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Allen SE, Vigil SL, Furukawa-Stoffer T, Colucci N, Ambagala A, Pearl DL, Ruder MG, Jardine CM, Nemeth NM. Abundance and diversity of Culicoides Latreille (Diptera: Ceratopogonidae) in southern Ontario, Canada. Parasit Vectors 2023; 16:201. [PMID: 37316934 DOI: 10.1186/s13071-023-05799-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 05/02/2023] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND Culicoides Latreille (Diptera: Ceratopogonidae) is a genus of hematophagous midges feeding on various vertebrate hosts and serving as a vector for numerous pathogens important to livestock and wildlife health. North American pathogens include bluetongue (BT) and epizootic hemorrhagic disease (EHD) viruses. Little is known about Culicoides spp. distribution and abundance and species composition in Ontario, Canada, despite bordering numerous U.S. states with documented Culicoides spp. and BT and EHD virus activity. We sought to characterize Culicoides spp. distribution and abundance and to investigate whether select meteorological and ecological risk factors influenced the abundance of Culicoides biguttatus, C. stellifer, and the subgenus Avaritia trapped throughout southern Ontario. METHODS From June to October of 2017 to 2018, CDC-type LED light suction traps were placed on twelve livestock-associated sites across southern Ontario. Culicoides spp. collected were morphologically identified to the species level when possible. Associations were examined using negative binomial regression among C. biguttatus, C. stellifer, and subgenus Avaritia abundance, and select factors: ambient temperature, rainfall, primary livestock species, latitude, and habitat type. RESULTS In total, 33,905 Culicoides spp. midges were collected, encompassing 14 species from seven subgenera and one species group. Culicoides sonorensis was collected from three sites during both years. Within Ontario, the northern trapping locations had a pattern of seasonal peak abundance in August (2017) and July (2018), and the southern locations had abundance peaks in June for both years. Culicoides biguttatus, C. stellifer, and subgenus Avaritia were significantly more abundant if ovine was the primary livestock species at trapping sites (compared to bovine). Culicoides stellifer and subgenus Avaritia were significantly more abundant at mid- to high-temperature ranges on trap days (i.e., 17.3-20.2 and 20.3-31.0 °C compared to 9.5-17.2 °C). Additionally, subgenus Avaritia were significantly more abundant if rainfall 4 weeks prior was between 2.7 and 20.1 mm compared to 0.0 mm and if rainfall 8 weeks prior was between 0.1 and 2.1 mm compared to 0.0 mm. CONCLUSIONS Results from our study describe Culicoides spp. distribution in southern Ontario, the potential for spread and maintenance of EHD and BT viruses, and concurrent health risks to livestock and wildlife in southern Ontario in reference to certain meteorological and ecological risk factors. We identified that Culicoides spp. are diverse in this province, and appear to be distinctly distributed spatially and temporally. The livestock species present, temperature, and rainfall appear to have an impact on the abundance of C. biguttatus, C. stellifer, and subgenus Avaritia trapped. These findings could help inform targeted surveillance, control measures, and the development of management guides for Culicoides spp. and EHD and BT viruses in southern Ontario, Canada.
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Affiliation(s)
- Samantha E Allen
- Wyoming Game and Fish Department, Veterinary Services, Laramie, USA.
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Canada.
- Canadian Wildlife Health Cooperative, Ontario Veterinary College, University of Guelph, Guelph, Canada.
| | - Stacey L Vigil
- Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, USA
| | - Tara Furukawa-Stoffer
- Canadian Food Inspection Agency, National Centre for Animal Diseases, Lethbridge, Canada
| | - Nicole Colucci
- Canadian Food Inspection Agency, National Centre for Animal Diseases, Lethbridge, Canada
| | - Aruna Ambagala
- Canadian Food Inspection Agency, National Centre for Foreign Animal Disease, Winnipeg, Canada
| | - David L Pearl
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, Canada
| | - Mark G Ruder
- Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, USA
| | - Claire M Jardine
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Canada
- Canadian Wildlife Health Cooperative, Ontario Veterinary College, University of Guelph, Guelph, Canada
| | - Nicole M Nemeth
- Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, USA
- Department of Pathology, University of Georgia, Athens, USA
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2
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Barceló C, Searle KR, Estrada R, Lucientes J, Miranda MÁ, Purse BV. The use of path analysis to determine effects of environmental factors on the adult seasonality of Culicoides (Diptera: Ceratopogonidae) vector species in Spain. BULLETIN OF ENTOMOLOGICAL RESEARCH 2023; 113:402-411. [PMID: 36908249 DOI: 10.1017/s0007485323000068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Culicoides biting midges (Diptera: Ceratopogonidae) are the main vectors of livestock diseases such as bluetongue (BT) which mainly affect sheep and cattle. In Spain, bluetongue virus (BTV) is transmitted by several Culicoides taxa, including Culicoides imicola, Obsoletus complex, Culicoides newsteadi and Culicoides pulicaris that vary in seasonality and distribution, affecting the distribution and dynamics of BT outbreaks. Path analysis is useful for separating direct and indirect, biotic and abiotic determinants of species' population performance and is ideal for understanding the sensitivity of adult Culicoides dynamics to multiple environmental drivers. Start, end of season and length of overwintering of adult Culicoides were analysed across 329 sites in Spain sampled from 2005 to 2010 during the National Entomosurveillance Program for BTV with path analysis, to determine the direct and indirect effects of land use, climate and host factor variables. Culicoides taxa had species-specific responses to environmental variables. While the seasonality of adult C. imicola was strongly affected by topography, temperature, cover of agro-forestry and sclerophyllous vegetation, rainfall, livestock density, photoperiod in autumn and the abundance of Culicoides females, Obsoletus complex species seasonality was affected by land-use variables such as cover of natural grassland and broad-leaved forest. Culicoides female abundance was the most explanatory variable for the seasonality of C. newsteadi, while C. pulicaris showed that temperature during winter and the photoperiod in November had a strong effect on the start of the season and the length of overwinter period of this species. These results indicate that the seasonal vector-free period (SVFP) in Spain will vary between competent vector taxa and geographic locations, dependent on the different responses of each taxa to environmental conditions.
