Island, Indian Ocean
- Author
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Desvars, Amélie, Grimaud, Y., Guis, H., Esnault, O., Allène, X., Gardès, L., Balenghien, T., Baldet, T., Delécolle, J.C., Garros, C., Desvars, Amélie, Grimaud, Y., Guis, H., Esnault, O., Allène, X., Gardès, L., Balenghien, T., Baldet, T., Delécolle, J.C., and Garros, C.
- Abstract
This study establishes the first faunistic inventory of livestock associated Culicoides (Diptera: Ceratopogonidae) species of Reunion Island (Indian Ocean), where bluetongue and epizootic hemorrhagic disease are regularly recorded. Single night-catches were performed at 41 sites using light suction traps at altitudes ranging from 0 to 1525. m, from March to April 2005. Five species were recorded: Culicoides imicola, Culicoides bolitinos, Culicoides enderleini, Culicoides grahamii, and Culicoides kibatiensis, among which at least the first three species are known to be involved in virus transmission to ruminants and equids. This is the first record of C. bolitinos, C. kibatiensis, and C. enderleini on the island. C. imicola was the most abundant species along the sea coast. C. bolitinos was more abundant inland and on two sites on the east coast. C. kibatiensis and C. grahamii were less abundant than the other three species and limited to two foci. Spatial distribution analysis of the different species showed that C. bolitinos, C. enderleini and C. imicola were collected at low altitudes, while the other two species were found at higher altitude. A morphological identification key for adult females and males is given, as well as cytochrome oxydase subunit I sequences. Phylogenetic reconstructions showed a clear divergence between C. bolitinos from Reunion Island and mainland Africa. This monograph will help to identify the Culicoides species in the poorly known entomological fauna of the south-western Indian Ocean region.
- Published
- 2015
- Full Text
- View/download PDF
27. Phylogenetic relationships and molecular delimitation of Culicoides Latreille (Diptera: Ceratopogonidae) species in the Afrotropical region: interest for the subgenus Avaritia.
- Author
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BAKHOUM, M. T., LABUSCHAGNE, K., HUBER, K., FALL, M., MATHIEU, B., VENTER, G., GARDÈS, L., BALDET, T., BOUYER, J., FALL, A. G., GIMONNEAU, G., and GARROS, C.
- Subjects
PHYLOGENY ,MOLECULAR biology ,CULICOIDES ,CLASSIFICATION of insects ,MITOCHONDRIAL DNA ,NUCLEAR DNA ,BAYESIAN analysis ,MAXIMUM likelihood statistics - Abstract
Copyright of Systematic Entomology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
28. Schmallenberg virus in <italic>Culicoides</italic> Latreille (Diptera: Ceratopogonidae) populations in France during 2011‐2012 outbreak.
- Author
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Ségard, A., Gardès, L., Jacquier, E., Grillet, C., Mathieu, B., Rakotoarivony, I., Setier‐Rio, M.‐L., Chavernac, D., Cêtre‐Sossah, C., Balenghien, T., and Garros, C.
- Subjects
- *
CULICOIDES , *SCHMALLENBERG virus , *INSECT populations , *EPIDEMIOLOGY , *REVERSE transcriptase polymerase chain reaction - Abstract
Summary: Following the emergence of the Schmallenberg virus (SBV) in 2011 in Germany and its rapid spread in Europe,
Culicoides (Diptera: Ceratopogonidae) collected through the French surveillance network were analysed in order to record the presence of virus genome into species diversity collected, to assess the minimum infectious rates (MIR) and the virus circulation dynamics inCulicoides populations. Two vector activity periods were selected (2011, August to October, 53 sites and 2012, June to October, 35 sites) corresponding to 704 night collections. A total of 29,285 individual midges covering at least 50 species were tested either in pools of maximum 50 females or individually (forCulicoides obsoletus /Culicoides scoticus ) using real‐time RT‐PCR. Nine species were found SBV positive (C. obsoletus ,C. scoticus ,Culicoides chiopterus ,Culicoides dewulfi ,Culicoides imicola ,Culicoides pulicaris ,Culicoides newsteadi ,Culicoides lupicaris andCulicoides nubeculosus ) with overall MIR ranging from 0.2% to 4.2%. While theCulicoides nubeculosus laboratory strain is generally considered to have only low vector competence for viruses, interestingly, field‐caughtC. nubeculosus