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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, Garros C. DNA barcoding and molecular identification of field-collected Culicoides larvae in the Niayes area of Senegal. Parasit Vectors 2018; 11:615. [PMID: 30509304 PMCID: PMC6276223 DOI: 10.1186/s13071-018-3176-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/28/2018] [Indexed: 12/26/2022] Open
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. Electronic supplementary material The online version of this article (10.1186/s13071-018-3176-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mame Thierno Bakhoum
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l'Elevage et de Recherches Vétérinaires, BP 2057, Dakar, Sénégal. .,CIRAD, UMR ASTRE, F-34398, Montpellier, France. .,ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France.
| | - Mamadou Sarr
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l'Elevage et de Recherches Vétérinaires, BP 2057, Dakar, Sénégal
| | - Assane Gueye Fall
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l'Elevage et de Recherches Vétérinaires, BP 2057, Dakar, Sénégal
| | - Karine Huber
- ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France
| | - Moussa Fall
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l'Elevage et de Recherches Vétérinaires, BP 2057, Dakar, Sénégal
| | - Mbacké Sembène
- Département de Biologie Animale, Université Cheikh Anta Diop de Dakar, Dakar, Sénégal
| | - Momar Talla Seck
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l'Elevage et de Recherches Vétérinaires, BP 2057, Dakar, Sénégal
| | - Karien Labuschagne
- Agricultural Research Council-Onderstepoort Veterinary Research, Epidemiology, Parasites and Vectors, Onderstepoort, ZA-0110, South Africa.,Department of Zoology and Entomology, University of Pretoria, Pretoria, ZA-0002, South Africa
| | - Laetitia Gardès
- CIRAD, UMR ASTRE, F-34398, Montpellier, France.,ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France
| | - Mamadou Ciss
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l'Elevage et de Recherches Vétérinaires, BP 2057, Dakar, Sénégal
| | - Geoffrey Gimonneau
- CIRAD, UMR INTERTRYP, F-34398, Montpellier, France.,Centre International de Recherche - Développement sur l'Elevage en zone subhumide, Bobo-Dioulasso 01, BP 454, Burkina Faso
| | - Jérémy Bouyer
- CIRAD, UMR ASTRE, F-34398, Montpellier, France.,ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France
| | - Thierry Baldet
- CIRAD, UMR ASTRE, F-34398, Montpellier, France.,ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France
| | - Claire Garros
- ASTRE, Univ Montpellier, CIRAD, INRA, Montpellier, France.,CIRAD, UMR ASTRE, Sainte Clotilde, F- 97491, Réunion, France
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Ramilo DW, Nunes T, Madeira S, Boinas F, da Fonseca IP. Geographical distribution of Culicoides (DIPTERA: CERATOPOGONIDAE) in mainland Portugal: Presence/absence modelling of vector and potential vector species. PLoS One 2017; 12:e0180606. [PMID: 28683145 PMCID: PMC5500329 DOI: 10.1371/journal.pone.0180606] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 06/19/2017] [Indexed: 12/24/2022] Open
Abstract
Vector-borne diseases are not only accounted responsible for their burden on human health-care systems, but also known to cause economic constraints to livestock and animal production. Animals are affected directly by the transmitted pathogens and indirectly when animal movement is restricted. Distribution of such diseases depends on climatic and social factors, namely, environmental changes, globalization, trade and unplanned urbanization. Culicoides biting midges are responsible for the transmission of several pathogenic agents with relevant economic impact. Due to a fragmentary knowledge of their ecology, occurrence is difficult to predict consequently, limiting the control of these arthropod vectors. In order to understand the distribution of Culicoides species, in mainland Portugal, data collected during the National Entomologic Surveillance Program for Bluetongue disease (2005-2013), were used for statistical evaluation. Logistic regression analysis was preformed and prediction maps (per season) were obtained for vector and potentially vector species. The variables used at the present study were selected from WorldClim (two climatic variables) and CORINE databases (twenty-two land cover variables). This work points to an opposite distribution of C. imicola and species from the Obsoletus group within mainland Portugal. Such findings are evidenced in autumn, with the former appearing in Central and Southern regions. Although appearing northwards, on summer and autumn, C. newsteadi reveals a similar distribution to C. imicola. The species C. punctatus appears in all Portuguese territory throughout the year. Contrary, C. pulicaris is poorly caught in all areas of mainland Portugal, being paradoxical present near coastal areas and higher altitude regions.