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Affiliation(s)
- Carlos Barceló
- Applied Zoology and Animal Conservation Research Group, Department of Biology, University of the Balearic Islands (UIB), Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca, Spain
| | - Kate R Searle
- UK Centre for Ecology and Hydrology, Bush Estate, EH26 0QB Edinburgh, UK
| | - Rosa Estrada
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Javier Lucientes
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Miguel Á Miranda
- Applied Zoology and Animal Conservation Research Group, Department of Biology, University of the Balearic Islands (UIB), Ctra. Valldemossa Km 7.5, 07122 Palma de Mallorca, Spain
| | - Bethan V Purse
- UK Centre for Ecology and Hydrology, Oxfordshire OX10 8BB, UK
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3
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Stokes JE, Carpenter S, Sanders C, Gubbins S. Emergence dynamics of adult Culicoides biting midges at two farms in south-east England. Parasit Vectors 2022; 15:251. [PMID: 35820957 PMCID: PMC9277857 DOI: 10.1186/s13071-022-05370-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/01/2022] [Indexed: 11/24/2022] Open
Abstract
Background Culicoides biting midges (Diptera: Ceratopogonidae) are biological vectors of livestock arboviruses that cause diseases with significant economic, social and welfare impacts. Within temperate regions, livestock movement during arbovirus outbreaks can be facilitated by declaring a ‘seasonal vector-free period’ (SVFP) during winter when adult Culicoides are not active. In this study we carry out long-term monitoring of Culicoides adult emergence from larval development habitats at two farms in the UK to validate current definitions of the SVFP and to provide novel bionomic data for known vector species. Methods Standard emergence traps were used to collect emerging adult Culicoides from dung heaps at two cattle farms in the south-east of England from June to November 2016 and March 2017 to May 2018. Culicoides were morphologically identified to species or complex level and count data were analysed using a simple population dynamic model for pre-adult Culicoides that included meteorological components. Results More than 96,000 Culicoides were identified from 267 emergence trapping events across 2 years, revealing clear evidence of bivoltinism from peaks of male populations of Culicoidesobsoletus emerging from dung heaps. This pattern was also reflected in the emergence of adult female Obsoletus complex populations, which dominated the collections (64.4% of total catch) and emerged throughout the adult active period. Adult male C. obsoletus were observed emerging earlier than females (protandry) and emergence of both sexes occurred throughout the year. Culicoides chiopterus and Culicoides scoticus were also identified in spring emergence collections, providing the first evidence for the overwintering of larvae in dung heaps for these species. Conclusions This study demonstrates continual and highly variable rates of emergence of Culicoides throughout the year. A lack of evidence for mass emergence in spring along with the ability to observe male generations highlights the need for complementary surveillance techniques in addition to light-trap data when investigating seasonality and phenology. Evidence was found of other vector species, C. chiopterus and C. scoticus, utilising cattle dung heaps as an overwintering habitat, further highlighting the importance of these habitats on farms. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05370-z.
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Affiliation(s)
- Jessica Eleanor Stokes
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK. .,ProScience Ltd, Gloucestershire, GL11 5SD, UK.
| | - Simon Carpenter
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
| | | | - Simon Gubbins
- The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
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4
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Spatial epidemiology of hemorrhagic disease in Illinois wild white-tailed deer. Sci Rep 2022; 12:6888. [PMID: 35477968 PMCID: PMC9046210 DOI: 10.1038/s41598-022-10694-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 04/05/2022] [Indexed: 11/08/2022] Open
Abstract
Epizootic hemorrhagic disease (EHD) and bluetongue (BT) are vector-borne viral diseases that affect wild and domestic ruminants. Clinical signs of EHD and BT are similar; thus, the syndrome is referred to as hemorrhagic disease (HD). Syndromic surveillance and virus detection in North America reveal a northern expansion of HD. High mortalities at northern latitudes suggest recent incursions of HD viruses into northern geographic areas. We evaluated the occurrence of HD in wild Illinois white-tailed deer from 1982 to 2019. Our retrospective space-time analysis identified high-rate clusters of HD cases from 2006 to 2019. The pattern of northward expansion indicates changes in virus-host-vector interactions. Serological evidence from harvested deer revealed prior infection with BTV. However, BTV was not detected from virus isolation in dead deer sampled during outbreaks. Our findings suggest the value of capturing the precise geographic location of outbreaks, the importance of virus isolation to confirm the cause of an outbreak, and the importance of expanding HD surveillance to hunter-harvested wild white-tailed deer. Similarly, it assists in predicting future outbreaks, allowing for targeted disease and vector surveillance, helping wildlife agencies communicate with the public the cause of mortality events and viral hemorrhagic disease outcomes at local and regional scales.