specimens were found positive twice for SBV. The first SBV‐positive pool was recorded in August 2011 in north‐eastern France, dating the virus circulation in France 5 months earlier than the first recorded congenital malformations and 2 months earlier than the former recorded date based on retrospective serological data. The MIR were maximum in October 2011, and in July 2012 according to dates of virus arrival in the studied areas. Moreover, our study also showed that virus circulation could be locally intense with infection rate (IR) reaching up to 16% forC. obsoletus /C. scoticus in July 2012 in one site of western France. This retrospective study demonstrates the importance of large‐scale analysis to describe the spatio‐temporal dynamics of virus circulation. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
29. First overview of the Culicoides Latreille (Diptera: Ceratopogonidae) livestock associated species of Reunion Island, Indian Ocean
- Author
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Desvars, A., primary, Grimaud, Y., additional, Guis, H., additional, Esnault, O., additional, Allène, X., additional, Gardès, L., additional, Balenghien, T., additional, Baldet, T., additional, Delécolle, J.C., additional, and Garros, C., additional
- Published
- 2015
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30. Molecular identification of Palaearctic Culicoides blood meals from different localities in France
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Garros, Claire, Gardès, L, Viennet, Elvina, Allene, Xavier, Rakotoarivony, Ignace, Balenghien, Thomas, ProdInra, Migration, and Inconnu
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Bétail ,[SDV]Life Sciences [q-bio] ,Sang ,Peste équine africaine ,L73 - Maladies des animaux ,Bluetongue ,SF1-1100 ,Virus bluetongue ,Fièvre catarrhale ovine ,Culicoides ,Animal domestique ,Animal culture ,[SDV] Life Sciences [q-bio] ,identification ,Fièvre catarrhale du mouton ,L72 - Organismes nuisibles des animaux ,Genre humain ,Repas de sang - Abstract
Culicoides are small biting midges involved worldwide in bluetongue and African horse sickness transmission. Feeding behaviour as well as spatial and temporal dynamics of trophic behaviour of Culicoides is unknown at the specific level for Palaearctic species. Multiplex allele-specific polymerase chain reaction (PCR) assays were used to identify the blood meal source of five main Palaearctic species. Species-specific primers of potential hosts (cow, goat, sheep, human, cat, dog, horse) were derived from vertebrate mitochondrial cytochrome b. Two different multiplex assays served to identify blood meals from livestock or domestic fauna, and to determine whether multiple blood meals had been taken (gonotrophic concordance). Moreover, this method helped to identify specimens at the specific level. The first results highlight the interest of this valuable tool combined with species identification assays, and suggest that Culicoides species may have an opportunistic behaviour regarding host distribution and density. Future studies will focus on the temporal dynamics of trophic behaviour. (Texte intégral)
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- 2010
31. Towards the PCR-based identification of Palaearctic Culicoides biting midges (Diptera: Ceratopogonidae): results from an international ring trial targeting fourspecies of the subgenus Avaritia.
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Garros, C., Balenghien, T., Carpenter, S., Delécolle, J.C., Meiswinkel, R., Pédarrieu, A., Rakotoarivony, I., Gardès, L., Golding, N., Barber, J., Miranda, M., Borràs Borràs, D., Goffredo, M., Monaco, F., Pagès, N., Sghaier, S., Hammami, S., Calvo, J.H., Lucientes, J., Geysen, D., de Deken, G., Sarto i Monteys, V., Schwenkenbecher, J., Kampen, H., Hoffmann, B., Lehman, K., Werner, D., Baldet, T., Lancelot, R., Cêtre-Sossah, C., Garros, C., Balenghien, T., Carpenter, S., Delécolle, J.C., Meiswinkel, R., Pédarrieu, A., Rakotoarivony, I., Gardès, L., Golding, N., Barber, J., Miranda, M., Borràs Borràs, D., Goffredo, M., Monaco, F., Pagès, N., Sghaier, S., Hammami, S., Calvo, J.H., Lucientes, J., Geysen, D., de Deken, G., Sarto i Monteys, V., Schwenkenbecher, J., Kampen, H., Hoffmann, B., Lehman, K., Werner, D., Baldet, T., Lancelot, R., and Cêtre-Sossah, C.