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Affiliation(s)
- David W. Ramilo
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
| | - Telmo Nunes
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
| | - Sara Madeira
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
| | - Fernando Boinas
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
| | - Isabel Pereira da Fonseca
- Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- * E-mail:
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Carpenter S, Mellor PS, Fall AG, Garros C, Venter GJ. African Horse Sickness Virus: History, Transmission, and Current Status. ANNUAL REVIEW OF ENTOMOLOGY 2017; 62:343-358. [PMID: 28141961 DOI: 10.1146/annurev-ento-031616-035010] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
African horse sickness virus (AHSV) is a lethal arbovirus of equids that is transmitted between hosts primarily by biting midges of the genus Culicoides (Diptera: Ceratopogonidae). AHSV affects draft, thoroughbred, and companion horses and donkeys in Africa, Asia, and Europe. In this review, we examine the impact of AHSV critically and discuss entomological studies that have been conducted to improve understanding of its epidemiology and control. The transmission of AHSV remains a major research focus and we critically review studies that have implicated both Culicoides and other blood-feeding arthropods in this process. We explore AHSV both as an epidemic pathogen and within its endemic range as a barrier to development, an area of interest that has been underrepresented in studies of the virus to date. By discussing AHSV transmission in the African republics of South Africa and Senegal, we provide a more balanced view of the virus as a threat to equids in a diverse range of settings, thus leading to a discussion of key areas in which our knowledge of transmission could be improved. The use of entomological data to detect, predict and control AHSV is also examined, including reference to existing studies carried out during unprecedented outbreaks of bluetongue virus in Europe, an arbovirus of wild and domestic ruminants also transmitted by Culicoides.
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Affiliation(s)
- Simon Carpenter
- Vector-borne Viral Diseases Program, Pirbright Institute, Woking, Surrey GU24 0NF, United Kingdom;
| | - Philip S Mellor
- Vector-borne Viral Diseases Program, Pirbright Institute, Woking, Surrey GU24 0NF, United Kingdom;
| | | | - Claire Garros
- Cirad UMR15 CMAEE, 34398 Montpellier, Cedex 5, France
| | - Gert J Venter
- Parasites, Vectors, and Vector-Borne Diseases, Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria 0001, South Africa
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Bakhoum MT, Fall AG, Fall M, Bassene CK, Baldet T, Seck MT, Bouyer J, Garros C, Gimonneau G. Insight on the larval habitat of Afrotropical Culicoides Latreille (Diptera: Ceratopogonidae) in the Niayes area of Senegal, West Africa. Parasit Vectors 2016; 9:462. [PMID: 27549191 PMCID: PMC4994380 DOI: 10.1186/s13071-016-1749-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/11/2016] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Certain biting midges species of the genus Culicoides (Diptera: Ceratopogonidae) are vectors of virus to livestock worldwide. Culicoides larval ecology has remained overlooked because of difficulties to identify breeding sites, methodological constraints to collect samples and lack of morphological tools to identify field-collected individuals to the species level. After the 2007 unforeseen outbreaks of African horse sickness virus (AHSV) in Senegal (West Africa), there is a need to identify suitable and productive larval habitats in horse farms for the main Culicoides species to evaluate the implementation of vector control measures or preventive actions. METHODS We investigate twelve putative larval habitats (habitat types) of Culicoides inside and outside of three horse farms in the Niayes area of Senegal using a combination of flotation and emergence methods during four collection sessions. RESULTS Among the three studied horse farms, three habitat types were found positive for Culicoides larvae: pond edge, lake edge and puddle edge. A total of 1420 Culicoides individuals (519♂/901♀) belonging to ten species emerged from the substrate samples. Culicoides oxystoma (40 %), C. similis (25 %) and C. nivosus (24 %) were the most abundant species and emerged from the three habitat types while C. kingi (5 %) was only retrieved from lake edges and one male emerged from puddle edge. Culicoides imicola (1.7 %) was found in low numbers and retrieved only from pond and puddle edges. CONCLUSIONS Larval habitats identified were not species-specific. All positive larval habitats were found outside the horse farms. This study provides original baseline information on larval habitats of Culicoides species in Senegal in an area endemic for AHSV, in particular for species of interest in animal health. These data will serve as a point of reference for future investigations on larval ecology and larval control measures.