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Rivera NA, Varga C, Ruder MG, Dorak SJ, Roca AL, Novakofski JE, Mateus-Pinilla NE. Bluetongue and Epizootic Hemorrhagic Disease in the United States of America at the Wildlife-Livestock Interface. Pathogens 2021; 10:915. [PMID: 34451380 PMCID: PMC8402076 DOI: 10.3390/pathogens10080915] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/18/2021] [Accepted: 07/19/2021] [Indexed: 11/17/2022] Open
Abstract
Bluetongue (BT) and epizootic hemorrhagic disease (EHD) cases have increased worldwide, causing significant economic loss to ruminant livestock production and detrimental effects to susceptible wildlife populations. In recent decades, hemorrhagic disease cases have been reported over expanding geographic areas in the United States. Effective BT and EHD prevention and control strategies for livestock and monitoring of these diseases in wildlife populations depend on an accurate understanding of the distribution of BT and EHD viruses in domestic and wild ruminants and their vectors, the Culicoides biting midges that transmit them. However, national maps showing the distribution of BT and EHD viruses and the presence of Culicoides vectors are incomplete or not available at all. Thus, efforts to accurately describe the potential risk of these viruses on ruminant populations are obstructed by the lack of systematic and routine surveillance of their hosts and vectors. In this review, we: (1) outline animal health impacts of BT and EHD in the USA; (2) describe current knowledge of the distribution and abundance of BT and EHD and their vectors in the USA; and (3) highlight the importance of disease (BT and EHD) and vector surveillance for ruminant populations.
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Affiliation(s)
- Nelda A. Rivera
- Illinois Natural History Survey-Prairie Research Institute, University of Illinois Urbana-Champaign, 1816 S. Oak Street, Champaign, IL 61820, USA; (S.J.D.); (J.E.N.)
| | - Csaba Varga
- Department of Pathobiology, University of Illinois Urbana-Champaign, 2001 S Lincoln Ave, Urbana, IL 61802, USA;
| | - Mark G. Ruder
- Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA;
| | - Sheena J. Dorak
- Illinois Natural History Survey-Prairie Research Institute, University of Illinois Urbana-Champaign, 1816 S. Oak Street, Champaign, IL 61820, USA; (S.J.D.); (J.E.N.)
| | - Alfred L. Roca
- Department of Animal Sciences, University of Illinois Urbana-Champaign, 1207 West Gregory Drive, Urbana, IL 61801, USA;
| | - Jan E. Novakofski
- Illinois Natural History Survey-Prairie Research Institute, University of Illinois Urbana-Champaign, 1816 S. Oak Street, Champaign, IL 61820, USA; (S.J.D.); (J.E.N.)
- Department of Animal Sciences, University of Illinois Urbana-Champaign, 1503 S. Maryland Drive, Urbana, IL 61801, USA
| | - Nohra E. Mateus-Pinilla
- Illinois Natural History Survey-Prairie Research Institute, University of Illinois Urbana-Champaign, 1816 S. Oak Street, Champaign, IL 61820, USA; (S.J.D.); (J.E.N.)
- Department of Pathobiology, University of Illinois Urbana-Champaign, 2001 S Lincoln Ave, Urbana, IL 61802, USA;
- Department of Animal Sciences, University of Illinois Urbana-Champaign, 1503 S. Maryland Drive, Urbana, IL 61801, USA
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6
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Möhlmann TWR, Keeling MJ, Wennergren U, Favia G, Santman-Berends I, Takken W, Koenraadt CJM, Brand SPC. Biting midge dynamics and bluetongue transmission: a multiscale model linking catch data with climate and disease outbreaks. Sci Rep 2021; 11:1892. [PMID: 33479304 PMCID: PMC7820592 DOI: 10.1038/s41598-021-81096-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 04/16/2020] [Indexed: 01/29/2023] Open
Abstract
Bluetongue virus (BTV) serotype 8 has been circulating in Europe since a major outbreak occurred in 2006, causing economic losses to livestock farms. The unpredictability of the biting activity of midges that transmit BTV implies difficulty in computing accurate transmission models. This study uniquely integrates field collections of midges at a range of European latitudes (in Sweden, The Netherlands, and Italy), with a multi-scale modelling approach. We inferred the environmental factors that influence the dynamics of midge catching, and then directly linked predicted midge catches to BTV transmission dynamics. Catch predictions were linked to the observed prevalence amongst sentinel cattle during the 2007 BTV outbreak in The Netherlands using a dynamic transmission model. We were able to directly infer a scaling parameter between daily midge catch predictions and the true biting rate per cow per day. Compared to biting rate per cow per day the scaling parameter was around 50% of 24 h midge catches with traps. Extending the estimated biting rate across Europe, for different seasons and years, indicated that whilst intensity of transmission is expected to vary widely from herd to herd, around 95% of naïve herds in western Europe have been at risk of sustained transmission over the last 15 years.
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Affiliation(s)
- Tim W R Möhlmann
- Laboratory of Entomology, Wageningen University and Research, P. O. Box 16, 1700 AA, Wageningen, The Netherlands
- IFM Theory and Modelling, Linköping University, 581 83, Linköping, Sweden
| | - Matt J Keeling
- School of Life Sciences, University of Warwick, Coventry, UK
- Zeeman Institute, University of Warwick, Coventry, UK
- Mathematics Institute, University of Warwick, Coventry, UK
| | - Uno Wennergren
- IFM Theory and Modelling, Linköping University, 581 83, Linköping, Sweden
| | - Guido Favia
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032, Camerino, Italy
| | | | - Willem Takken
- Laboratory of Entomology, Wageningen University and Research, P. O. Box 16, 1700 AA, Wageningen, The Netherlands
| | - Constantianus J M Koenraadt
- Laboratory of Entomology, Wageningen University and Research, P. O. Box 16, 1700 AA, Wageningen, The Netherlands
| | - Samuel P C Brand
- School of Life Sciences, University of Warwick, Coventry, UK.