- Abstract
Background: Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are biological vectors of internationally important arboviruses. To understand the role of Culicoides in the transmission of these viruses, it is essential to correctly identify the species involved. Within the western Palaearctic region, the main suspected vector species, C. obsoletus, C. scoticus, C. dewulfi and C. chiopterus, have similar wing patterns, which makes it difficult to separate and identify them correctly. Methods: In this study, designed as an inter-laboratory ring trial with twelve partners from Europe and North Africa, we assess four PCR-based assays which are used routinely to differentiate the four species of Culicoides listed above. The assays based on mitochondrial or ribosomal DNA or microarray hybridisation were tested using aliquots of Culicoides DNA (extracted using commercial kits), crude lysates of ground specimens and whole Culicoides (265 individuals), and non-Culicoides Ceratopogonidae (13 individuals) collected from across Europe. Results: A total of 800 molecular assays were implemented. The in-house assays functioned effectively, although specificity and sensitivity varied according to the molecular marker and DNA extraction method used. The Obsoletus group specificity was overall high (95-99%) while the sensitivity varied greatly (59.6-100%). DNA extraction methods impacted the sensitivity of the assays as well as the type of sample used as template for the DNA extraction. Conclusions: The results are discussed in terms of current use of species diagnostic assays and the future development of molecular tools for the rapid differentiation of cryptic Culicoides species.
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- 2014
32. Host preferences of Palaearctic Culicoides biting midges: implications for transmission of orbiviruses
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VIENNET, E., primary, GARROS, C., additional, GARDÈS, L., additional, RAKOTOARIVONY, I., additional, ALLÈNE, X., additional, LANCELOT, R., additional, CROCHET, D., additional, MOULIA, C., additional, BALDET, T., additional, and BALENGHIEN, T., additional
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- 2012
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33. High dispersal capacity of Culicoides obsoletus (Diptera: Ceratopogonidae), vector of bluetongue and Schmallenberg viruses, revealed by landscape genetic analyses.
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Mignotte A, Garros C, Dellicour S, Jacquot M, Gilbert M, Gardès L, Balenghien T, Duhayon M, Rakotoarivony I, de Wavrechin M, and Huber K
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- Animals, Bluetongue virus physiology, Cattle parasitology, Ceratopogonidae physiology, Europe, Feeding Behavior, Female, France, Gene Flow, Genotype, Insect Vectors physiology, Microsatellite Repeats, Orthobunyavirus physiology, Population Dynamics, Seasons, Bluetongue transmission, Bunyaviridae Infections transmission, Ceratopogonidae genetics, Ceratopogonidae virology, Environment, Insect Vectors virology
- Abstract
Background: In the last two decades, recurrent epizootics of bluetongue virus and Schmallenberg virus have been reported in the western Palearctic region. These viruses affect domestic cattle, sheep, goats and wild ruminants and are transmitted by native hematophagous midges of the genus Culicoides (Diptera: Ceratopogonidae). Culicoides dispersal is known to be stratified, i.e. due to a combination of dispersal processes occurring actively at short distances and passively or semi-actively at long distances, allowing individuals to jump hundreds of kilometers., Methods: Here, we aim to identify the environmental factors that promote or limit gene flow of Culicoides obsoletus, an abundant and widespread vector species in Europe, using an innovative framework integrating spatial, population genetics and statistical approaches. A total of 348 individuals were sampled in 46 sites in France and were genotyped using 13 newly designed microsatellite markers., Results: We found low genetic differentiation and a weak population structure for C. obsoletus across the country. Using three complementary inter-individual genetic distances, we did not detect any significant isolation by distance, but did detect significant anisotropic isolation by distance on a north-south axis. We employed a multiple regression on distance matrices approach to investigate the correlation between genetic and environmental distances. Among all the environmental factors that were tested, only cattle density seems to have an impact on C. obsoletus gene flow., Conclusions: The high dispersal capacity of C. obsoletus over land found in the present study calls for a re-evaluation of the impact of Culicoides on virus dispersal, and highlights the urgent need to better integrate molecular, spatial and statistical information to guide vector-borne disease control.
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- 2021
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34. Correction to: The tree that hides the forest: cryptic diversity and phylogenetic relationships in the Palaearctic vector Obsoletus/Scoticus complex (Diptera: Ceratopogonidae) at the European level.
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Mignotte A, Garros C, Gardès L, Balenghien T, Duhayon M, Rakotoarivony I, Tabourin L, Poujol L, Mathieu B, Ibañez-Justicia A, Deniz A, Cvetkovikj A, Purse BV, Ramilo DW, Stougiou D, Werner D, Pudar D, Petrić D, Veronesi E, Jacobs F, Kampen H, da Fonseca IP, Lucientes J, Navarro J, la Puente JM, Stefanovska J, Searle KR, Khallaayoune K, Lorna Culverwell C, Larska M, Bourquia M, Goffredo M, Bisia M, England M, Robin M, Quaglia M, Miranda-Chueca MÁ, Bødker R, Estrada-Peña R, Carpenter S, Tchakarova S, Boutsini S, Sviland S, Schäfer SM, Ozoliņa Z, Segliņa Z, Vatansever Z, and Huber K
- Abstract
An amendment to this paper has been published and can be accessed via the original article.