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Affiliation(s)
- Mame T. Bakhoum
- Cirad, UMR CMAEE, Montpellier, France
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, BP 2057, Dakar-Hann, Sénégal
| | - Assane G. Fall
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, BP 2057, Dakar-Hann, Sénégal
| | - Moussa Fall
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, BP 2057, Dakar-Hann, Sénégal
| | - Chiavaroli K. Bassene
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, BP 2057, Dakar-Hann, Sénégal
| | | | - Momar T. Seck
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, BP 2057, Dakar-Hann, Sénégal
| | - Jérémy Bouyer
- Cirad, UMR CMAEE, Montpellier, France
- PATTEC coordination office, P. O. Box 3243, Addis Ababa, Ethiopia
| | | | - Geoffrey Gimonneau
- Cirad, UMR CMAEE, Montpellier, France
- Institut Sénégalais de Recherches Agricoles, Laboratoire National de l’Elevage et de Recherches Vétérinaires, BP 2057, Dakar-Hann, Sénégal
- Cirad, UMR INTERTRYP, F-34398, Montpellier, France
- Present address: CIRDES, BP454, Bobo-Dioulasso, Burkina Faso
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5
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Harrup LE, Laban S, Purse BV, Reddy YK, Reddy YN, Byregowda SM, Kumar N, Purushotham KM, Kowalli S, Prasad M, Prasad G, Bettis AA, De Keyser R, Logan J, Garros C, Gopurenko D, Bellis G, Labuschagne K, Mathieu B, Carpenter S. DNA barcoding and surveillance sampling strategies for Culicoides biting midges (Diptera: Ceratopogonidae) in southern India. Parasit Vectors 2016; 9:461. [PMID: 27549137 PMCID: PMC4994320 DOI: 10.1186/s13071-016-1722-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 07/25/2016] [Indexed: 11/10/2022] Open
Abstract
Background Culicoides spp. biting midges transmit bluetongue virus (BTV), the aetiological agent of bluetongue (BT), an economically important disease of ruminants. In southern India, hyperendemic outbreaks of BT exert high cost to subsistence farmers in the region, impacting on sheep production. Effective Culicoides spp. monitoring methods coupled with accurate species identification can accelerate responses for minimising BT outbreaks. Here, we assessed the utility of sampling methods and DNA barcoding for detection and identification of Culicoides spp. in southern India, in order to provide an informed basis for future monitoring of their populations in the region. Methods Culicoides spp. collected from Tamil Nadu and Karnataka were used to construct a framework for future morphological identification in surveillance, based on sequence comparison of the DNA barcode region of the mitochondrial cytochrome c oxidase I (COI) gene and achieving quality standards defined by the Barcode of Life initiative. Pairwise catches of Culicoides spp. were compared in diversity and abundance between green (570 nm) and ultraviolet (UV) (390 nm) light emitting diode (LED) suction traps at a single site in Chennai, Tamil Nadu over 20 nights of sampling in November 2013. Results DNA barcode sequences of Culicoides spp. were mostly congruent both with existing DNA barcode data from other countries and with morphological identification of major vector species. However, sequence differences symptomatic of cryptic species diversity were present in some groups which require further investigation. While the diversity of species collected by the UV LED Center for Disease Control (CDC) trap did not significantly vary from that collected by the green LED CDC trap, the UV CDC significantly outperformed the green LED CDC trap with regard to the number of Culicoides individuals collected. Conclusions Morphological identification of the majority of potential vector species of Culicoides spp. samples within southern India appears relatively robust; however, potential cryptic species diversity was present in some groups requiring further investigation. The UV LED CDC trap is recommended for surveillance of Culicoides in southern India. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1722-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lara E Harrup
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Woking, Surrey, GU24 0NF, UK.