- Zeeman Institute, University of Warwick, Coventry, UK.
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Barceló C, Purse BV, Estrada R, Lucientes J, Miranda MÁ, Searle KR. Environmental Drivers of Adult Seasonality and Abundance of Biting Midges Culicoides (Diptera: Ceratopogonidae), Bluetongue Vector Species in Spain. JOURNAL OF MEDICAL ENTOMOLOGY 2021; 58:350-364. [PMID: 32885822 DOI: 10.1093/jme/tjaa160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Indexed: 06/11/2023]
Abstract
Bluetongue is a viral disease affecting wild and domestic ruminants transmitted by several species of biting midges Culicoides Latreille. The phenology of these insects were analyzed in relation to potential environmental drivers. Data from 329 sites in Spain were analyzed using Bayesian Generalized Linear Mixed Model (GLMM) approaches. The effects of environmental factors on adult female seasonality were contrasted. Obsoletus complex species (Diptera: Ceratopogonidae) were the most prevalent across sites, followed by Culicoides newsteadi Austen (Diptera: Ceratopogonidae). Activity of female Obsoletus complex species was longest in sites at low elevation, with warmer spring average temperatures and precipitation, as well as in sites with high abundance of cattle. The length of the Culicoides imicola Kieffer (Diptera: Ceratopogonidae) female adult season was also longest in sites at low elevation with higher coverage of broad-leaved vegetation. Long adult seasons of C. newsteadi were found in sites with warmer autumns and higher precipitation, high abundance of sheep. Culicoides pulicaris (Linnaeus) (Diptera: Ceratopogonidae) had longer adult periods in sites with a greater number of accumulated degree days over 10°C during winter. These results demonstrate the eco-climatic and seasonal differences among these four taxa in Spain, which may contribute to determining sites with suitable environmental circumstances for each particular species to inform assessments of the risk of Bluetongue virus outbreaks in this region.
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Affiliation(s)
- Carlos Barceló
- Applied Zoology and Animal Conservation Research Group, Department of Biology, University of the Balearic Islands (UIB), Ctra. Valldemossa Km 7.5, Palma de Mallorca, Spain
| | - Bethan V Purse
- Centre for Ecology and Hydrology, Oxfordshire, United Kingdom
| | - Rosa Estrada
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Javier Lucientes
- Department of Animal Pathology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Miguel Á Miranda
- Applied Zoology and Animal Conservation Research Group, Department of Biology, University of the Balearic Islands (UIB), Ctra. Valldemossa Km 7.5, Palma de Mallorca, Spain
| | - Kate R Searle
- Centre for Ecology and Hydrology, Bush Estate, Edinburgh, Scotland
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Aguilar-Vega C, Bosch J, Fernández-Carrión E, Lucientes J, Sánchez-Vizcaíno JM. Identifying Spanish Areas at More Risk of Monthly BTV Transmission with a Basic Reproduction Number Approach. Viruses 2020; 12:E1158. [PMID: 33066209 PMCID: PMC7602074 DOI: 10.3390/v12101158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/08/2020] [Accepted: 10/12/2020] [Indexed: 01/24/2023] Open
Abstract
Bluetongue virus (BTV) causes a disease that is endemic in Spain and its two major biological vector species, C. imicola and the Obsoletus complex species, differ greatly in their ecology and distribution. Understanding the seasonality of BTV transmission in risk areas is key to improving surveillance and control programs, as well as to better understand the pathogen transmission networks between wildlife and livestock. Here, monthly risk transmission maps were generated using risk categories based on well-known BTV R0 equations and predicted abundances of the two most relevant vectors in Spain. Previously, Culicoides spp. predicted abundances in mainland Spain and the Balearic Islands were obtained using remote sensing data and random forest machine learning algorithm. Risk transmission maps were externally assessed with the estimated date of infection of BTV-1 and BTV-4 historical outbreaks. Our results highlight the differences in risk transmission during April-October, June-August being the period with higher R0 values. Likewise, a natural barrier has been identified between northern and central-southern areas at risk that may hamper BTV spread between them. Our results can be relevant to implement risk-based interventions for the prevention, control and surveillance of BTV and other diseases shared between livestock and wildlife host populations.
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Affiliation(s)
- Cecilia Aguilar-Vega
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
| | - Jaime Bosch
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
| | - Eduardo Fernández-Carrión
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
| | - Javier Lucientes
- Department of Animal Pathology (Animal Health), AgriFood Institute of Aragón IA2, Faculty of Veterinary Medicine, University of Zaragoza, 50013 Zaragoza, Spain;
| | - José Manuel Sánchez-Vizcaíno
- VISAVET Health Surveillance Centre, Animal Health Department, Faculty of Veterinary Medicine, Complutense University of Madrid, 28040 Madrid, Spain; (J.B.); (E.F.-C.); (J.M.S.-V.)