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- 2020
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35. The tree that hides the forest: cryptic diversity and phylogenetic relationships in the Palaearctic vector Obsoletus/Scoticus Complex (Diptera: Ceratopogonidae) at the European level.
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Mignotte A, Garros C, Gardès L, Balenghien T, Duhayon M, Rakotoarivony I, Tabourin L, Poujol L, Mathieu B, Ibañez-Justicia A, Deniz A, Cvetkovikj A, Purse BV, Ramilo DW, Stougiou D, Werner D, Pudar D, Petrić D, Veronesi E, Jacobs F, Kampen H, Pereira da Fonseca I, Lucientes J, Navarro J, de la Puente JM, Stefanovska J, Searle KR, Khallaayoune K, Culverwell CL, Larska M, Bourquia M, Goffredo M, Bisia M, England M, Robin M, Quaglia M, Miranda-Chueca MÁ, Bødker R, Estrada-Peña R, Carpenter S, Tchakarova S, Boutsini S, Sviland S, Schäfer SM, Ozoliņa Z, Segliņa Z, Vatansever Z, and Huber K
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- Animals, Ceratopogonidae virology, Cyclooxygenase 1 genetics, DNA Barcoding, Taxonomic, Europe, Female, Geography, Insect Vectors virology, Livestock virology, Sequence Analysis, DNA, Ceratopogonidae classification, Genetic Variation, Insect Vectors classification, Phylogeny
- Abstract
Background: Culicoides obsoletus is an abundant and widely distributed Holarctic biting midge species, involved in the transmission of bluetongue virus (BTV) and Schmallenberg virus (SBV) to wild and domestic ruminants. Females of this vector species are often reported jointly with two morphologically very close species, C. scoticus and C. montanus, forming the Obsoletus/Scoticus Complex. Recently, cryptic diversity within C. obsoletus was reported in geographically distant sites. Clear delineation of species and characterization of genetic variability is mandatory to revise their taxonomic status and assess the vector role of each taxonomic entity. Our objectives were to characterize and map the cryptic diversity within the Obsoletus/Scoticus Complex., Methods: Portion of the cox1 mitochondrial gene of 3763 individuals belonging to the Obsoletus/Scoticus Complex was sequenced. Populations from 20 countries along a Palaearctic Mediterranean transect covering Scandinavia to Canary islands (North to South) and Canary islands to Turkey (West to East) were included. Genetic diversity based on cox1 barcoding was supported by 16S rDNA mitochondrial gene sequences and a gene coding for ribosomal 28S rDNA. Species delimitation using a multi-marker methodology was used to revise the current taxonomic scheme of the Obsoletus/Scoticus Complex., Results: Our analysis showed the existence of three phylogenetic clades (C. obsoletus clade O2, C. obsoletus clade dark and one not yet named and identified) within C. obsoletus. These analyses also revealed two intra-specific clades within C. scoticus and raised questions about the taxonomic status of C. montanus., Conclusions: To our knowledge, our study provides the first genetic characterization of the Obsoletus/Scoticus Complex on a large geographical scale and allows a revision of the current taxonomic classification for an important group of vector species of livestock viruses in the Palaearctic region.
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- 2020
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36. Red deer ( Cervus elaphus ) Did Not Play the Role of Maintenance Host for Bluetongue Virus in France: The Burden of Proof by Long-Term Wildlife Monitoring and Culicoides Snapshots.
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Rossi S, Balenghien T, Viarouge C, Faure E, Zanella G, Sailleau C, Mathieu B, Delécolle JC, Ninio C, Garros C, Gardès L, Tholoniat C, Ariston A, Gauthier D, Mondoloni S, Barboiron A, Pellerin M, Gibert P, Novella C, Barbier S, Guillaumat E, Zientara S, Vitour D, and Bréard E
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- Animals, Animals, Domestic virology, Antibodies, Neutralizing, Antibodies, Viral, Bluetongue epidemiology, Bluetongue transmission, Bluetongue virology, Bluetongue virus immunology, Ceratopogonidae classification, Disease Outbreaks, Female, France epidemiology, Livestock virology, Male, Ruminants virology, Vector Borne Diseases virology, Animals, Wild virology, Bluetongue virus physiology, Ceratopogonidae virology, Deer virology, Disease Reservoirs virology
- Abstract
Bluetongue virus (BTV) is a Culicoides -borne pathogen infecting both domestic and wild ruminants. In Europe, the Red Deer ( Cervus elaphus ) (RD) is considered a potential BTV reservoir, but persistent sylvatic cycle has not yet been demonstrated. In this paper, we explored the dynamics of BTV1 and BTV8 serotypes in the RD in France, and the potential role of that species in the re-emergence of BTV8 in livestock by 2015 (i.e., 5 years after the former last domestic cases). We performed 8 years of longitudinal monitoring (2008-2015) among 15 RD populations and 3065 individuals. We compared Culicoides communities and feeding habits within domestic and wild animal environments (51,380 samples). Culicoides diversity (>30 species) varied between them, but bridge-species able to feed on both wild and domestic hosts were abundant in both situations. Despite the presence of competent vectors in natural environments, BTV1 and BTV8 strains never spread in RD along the green corridors out of the domestic outbreak range. Decreasing antibody trends with no PCR results two years after the last domestic outbreak suggests that seropositive young RD were not recently infected but carried maternal antibodies. We conclude that RD did not play a role in spreading or maintaining BTV in France.