| | - Swathi Laban
- Vaccine Research Centre-Viral Vaccines, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, 600 051, India
| | - Bethan V Purse
- Centre for Ecology and Hydrology, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, UK
| | - Yarabolu Krishnamohan Reddy
- Vaccine Research Centre-Viral Vaccines, Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Madhavaram Milk Colony, Chennai, 600 051, India
| | - Yella Narasimha Reddy
- Department of Veterinary Microbiology, College of Veterinary Science, Rajendranagar, Hyderabad, 500030, Andhra Pradesh, India
| | | | - Naveen Kumar
- Institute of Animal Health and Veterinary Biologicals, Hebbal, 560024, Bengaluru, India
| | | | - Shrikant Kowalli
- Institute of Animal Health and Veterinary Biologicals, Hebbal, 560024, Bengaluru, India
| | - Minakshi Prasad
- Department of Animal Biotechnology, Lala Lajpat Rai University of Veterinary and Animal Sciences, College of Veterinary Science, Hisar, 125004, Haryana, India
| | - Gaya Prasad
- Department of Animal Biotechnology, Lala Lajpat Rai University of Veterinary and Animal Sciences, College of Veterinary Science, Hisar, 125004, Haryana, India.,Indian Council Agricultural Research, New Delhi, 110 001, India
| | - Alison A Bettis
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Rien De Keyser
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - James Logan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Claire Garros
- Cirad, UMR15 CMAEE, F-34398, Montpellier, France.,INRA, UMR1309 CMAEE, F-34398, Montpellier, France
| | - David Gopurenko
- NSW Department of Primary Industries, PMB, Wagga Wagga Agricultural Institute, Wagga Wagga, NSW, 2650, Australia.,Graham Centre for Agricultural Innovation, Locked Bag 588, Wagga Wagga, NSW, 2678, Australia
| | - Glenn Bellis
- Department of Agriculture, Fisheries and Forestry, Winnellie, Australia
| | - Karien Labuschagne
- Onderstepoort Veterinary Institute, Agricultural Research Council-Onderstepoort Veterinary Institute, PVVD, ZA-0110, Onderstepoort, South Africa.,Department of Zoology and Entomology, University of Pretoria, ZA-0002, Pretoria, South Africa
| | - Bruno Mathieu
- Institut de Parasitologie et de Pathologie tropicale de Strasbourg (IPPTS), EA7292, Faculté de Médecine, 3 rue Koeberlé, F-67000, Strasbourg, France
| | - Simon Carpenter
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Woking, Surrey, GU24 0NF, UK
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Steinke S, Lühken R, Balczun C, Kiel E. Emergence of Culicoides obsoletus group species from farm-associated habitats in Germany. MEDICAL AND VETERINARY ENTOMOLOGY 2016; 30:174-184. [PMID: 26744290 DOI: 10.1111/mve.12159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/30/2015] [Accepted: 10/31/2015] [Indexed: 06/05/2023]
Abstract
Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) may transmit several arboviruses to ruminant livestock. The species of the Obsoletus group are considered to be among the most important vectors of bluetongue virus (BTV) in northern Europe. As agricultural environments offer suitable habitats for the development of their immature stages, the emergence of adult Culicoides from potential breeding sites was investigated at 20 cattle farms throughout Germany in 2012 and 2013. In analyses of species-specific habitat preferences and relationships between Culicoides abundance in breeding substrates and their physicochemical characteristics, dungheaps emerged as the most important substrate for the development of Culicoides obsoletus sensu stricto (s.s.) (Meigen), whereas Culicoides chiopterus (Meigen) and Culicoides dewulfi Goetghebuer were generally restricted to cowpats. A decreasing pH value was associated with a higher abundance or a higher probability of observing these three species. Furthermore, the abundance of C. obsoletus s.s. was positively related to increasing moisture. Dungheaps were very productive breeding sites for this species and are therefore suggested as a target for potential control measures.
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Affiliation(s)
- S Steinke
- Research Group for Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | - R Lühken
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany
| | - C Balczun
- Laboratory of Medical Parasitology, Central Institute of the Bundeswehr Medical Service, Koblenz, Germany
| | - E Kiel
- Research Group for Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
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Impact of experimental flooding on larvae and pupae of dung-breeding Culicoides. Parasitol Res 2016; 115:3825-30. [PMID: 27234035 DOI: 10.1007/s00436-016-5144-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/19/2016] [Indexed: 10/21/2022]
Abstract
Culicoides biting midges (Diptera: Ceratopogonidae) spend the greatest part of their life in the larval stage. However, knowledge on the immature stages and the impact of abiotic factors on their development is still poor. Therefore, we investigated the effect of flooding on the larvae and pupae of Culicoides chiopterus (Meigen, 1830) and C. dewulfi Goetghebuer, 1936. In water, the larvae of both species showed head-to-tail flexions and sinuous flexions, at slow rates, but were not able to swim. Flooding of larvae for 24 h did not affect the number of emerging adults; flooding of pupae significantly reduced the emergence rate of C. chiopterus, compared to the control group, while C. dewulfi was not affected. Pupae were not able to float and no pupae survived flooding for 10 days. After flooding of larvae for 10 days, 50 % of C. chiopterus and 4 % of C. dewulfi completed the pre-adult development. During this treatment, 84 % of C. chiopterus and 48 % of C. dewulfi larvae pupated in water.