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Clark NJ, Drovetski SV, Voelker G. Robust geographical determinants of infection prevalence and a contrasting latitudinal diversity gradient for haemosporidian parasites in Western Palearctic birds. Mol Ecol 2020; 29:3131-3143. [PMID: 32652721 DOI: 10.1111/mec.15545] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/01/2020] [Accepted: 07/06/2020] [Indexed: 12/16/2022]
Abstract
Identifying robust environmental predictors of infection probability is central to forecasting and mitigating the ongoing impacts of climate change on vector-borne disease threats. We applied phylogenetic hierarchical models to a data set of 2,171 Western Palearctic individual birds from 47 species to determine how climate and landscape variation influence infection probability for three genera of haemosporidian blood parasites (Haemoproteus, Leucocytozoon, and Plasmodium). Our comparative models found compelling evidence that birds in areas with higher vegetation density (captured by the normalized difference vegetation index [NDVI]) had higher likelihoods of carrying parasite infection. Magnitudes of this relationship were remarkably similar across parasite genera considering that these parasites use different arthropod vectors and are widely presumed to be epidemiologically distinct. However, we also uncovered key differences among genera that highlighted complexities in their climate responses. In particular, prevalences of Haemoproteus and Plasmodium showed strong but contrasting relationships with winter temperatures, supporting mounting evidence that winter warming is a key environmental filter impacting the dynamics of host-parasite interactions. Parasite phylogenetic community diversities demonstrated a clear but contrasting latitudinal gradient, with Haemoproteus diversity increasing towards the equator and Leucocytozoon diversity increasing towards the poles. Haemoproteus diversity also increased in regions with higher vegetation density, supporting our evidence that summer vegetation density is important for structuring the distributions of these parasites. Ongoing variation in winter temperatures and vegetation characteristics will probably have far-reaching consequences for the transmission and spread of vector-borne diseases.
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Affiliation(s)
- Nicholas J Clark
- UQ Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Sergei V Drovetski
- US Geological Survey, Patuxent Wildlife Research Center, Beltsville, MD, USA
| | - Gary Voelker
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA
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Werner D, Groschupp S, Bauer C, Kampen H. Breeding Habitat Preferences of Major Culicoides Species (Diptera: Ceratopogonidae) in Germany. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17145000. [PMID: 32664561 PMCID: PMC7400431 DOI: 10.3390/ijerph17145000] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/01/2020] [Accepted: 07/06/2020] [Indexed: 01/14/2023]
Abstract
Biting midges of the genus Culicoides (Diptera, Ceratopognidae) are demonstrably or putatively involved in the transmission of both bluetongue (BTV) and Schmallenberg viruses (SBV) in Central Europe. Although these insects are ubiquitous in Europe, relatively little is known about their requirements in terms of breeding habitats and substrates. Culicoides species composition and relative abundance in potential breeding habitats were therefore studied at various locations in Northeastern Germany and one location in Western Germany by emergence trap collections. Forty-three potential breeding sites were analyzed in ten landscape structures, with 28,091 adult biting midges emerging from them. Among these, 2116 specimens belonged to the genus Culicoides. Species of the culicoid subgenus Avaritia were most abundant (70.6% of all specimens) and widespread (91.6% of all sites), while the subgenus Culicoides accounted for 15.6% of the specimens registered but emerged from 70.8% of all sites sampled. Culicoides species of other subgenera were collected in 75.0% of all studied sites, with a relative abundance of 8.7%. The results indicate that various types of dung, but probably also some landscape habitats, offer suitable substrates for the development of potential Culicoides vector species. Adaptations in dung management on farms and landscape design and use might therefore be appropriate approaches to reduce the risk of BTV or SBV transmission.
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Affiliation(s)
- Doreen Werner
- Research Area 2 “Land Use and Governance”, Leibniz Centre for Agricultural Landscape Research (ZALF), 15374 Müncheberg, Germany;
- Correspondence: ; Tel.: +49-33432-82-363
| | - Sarah Groschupp
- Research Area 2 “Land Use and Governance”, Leibniz Centre for Agricultural Landscape Research (ZALF), 15374 Müncheberg, Germany;
| | - Christian Bauer
- Working Group “Epidemiology”, Institute of Parasitology, Justus Liebig University, 35392 Giessen, Germany;
| | - Helge Kampen
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, 17493 Greifswald, Germany;
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11
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Lutz L, Verhoff MA, Amendt J. Environmental factors influencing flight activity of forensically important female blow flies in Central Europe. Int J Legal Med 2018; 133:1267-1278. [PMID: 30483869 DOI: 10.1007/s00414-018-1967-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/07/2018] [Indexed: 10/27/2022]
Abstract
In forensic entomology, evaluation of a possible delay between a person's death and insect colonization is crucial. We monitored the seasonal flight activities of the most abundant blow flies in an urban habitat in Frankfurt/Germany based on 152 sampling days between April and October 2017. Thirty-six thousand female specimens of 12 necrophagous taxa were sampled as a possible groundwork for establishing a prediction tool for the activity of certain forensically relevant taxa. The most abundant taxon was Lucilia sericata (n = 19,544), followed by Lucilia caesar (n = 8025), Calliphora vicina (n = 5224), and Lucilia ampullacea (n = 1834). Up to six environmental parameters were statistically significant predictors of fly presence, leading to unique patterns of seasonal and daily activity for all four species. In detail, our analysis proved that L. sericata is a sun-loving, high-summer species that dominates the warmer months and is mostly influenced by mean day temperature. In contrast, L. caesar seems to be a shade-loving species that dominates in autumn resp. late-season and is mainly influenced by mean day temperature and wind speed. The activity of L. ampullacea was highly related to mean day temperature and relative humidity. In contrast to all other species, C. vicina behaved differently, particularly due to its occurrence throughout the entire sampling interval and the higher tolerance limits for the measured abiotic parameters, especially temperature. The present study is groundwork for establishing a prediction tool for the flight and oviposition activity of forensically relevant taxa.