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- 2019
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37. Update of the species checklist of Culicoides Latreille, 1809 biting midges (Diptera: Ceratopogonidae) of Morocco.
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Bourquia M, Garros C, Rakotoarivony I, Gardès L, Huber K, Boukhari I, Delécolle JC, Baldet T, Mignotte A, Lhor Y, Khallaayoune K, and Balenghien T
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- Animals, Ceratopogonidae anatomy & histology, Ceratopogonidae genetics, Morocco, Biodiversity, Ceratopogonidae classification, Ceratopogonidae growth & development
- Abstract
Background: Investigations of Culicoides fauna, including inventories, were carried out in Morocco at different periods after the country had faced major bluetongue and African horse sickness outbreaks. However, no comprehensive reference publication has provided a clear overview of the Culicoides species diversity. This study reviewed available data on Culicoides biting midge species in Morocco from 1968 to 2015 (published and grey literature in French and English) in order to revise the current checklist, in light of state of the art taxonomic and systematic knowledge, and confirmed the checklist with morphological and molecular identifications of specimens collected from the region of Rabat., Methods: Literature related to Culicoides collections in Morocco was collated. Authors were contacted to obtain raw data and additional information for the collections. Fresh Culicoides material was collected and examined from two sites around Rabat, the capital of Morocco. Each collected individual was examined and morphologically identified, if possible, to the species level. In addition, molecular identification was performed to separate closely related species, to confirm difficult morphological identifications and to confirm new species records., Results: A total of 6121 individuals of Culicoides spp. were collected and analyzed and at least 17 species were identified: C. cataneii/C. gejgelensis, C. circumscriptus, C. fagineus, C. festivipennis, C. imicola, C. jumineri, C. kingi, C. longipennis, C. montanus, C. newsteadi, C. obsoletus, C. paolae, C. parotti, C. puncticollis, C. sahariensis, C. scoticus and C. subfagineus. Seven species were confirmed using phylogenetic analyses. Two new species records for Morocco are reported: C. paolae and C. subfagineus., Conclusions: The Moroccan fauna of Culicoides now includes 54 valid species. Further work would certainly increase this total, as one of the clades we identified was not affiliated to any described and valid species.
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- 2019
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38. DNA barcoding and molecular identification of field-collected Culicoides larvae in the Niayes area of Senegal.
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Bakhoum MT, Sarr M, Fall AG, Huber K, Fall M, Sembène M, Seck MT, Labuschagne K, Gardès L, Ciss M, Gimonneau G, Bouyer J, Baldet T, and Garros C
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- Animals, Biodiversity, Ceratopogonidae genetics, Cyclooxygenase 1 genetics, Insect Proteins genetics, Insect Vectors genetics, Larva genetics, Senegal, Ceratopogonidae classification, DNA Barcoding, Taxonomic, Insect Vectors classification, Larva classification
- Abstract
Background: Biting midge species of the genus Culicoides Latreille (Diptera: Ceratopogonidae) comprise more than 1300 species distributed worldwide. Several species of Culicoides are vectors of various viruses that can affect animals, like the African horse sickness virus (AHSV), known to be endemic in sub-Saharan Africa. The ecological and veterinary interest of Culicoides emphasizes the need for rapid and reliable identification of vector species. However, morphology-based identification has limitations and warrants integration of molecular data. DNA barcoding based on the mitochondrial gene cytochrome c oxidase subunit 1 (cox1) is used as a rapid and authentic tool for species identification in a wide variety of animal taxa across the globe. In this study, our objectives were as follows: (i) establish a reference DNA barcode for Afrotropical Culicoides species; (ii) assess the accuracy of cox1 in identifying Afrotropical Culicoides species; and (iii) test the applicability of DNA barcoding for species identification on a large number of samples of Culicoides larvae from the Niayes area of Senegal, West Africa., Results: A database of 230 cox1 sequences belonging to 42 Afrotropical Culicoides species was found to be reliable for species-level assignments, which enabled us to identify cox1 sequences of Culicoides larvae from the Niayes area of Senegal. Of the 933 cox1 sequences of Culicoides larvae analyzed, 906 were correctly identified by their barcode sequences corresponding to eight species of Culicoides. A total of 1131 cox1 sequences of adult and larval Culicoides were analyzed, and a hierarchical increase in mean divergence was observed according to two taxonomic levels: within species (mean = 1.92%, SE = 0.00), and within genus (mean = 17.82%, SE = 0.00)., Conclusions: Our study proves the efficiency of DNA barcoding for studying Culicoides larval diversity in field samples. Such a diagnostic tool offers great opportunities for investigating Culicoides immature stages ecology and biology, a prerequisite for the implementation of eco-epidemiological studies to better control AHSV in the Niayes region of Senegal, and more generally in sub-Saharan Africa.