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Delineation of the population genetic structure of Culicoides imicola in East and South Africa. Parasit Vectors 2015; 8:660. [PMID: 26704134 PMCID: PMC4690384 DOI: 10.1186/s13071-015-1277-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 12/19/2015] [Indexed: 11/10/2022] Open
Abstract
Background Culicoides imicola Kieffer, 1913 is the main vector of bluetongue virus (BTV) and African horse sickness virus (AHSV) in Sub-Saharan Africa. Understanding the population genetic structure of this midge and the nature of barriers to gene flow will lead to a deeper understanding of bluetongue epidemiology and more effective vector control in this region. Methods A panel of 12 DNA microsatellite markers isolated de novo and mitochondrial DNA were utilized in a study of C. imicola populations from Africa and an outlier population from the Balearic Islands. The DNA microsatellite markers and mitochondrial DNA were also used to examine a population of closely related C. bolitinos Meiswinkel midges. Results The microsatellite data suggest gene flow between Kenya and south-west Indian Ocean Islands exist while a restricted gene flow between Kenya and South Africa C. imicola populations occurs. Genetic distance correlated with geographic distance by Mantel test. The mitochondrial DNA analysis results imply that the C. imicola populations from Kenya and south-west Indian Ocean Islands (Madagascar and Mauritius) shared haplotypes while C. imicola population from South Africa possessed private haplotypes and the highest nucleotide diversity among the African populations. The Bayesian skyline plot suggested a population growth. Conclusions The gene flow demonstrated by this study indicates a potential risk of introduction of new BTV serotypes by wind-borne infected Culicoides into the Islands. Genetic similarity between Mauritius and South Africa may be due to translocation as a result of human-induced activities; this could impact negatively on the livestock industry. The microsatellite markers isolated in this study may be utilised to study C. bolitinos, an important vector of BTV and AHSV in Africa and identify sources of future incursions. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1277-4) contains supplementary material, which is available to authorized users.
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Harrup LE, Bellis GA, Balenghien T, Garros C. Culicoides Latreille (Diptera: Ceratopogonidae) taxonomy: current challenges and future directions. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2015; 30:249-266. [PMID: 25535946 PMCID: PMC4330985 DOI: 10.1016/j.meegid.2014.12.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/12/2014] [Accepted: 12/13/2014] [Indexed: 11/23/2022]
Abstract
Culicoides Latreille biting midges (Diptera: Ceratopogonidae) cause a significant biting nuisance to humans, livestock and equines, and are the biological vectors of a range of internationally important pathogens of both veterinary and medical importance. Despite their economic significance, the delimitation and identification of species and evolutionary relationships between species within this genus remains at best problematic. To date no phylogenetic study has attempted to validate the subgeneric classification of the genus and the monophyly of many of the subgenera remains doubtful. Many informal species groupings are also known to exist but few are adequately described, further complicating accurate identification. Recent contributions to Culicoides taxonomy at the species level have revealed a high correlation between morphological and molecular analyses although molecular analyses are revealing the existence of cryptic species. This review considers the methods for studying the systematics of Culicoides using both morphological and genetic techniques, with a view to understanding the factors limiting our current understanding of Culicoides biology and hence arbovirus epidemiology. In addition, we examine the global status of Culicoides identification, highlighting areas that are poorly addressed, including the potential implementation of emerging technologies.