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Affiliation(s)
- Lena Lutz
- Institute of Legal Medicine, University Hospital Frankfurt am Main, Goethe-University, Kennedyallee 104, 60596, Frankfurt am Main, Germany.
| | - Marcel A Verhoff
- Institute of Legal Medicine, University Hospital Frankfurt am Main, Goethe-University, Kennedyallee 104, 60596, Frankfurt am Main, Germany
| | - Jens Amendt
- Institute of Legal Medicine, University Hospital Frankfurt am Main, Goethe-University, Kennedyallee 104, 60596, Frankfurt am Main, Germany
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12
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Jess S, Thompson GM, Clawson S, Forsythe IWN, Rea I, Gordon AW, Murchie AK. Surveillance of biting midges (Culicoides spp.) in Northern Ireland: influence of seasonality, surrounding habitat and livestock housing. MEDICAL AND VETERINARY ENTOMOLOGY 2018; 32:48-60. [PMID: 28842922 DOI: 10.1111/mve.12258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 05/30/2017] [Accepted: 06/21/2017] [Indexed: 06/07/2023]
Abstract
Biting midges, Culicoides spp. (Diptera: Ceratopogonidae), are important vectors of viral pathogens. Following the outbreak of bluetongue serotype 8 in Europe between 2006 and 2009, many Culicoides surveillance programmes were initiated to identify vector-active periods, in accordance with European Commission regulation 2007/1266/EC. This study utilized surveillance data from 4 years of continuous light-trapping at 14 sites in Northern Ireland. The number of captured Culicoides varied from none during the vector-free period (December-April) to more than 36 000 per night during peak activity in the summer. The Obsoletus group represented 75% of Culicoides collected and the Pulicaris group represented 21%. A total of 91% of Culicoides were female, of which 42% were parous. Abundance data, sex ratios and parous rates suggested that both the Obsoletus and Pulicaris groups underwent three generations/year. The Obsoletus group was associated with cattle-rearing habitats and woodland, the Impunctatus group was found in habitats related to sheep rearing and the Pulicaris group were associated with both cattle and sheep. Housing did not reduce incursion of female Obsoletus group Culicoides but it did for males and for the Pulicaris group Culicoides. The influence of housing was strongly affected by time of year, probably reflecting the presence of livestock indoors/outdoors.
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Affiliation(s)
- S Jess
- Sustainable Agri-Food Sciences Division, Agri-Food and Biosciences Institute, Belfast, Northern Ireland
| | - G M Thompson
- Sustainable Agri-Food Sciences Division, Agri-Food and Biosciences Institute, Belfast, Northern Ireland
- School of Biological Sciences, Queen's University of Belfast, Belfast, Northern Ireland
| | - S Clawson
- Sustainable Agri-Food Sciences Division, Agri-Food and Biosciences Institute, Belfast, Northern Ireland
| | - I W N Forsythe
- Sustainable Agri-Food Sciences Division, Agri-Food and Biosciences Institute, Belfast, Northern Ireland
| | - I Rea
- Sustainable Agri-Food Sciences Division, Agri-Food and Biosciences Institute, Belfast, Northern Ireland
| | - A W Gordon
- Finance and Corporate Affairs Division, Agri-Food and Biosciences Institute, Belfast, Northern Ireland
| | - A K Murchie
- Sustainable Agri-Food Sciences Division, Agri-Food and Biosciences Institute, Belfast, Northern Ireland
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13
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Cuéllar AC, Kjær LJ, Kirkeby C, Skovgard H, Nielsen SA, Stockmarr A, Andersson G, Lindstrom A, Chirico J, Lühken R, Steinke S, Kiel E, Gethmann J, Conraths FJ, Larska M, Hamnes I, Sviland S, Hopp P, Brugger K, Rubel F, Balenghien T, Garros C, Rakotoarivony I, Allène X, Lhoir J, Chavernac D, Delécolle JC, Mathieu B, Delécolle D, Setier-Rio ML, Venail R, Scheid B, Chueca MÁM, Barceló C, Lucientes J, Estrada R, Mathis A, Tack W, Bødker R. Spatial and temporal variation in the abundance of Culicoides biting midges (Diptera: Ceratopogonidae) in nine European countries. Parasit Vectors 2018; 11:112. [PMID: 29482593 PMCID: PMC5828119 DOI: 10.1186/s13071-018-2706-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/12/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are vectors of bluetongue virus (BTV), African horse sickness virus and Schmallenberg virus (SBV). Outbreaks of both BTV and SBV have affected large parts of Europe. The spread of these diseases depends largely on vector distribution and abundance. The aim of this analysis was to identify and quantify major spatial patterns and temporal trends in the distribution and seasonal variation of observed Culicoides abundance in nine countries in Europe. METHODS We gathered existing Culicoides data from Spain, France, Germany, Switzerland, Austria, Denmark, Sweden, Norway and Poland. In total, 31,429 Culicoides trap collections were available from 904 ruminant farms across these countries between 2007 and 2013. RESULTS The Obsoletus ensemble was distributed widely in Europe and accounted for 83% of all 8,842,998 Culicoides specimens in the dataset, with the highest mean monthly abundance recorded in France, Germany and southern Norway. The Pulicaris ensemble accounted for only 12% of the specimens and had a relatively southerly and easterly spatial distribution compared to the Obsoletus ensemble. Culicoides imicola Kieffer was only found in Spain and the southernmost part of France. There was a clear spatial trend in the accumulated annual abundance from southern to northern Europe, with the Obsoletus ensemble steadily increasing from 4000 per year in southern Europe to 500,000 in Scandinavia. The Pulicaris ensemble showed a very different pattern, with an increase in the accumulated annual abundance from 1600 in Spain, peaking at 41,000 in northern Germany and then decreasing again toward northern latitudes. For the two species ensembles and C. imicola, the season began between January and April, with later start dates and increasingly shorter vector seasons at more northerly latitudes. CONCLUSION We present the first maps of seasonal Culicoides abundance in large parts of Europe covering a gradient from southern Spain to northern Scandinavia. The identified temporal trends and spatial patterns are useful for planning the allocation of resources for international prevention and surveillance programmes in the European Union.