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- 2018
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39. How do species, population and active ingredient influence insecticide susceptibility in Culicoides biting midges (Diptera: Ceratopogonidae) of veterinary importance?
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Venail R, Lhoir J, Fall M, del Río R, Talavera S, Labuschagne K, Miranda M, Pagès N, Venter G, Rakotoarivony I, Allène X, Scheid B, Gardès L, Gimonneau G, Lancelot R, Garros C, Cêtre-Sossah C, Balenghien T, Carpenter S, and Baldet T
- Subjects
- Africa, Animals, Biological Assay, Europe, Insect Vectors classification, Insect Vectors drug effects, Organophosphates pharmacology, Parasitic Sensitivity Tests, Pyrethrins pharmacology, Survival Analysis, Ceratopogonidae classification, Ceratopogonidae drug effects, Insecticides pharmacology
- Abstract
Background: Culicoides biting midges are biological vectors of internationally important arboviruses of livestock and equines. Insecticides are often employed against Culicoides as a part of vector control measures, but systematic assessments of their efficacy have rarely been attempted. The objective of the present study is to determine baseline susceptibility of multiple Culicoides vector species and populations in Europe and Africa to the most commonly used insecticide active ingredients. Six active ingredients are tested: three that are based on synthetic pyrethroids (alpha-cypermethrin, deltamethrin and permethrin) and three on organophosphates (phoxim, diazinon and chlorpyrifos-methyl)., Methods: Susceptibility tests were conducted on 29,064 field-collected individuals of Culicoides obsoletus Meigen, Culicoides imicola Kieffer and a laboratory-reared Culicoides nubeculosus Meigen strain using a modified World Health Organization assay. Populations of Culicoides were tested from seven locations in four different countries (France, Spain, Senegal and South Africa) and at least four concentrations of laboratory grade active ingredients were assessed for each population., Results: The study revealed that insecticide susceptibility varied at both a species and population level, but that broad conclusions could be drawn regarding the efficacy of active ingredients. Synthetic pyrethroid insecticides were found to inflict greater mortality than organophosphate active ingredients and the colony strain of C. nubeculosus was significantly more susceptible than field populations. Among the synthetic pyrethroids, deltamethrin was found to be the most toxic active ingredient for all species and populations., Conclusions: The data presented represent the first parallel and systematic assessment of Culicoides insecticide susceptibility across several countries. As such, they are an important baseline reference to monitor the susceptibility status of Culicoides to current insecticides and also to assess the toxicity of new active ingredients with practical implications for vector control strategies.
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- 2015
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40. Towards the PCR-based identification of Palaearctic Culicoides biting midges (Diptera: Ceratopogonidae): results from an international ring trial targeting four species of the subgenus Avaritia.