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Affiliation(s)
- L E Harrup
- Vector-borne Viral Diseases Programme, The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK.
| | - G A Bellis
- University of Queensland, St Lucia, Brisbane, Qld, Australia
| | - T Balenghien
- Cirad, UMR15 CMAEE, 34398 Montpellier, France; INRA, UMR1309 CMAEE, 34398 Montpellier, France
| | - C Garros
- Cirad, UMR15 CMAEE, 34398 Montpellier, France; INRA, UMR1309 CMAEE, 34398 Montpellier, France
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Lühken R, Kiel E, Steinke S, Fladung R. Topsoil conditions correlate with the emergence rates of Culicoides chiopterus and Culicoides dewulfi (Diptera: Ceratopogonidae) from cowpats. Parasitol Res 2015; 114:1113-7. [PMID: 25563611 DOI: 10.1007/s00436-014-4284-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 12/23/2014] [Indexed: 10/24/2022]
Abstract
Culicoides chiopterus (Meigen), 1830 and Culicoides dewulfi Goetghebuer, 1936 (Diptera: Ceratopogonidae) are considered to develop exclusively in dung, but do not necessarily show an equal distribution and abundance on livestock farms in Northern Europe. Recent modelling studies identified soil parameters to explain these differences. The present study addressed the question whether topsoil conditions underneath cowpats correlate with the number of emerging C. chiopterus and C. dewulfi. We recorded the emergence of biting midges from 24 cowpats over a period of 4 weeks and analysed samples from the topsoil. In agreement with species distribution models based on remote data, our results detected the correlation of soil moisture, organic matter and soil texture with the number of emerging C. chiopterus and C. dewulfi. With increasing soil moisture, the number of emerging adults increased for both species and the amount of organic matter was positively correlated with the number of emerging C. chiopterus. In contrast, soil textures showed conflicting results, i.e. a positive and negative relationship with the same variables. According to our results, soil underneath dung can explain the number of emerging Culicoides species. The knowledge of these effects might improve the interpretation of large-scaled distribution models for dung-breeding biting midges.
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Affiliation(s)
- Renke Lühken
- Research Group Aquatic Ecology and Nature Conservation, Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111, Oldenburg, Germany,
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Lühken R, Steinke S, Wittmann A, Kiel E. Impact of flooding on the immature stages of dung-breeding Culicoides in Northern Europe. Vet Parasitol 2014; 205:289-94. [PMID: 24986464 DOI: 10.1016/j.vetpar.2014.06.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 06/01/2014] [Accepted: 06/10/2014] [Indexed: 11/29/2022]
Abstract
In Northern Europe, dung-breeding Culicoides (e.g., Culicoides chiopterus (Meigen 1830) and Culicoides dewulfi (Goetghebuer 1936)) are considered to be important vectors of the Bluetongue virus and Schmallenberg virus. The interpretation of their distribution is difficult due to the lack of knowledge about their ecology. Previously, soil moisture and especially flooding were identified as important factors that influence the development of several biting-midge species. Therefore, this experimental study addressed the question whether flooding has a negative impact on the development of immature stages of Obsoletus group species. Ten cowpats were collected, and each was divided into four quarters and kept at different moisture regimes in a greenhouse: (1) "dry" (no water added), (2) "control" (regularly moistened), (3) "alternately flooded" and (4) "permanently flooded", to compare Culicoides emergence. Flooding had a significant negative impact on the emergence of Culicoides. No individuals emerged from the "permanently flooded" treatment and only two individuals were sampled from the "alternately flooded" treatment. In contrast, the total emergence from the non-flooded samples in the "dry" (96 individuals, 38.6% of all Culicoides) and "control" (151 individuals, 60.6% of all biting midges) treatments was considerably higher. Biting midges were predominantly identified as C. dewulfi (161 individuals, 64.7% of all Culicoides) and C. chiopterus (63 individuals, 25.3% of all Culicoides). There were no significant differences in emergence between the "dry" and "control" treatments. Our results highlight the importance of soil moisture on the distribution of C. chiopterus and C. dewulfi. Regarding physiological and behavioural adaptations of other Culicoides species, we argue that pupae of C. chiopterus and C. dewulfi are in danger of drowning when breeding sites are flooded as they cannot float. On the contrary, our results indicate that desiccation might not be harmful to these species.
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Affiliation(s)
- Renke Lühken
- Research Group Aquatic Ecology and Nature Conservation, Institute of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany.
| | - Sonja Steinke
- Research Group Aquatic Ecology and Nature Conservation, Institute of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany
| | - Anna Wittmann
- Research Group Aquatic Ecology and Nature Conservation, Institute of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany
| | - Ellen Kiel
- Research Group Aquatic Ecology and Nature Conservation, Institute of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstraße 114-118, 26111 Oldenburg, Germany
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