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Affiliation(s)
- Ana Carolina Cuéllar
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark.
| | - Lene Jung Kjær
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark
| | - Carsten Kirkeby
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark
| | - Henrik Skovgard
- Department of Agroecology - Entomology and Plant Pathology, Aarhus University, Aarhus, Denmark
| | - Søren Achim Nielsen
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Anders Stockmarr
- Department of Applied Mathematics and Computer Science, Technical University of Denmark (DTU), Copenhagen, Denmark
| | | | | | - Jan Chirico
- National Veterinary Institute (SVA), Uppsala, Sweden
| | - Renke Lühken
- Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research National Reference Centre for Tropical Infectious Diseases, Hamburg, Germany
| | - Sonja Steinke
- Department of Biology and Environmental Sciences, Carl von Ossietzky University, Oldenburg, Germany
| | - Ellen Kiel
- Department of Biology and Environmental Sciences, Carl von Ossietzky University, Oldenburg, Germany
| | - Jörn Gethmann
- Institute of Epidemiology, Friedrich Loeffler Institute, Greifswald, Germany
| | - Franz J Conraths
- Institute of Epidemiology, Friedrich Loeffler Institute, Greifswald, Germany
| | - Magdalena Larska
- Department of Virology, National Veterinary Research Institute, Pulawy, Poland
| | | | | | - Petter Hopp
- Norwegian Veterinary Institute, Oslo, Norway
| | | | - Franz Rubel
- Institute for Veterinary Public Health, Vetmeduni, Vienna, Austria
| | | | | | | | | | | | | | - Jean-Claude Delécolle
- Institute of Parasitology and Tropical Pathology of Strasbourg, EA7292, Université de Strasbourg, Strasbourg, France
| | - Bruno Mathieu
- Institute of Parasitology and Tropical Pathology of Strasbourg, EA7292, Université de Strasbourg, Strasbourg, France
| | - Delphine Delécolle
- Institute of Parasitology and Tropical Pathology of Strasbourg, EA7292, Université de Strasbourg, Strasbourg, France
| | | | - Roger Venail
- EID Méditerranée, Montpellier, France
- Avia-GIS NV, Zoersel, Belgium
| | | | | | - Carlos Barceló
- Laboratory of Zoology, University of the Balearic Islands, Palma de Mallorca, Spain
| | - Javier Lucientes
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - Rosa Estrada
- Department of Animal Pathology, University of Zaragoza, Zaragoza, Spain
| | - Alexander Mathis
- Institute of Parasitology, University of Zürich, Zürich, Switzerland
| | | | - Rene Bødker
- Division for Diagnostics and Scientific Advice, National Veterinary Institute, Technical University of Denmark (DTU), Copenhagen, Denmark
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14
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Brand SPC, Keeling MJ. The impact of temperature changes on vector-borne disease transmission: Culicoides midges and bluetongue virus. J R Soc Interface 2017; 14:rsif.2016.0481. [PMID: 28298609 DOI: 10.1098/rsif.2016.0481] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 02/20/2017] [Indexed: 11/12/2022] Open
Abstract
It is a long recognized fact that climatic variations, especially temperature, affect the life history of biting insects. This is particularly important when considering vector-borne diseases, especially in temperate regions where climatic fluctuations are large. In general, it has been found that most biological processes occur at a faster rate at higher temperatures, although not all processes change in the same manner. This differential response to temperature, often considered as a trade-off between onward transmission and vector life expectancy, leads to the total transmission potential of an infected vector being maximized at intermediate temperatures. Here we go beyond the concept of a static optimal temperature, and mathematically model how realistic temperature variation impacts transmission dynamics. We use bluetongue virus (BTV), under UK temperatures and transmitted by Culicoides midges, as a well-studied example where temperature fluctuations play a major role. We first consider an optimal temperature profile that maximizes transmission, and show that this is characterized by a warm day to maximize biting followed by cooler weather to maximize vector life expectancy. This understanding can then be related to recorded representative temperature patterns for England, the UK region which has experienced BTV cases, allowing us to infer historical transmissibility of BTV, as well as using forecasts of climate change to predict future transmissibility. Our results show that when BTV first invaded northern Europe in 2006 the cumulative transmission intensity was higher than any point in the last 50 years, although with climate change such high risks are the expected norm by 2050. Such predictions would indicate that regular BTV epizootics should be expected in the UK in the future.