- Author
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Garros C, Balenghien T, Carpenter S, Delécolle JC, Meiswinkel R, Pédarrieu A, Rakotoarivony I, Gardès L, Golding N, Barber J, Miranda M, Borràs DB, Goffredo M, Monaco F, Pagès N, Sghaier S, Hammami S, Calvo JH, Lucientes J, Geysen D, De Deken G, Sarto I Monteys V, Schwenkenbecher J, Kampen H, Hoffmann B, Lehmann K, Werner D, Baldet T, Lancelot R, and Cêtre-Sossah C
- Subjects
- Animals, Ceratopogonidae classification, Ceratopogonidae physiology, Female, Male, Sensitivity and Specificity, Species Specificity, Ceratopogonidae genetics, DNA genetics, Polymerase Chain Reaction methods
- Abstract
Background: Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are biological vectors of internationally important arboviruses. To understand the role of Culicoides in the transmission of these viruses, it is essential to correctly identify the species involved. Within the western Palaearctic region, the main suspected vector species, C. obsoletus, C. scoticus, C. dewulfi and C. chiopterus, have similar wing patterns, which makes it difficult to separate and identify them correctly., Methods: In this study, designed as an inter-laboratory ring trial with twelve partners from Europe and North Africa, we assess four PCR-based assays which are used routinely to differentiate the four species of Culicoides listed above. The assays based on mitochondrial or ribosomal DNA or microarray hybridisation were tested using aliquots of Culicoides DNA (extracted using commercial kits), crude lysates of ground specimens and whole Culicoides (265 individuals), and non-Culicoides Ceratopogonidae (13 individuals) collected from across Europe., Results: A total of 800 molecular assays were implemented. The in-house assays functioned effectively, although specificity and sensitivity varied according to the molecular marker and DNA extraction method used. The Obsoletus group specificity was overall high (95-99%) while the sensitivity varied greatly (59.6-100%). DNA extraction methods impacted the sensitivity of the assays as well as the type of sample used as template for the DNA extraction., Conclusions: The results are discussed in terms of current use of species diagnostic assays and the future development of molecular tools for the rapid differentiation of cryptic Culicoides species.
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- 2014
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41. First record of Culicoides oxystoma Kieffer and diversity of species within the Schultzei group of Culicoides Latreille (Diptera: Ceratopogonidae) biting midges in Senegal.
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Bakhoum MT, Fall M, Fall AG, Bellis GA, Gottlieb Y, Labuschagne K, Venter GJ, Diop M, Mall I, Seck MT, Allène X, Diarra M, Gardès L, Bouyer J, Delécolle JC, Balenghien T, and Garros C
- Subjects
- Animals, Ceratopogonidae anatomy & histology, Female, Geography, Insect Vectors anatomy & histology, Insect Vectors classification, Insect Vectors genetics, Male, Phylogeny, Senegal, Ceratopogonidae classification, Ceratopogonidae genetics
- Abstract
The Schultzei group of Culicoides Latreille (Diptera: Ceratopogonidae) is distributed throughout Africa to northern Asia and Australasia and includes several potential vector species of livestock pathogens. The taxonomy of the species belonging to this species group is confounded by the wide geographical distribution and morphological variation exhibited by many species. In this work, morphological and molecular approaches were combined to assess the taxonomic validity of the species and morphological variants of the Schultzei group found in Senegal by comparing their genetic diversity with that of specimens from other geographical regions. The species list for Senegal was updated with four species: Culicoides kingi, C. oxystoma, C. enderleini and C. nevilli being recorded. This is the first record of C. oxystoma from Africa south of Sahara, and its genetic relationship with samples from Israel, Japan and Australia is presented. This work provides a basis for ecological studies of the seasonal and spatial dynamics of species of this species group that will contribute to better understanding of the epidemiology of the viruses they transmit.
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- 2013
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42. Host-seeking activity of bluetongue virus vectors: endo/exophagy and circadian rhythm of Culicoides in Western Europe.
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Viennet E, Garros C, Rakotoarivony I, Allène X, Gardès L, Lhoir J, Fuentes I, Venail R, Crochet D, Lancelot R, Riou M, Moulia C, Baldet T, and Balenghien T
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- Animals, Bluetongue prevention & control, Bluetongue virology, Bluetongue virus physiology, Circadian Rhythm physiology, Diptera classification, Diptera virology, Europe, Female, France, Host-Parasite Interactions, Host-Pathogen Interactions, Insect Bites and Stings physiopathology, Insect Vectors virology, Male, Seasons, Sheep, Species Specificity, Bluetongue transmission, Bluetongue virus growth & development, Diptera physiology, Insect Vectors physiology
- Abstract
Feeding success of free-living hematophagous insects depends on their ability to be active when hosts are available and to reach places where hosts are accessible. When the hematophagous insect is a vector of pathogens, determining the components of host-seeking behavior is of primary interest for the assessment of transmission risk. Our aim was to describe endo/exophagy and circadian host-seeking activity of Palaearctic Culicoides species, which are major biting pests and arbovirus vectors, using drop traps and suction traps baited with four sheep, as bluetongue virus hosts. Collections were carried out in the field, a largely-open stable and an enclosed stable during six collection periods of 24 hours in April/May, in late June and in September/October 2010 in western France. A total of 986 Culicoides belonging to 13 species, mainly C. brunnicans and C. obsoletus, was collected on animal baits. Culicoides brunnicans was clearly exophagic, whereas C. obsoletus was able to enter stables. Culicoides brunnicans exhibited a bimodal pattern of host-seeking activity with peaks just after sunrise and sunset. Culicoides obsoletus was active before sunset in spring and autumn and after sunset in summer, thus illustrating influence of other parameters than light, especially temperature. Description of host-seeking behaviors allowed us to discuss control strategies for transmission of Culicoides-borne pathogens, such as bluetongue virus. However, practical vector-control recommendations are difficult to provide because of the variation in the degree of endophagy and time of host-seeking activity.
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- 2012
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43. Adaptation of a species-specific multiplex PCR assay for the identification of blood meal source in Culicoides (Ceratopogonidae: Diptera): applications on Palaearctic biting midge species, vectors of Orbiviruses.
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Garros C, Gardès L, Allène X, Rakotoarivony I, Viennet E, Rossi S, and Balenghien T
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- Animals, Female, France epidemiology, Insect Vectors physiology, Polymerase Chain Reaction methods, Reoviridae Infections epidemiology, Reoviridae Infections transmission, Reoviridae Infections veterinary, Reoviridae Infections virology, Species Specificity, Ceratopogonidae physiology, Feeding Behavior physiology, Orbivirus physiology
- Abstract
Culicoides are small biting midges involved worldwide in the transmission of bluetongue and African horse sickness viruses. Feeding behaviours of Palaearctic biting midge species and their spatio-temporal dynamics remain unclear at the specific level. Three multiplex species-specific PCR-based assays were developed and used to identify blood meal source of engorged females of Palaearctic midge species of veterinary interest. Species-specific primers of potential hosts from livestock, domestic animals and wildlife (cattle, goat, sheep, red deer, roe deer, chamois, dog, pig, cat, horse) were designed and multiplexed from the mitochondrial cytochrome b gene. The assays also make possible to identify whether multiple blood meals have been taken. The first results from several Culicoides populations sampled in France highlight the utility of this valuable diagnostic tool combined with species identification assays, and suggest that most of the Culicoides species may have an opportunistic feeding behaviour regarding the host distribution and density. Noteworthy is the peculiar trophic behaviour of Culicoides chiopterus showing clear trends to cattle. Information on host preference and feeding behaviours are crucial for a better understanding of vector-host interactions and disease epidemiology., (Copyright © 2011 Elsevier B.V. All rights reserved.)
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- 2011
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44. Assessment of vector/host contact: comparison of animal-baited traps and UV-light/suction trap for collecting Culicoides biting midges (Diptera: Ceratopogonidae), vectors of Orbiviruses.
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Viennet E, Garros C, Lancelot R, Allène X, Gardès L, Rakotoarivony I, Crochet D, Delécolle JC, Moulia C, Baldet T, and Balenghien T
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- Animals, Female, France, Male, Sheep, Ultraviolet Rays, Ceratopogonidae physiology, Disease Vectors, Entomology methods, Feeding Behavior, Insect Bites and Stings
- Abstract
Background: The emergence and massive spread of bluetongue in Western Europe during 2006-2008 had disastrous consequences for sheep and cattle production and confirmed the ability of Palaearctic Culicoides (Diptera: Ceratopogonidae) to transmit the virus. Some aspects of Culicoides ecology, especially host-seeking and feeding behaviors, remain insufficiently described due to the difficulty of collecting them directly on a bait animal, the most reliable method to evaluate biting rates.Our aim was to compare typical animal-baited traps (drop trap and direct aspiration) to both a new sticky cover trap and a UV-light/suction trap (the most commonly used method to collect Culicoides)., Methods/results: Collections were made from 1.45 hours before sunset to 1.45 hours after sunset in June/July 2009 at an experimental sheep farm (INRA, Nouzilly, Western France), with 3 replicates of a 4 sites×4 traps randomized Latin square using one sheep per site. Collected Culicoides individuals were sorted morphologically to species, sex and physiological stages for females. Sibling species were identified using a molecular assay. A total of 534 Culicoides belonging to 17 species was collected. Abundance was maximal in the drop trap (232 females and 4 males from 10 species) whereas the diversity was the highest in the UV-light/suction trap (136 females and 5 males from 15 species). Significant between-trap differences abundance and parity rates were observed., Conclusions: Only the direct aspiration collected exclusively host-seeking females, despite a concern that human manipulation may influence estimation of the biting rate. The sticky cover trap assessed accurately the biting rate of abundant species even if it might act as an interception trap. The drop trap collected the highest abundance of Culicoides and may have caught individuals not attracted by sheep but by its structure. Finally, abundances obtained using the UV-light/suction trap did not estimate accurately Culicoides biting rate.
- Published
- 2011
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