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Affiliation(s)
- Samuel P C Brand
- Zeeman Institute: SBIDER, University of Warwick, Coventry CV4 7AL, UK .,School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Matt J Keeling
- Zeeman Institute: SBIDER, University of Warwick, Coventry CV4 7AL, UK.,School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK.,Mathematics Institute, University of Warwick, Coventry CV4 7AL, UK
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15
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White SM, Sanders CJ, Shortall CR, Purse BV. Mechanistic model for predicting the seasonal abundance of Culicoides biting midges and the impacts of insecticide control. Parasit Vectors 2017; 10:162. [PMID: 28347327 PMCID: PMC5369195 DOI: 10.1186/s13071-017-2097-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 03/20/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding seasonal patterns of abundance of insect vectors is important for optimisation of control strategies of vector-borne diseases. Environmental drivers such as temperature, humidity and photoperiod influence vector abundance, but it is not generally known how these drivers combine to affect seasonal population dynamics. METHODS In this paper, we derive and analyse a novel mechanistic stage-structured simulation model for Culicoides biting midges-the principle vectors of bluetongue and Schmallenberg viruses which cause mortality and morbidity in livestock and impact trade. We model variable life-history traits as functional forms that are dependent on environmental drivers, including air temperature, soil temperature and photoperiod. The model is fitted to Obsoletus group adult suction-trap data sampled daily at five locations throughout the UK for 2008. RESULTS The model predicts population dynamics that closely resemble UK field observations, including the characteristic biannual peaks of adult abundance. Using the model, we then investigate the effects of insecticide control, showing that control strategies focussing on the autumn peak of adult midge abundance have the highest impact in terms of population reduction in the autumn and averaged over the year. Conversely, control during the spring peak of adult abundance leads to adverse increases in adult abundance in the autumn peak. CONCLUSIONS The mechanisms of the biannual peaks of adult abundance, which are important features of midge seasonality in northern Europe and are key determinants of the risk of establishment and spread of midge-borne diseases, have been hypothesised over for many years. Our model suggests that the peaks correspond to two generations per year (bivoltine) are largely determined by pre-adult development. Furthermore, control strategies should focus on reducing the autumn peak since the immature stages are released from density-dependence regulation. We conclude that more extensive modelling of Culicoides biting midge populations in different geographical contexts will help to optimise control strategies and predictions of disease outbreaks.
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Affiliation(s)
- Steven M White
- Centre for Ecology & Hydrology, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK. .,Wolfson Centre for Mathematical Biology, Mathematical Institute, Radcliffe Observatory Quarter, Woodstock Road, Oxford, Oxfordshire, OX2 6GG, UK.
| | | | | | - Bethan V Purse
- Centre for Ecology & Hydrology, Benson Lane, Wallingford, Oxfordshire, OX10 8BB, UK
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16
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Abstract
The performance of different bluetongue control measures related to both vaccination and protection from bluetongue virus (BTV) vectors was assessed. By means of a mathematical model, it was concluded that when vaccination is applied on 95% of animals even for 3 years, bluetongue cannot be eradicated and is able to re‐emerge. Only after 5 years of vaccination, the infection may be close to the eradication levels. In the absence of vaccination, the disease can persist for several years, reaching an endemic condition with low level of prevalence of infection. Among the mechanisms for bluetongue persistence, the persistence in the wildlife, the transplacental transmission in the host, the duration of viraemia and the possible vertical transmission in vectors were assessed. The criteria of the current surveillance scheme in place in the EU for demonstration of the virus absence need revision, because it was highlighted that under the current surveillance policy bluetongue circulation might occur undetected. For the safe movement of animals, newborn ruminants from vaccinated mothers with neutralising antibodies can be considered protected against infection, although a protective titre threshold cannot be identified. The presence of colostral antibodies interferes with the vaccine immunisation in the newborn for more than 3 months after birth, whereas the minimum time after vaccination of animal to be considered immune can be up to 48 days. The knowledge about vectors ecology, mechanisms of over‐wintering and criteria for the seasonally vector‐free period was updated. Some Culicoides species are active throughout the year and an absolute vector‐free period may not exist at least in some areas in Europe. To date, there is no evidence that the use of insecticides and repellents reduce the transmission of BTV in the field, although this may reduce host/vector contact. By only using pour‐on insecticides, protection of animals is lower than the one provided by vector‐proof establishments. This publication is linked to the following EFSA Supporting Publications article: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1182/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.EN-1171/full
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17
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Sanders CJ, Harrup LE, Tugwell LA, Brugman VA, England M, Carpenter S. Quantification of within- and between-farm dispersal of Culicoides biting midges using an immunomarking technique. J Appl Ecol 2017; 54:1429-1439. [PMID: 29104309 PMCID: PMC5655569 DOI: 10.1111/1365-2664.12875] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/24/2017] [Indexed: 01/01/2023]
Abstract
Culicoides biting midges (Diptera, Ceratopogonidae) are vectors of arboviruses that cause significant economic and welfare impact. Local‐scale spread of Culicoides‐borne arboviruses is largely determined by the between‐farm movement of infected Culicoides. Study of the dispersal behaviour of Culicoides by capture–mark–recapture (CMR) is problematic due to the likelihood of mortality and changes in behaviour upon capture caused by the small size and fragility of these insects, evidenced by low recapture rates. To counter the problem of using CMR with Culicoides, this study utilised an ovalbumin immunomarking technique to quantify the within‐ and between‐farm dispersal of Culicoides in southern England. Both within‐ and between‐farm dispersal of Culicoides was observed. Of the 9058 Culicoides collected over 22 nights of trapping, 600 ovalbumin‐positive Culicoides, of 12 species including those implicated as arbovirus vectors, were collected with a maximum dispersal distance of 3125 m. This study provides the first species‐level data on the between‐farm dispersal of potential bluetongue, Schmallenberg and African horse sickness virus vectors in northern Europe. High‐resolution meteorological data determined upwind and downwind flight by Culicoides had occurred. Cumulative collection and meteorological data suggest 15·6% of flights over 1 km were upwind of the treatment area and 84·4% downwind. Synthesis and applications. The use of immunomarking eliminates the potential adverse effects on survival and behaviour of insect collection prior to marking, substantially improving the resolution and accuracy of estimates of the dispersal potential of small and delicate vector species such as Culicoides. Using this technique, quantification of the range of Culicoides dispersal with regard to meteorological conditions including wind direction will enable improved, data‐driven modelling of the spread of Culicoides‐borne arboviruses and will inform policy response to incursions and outbreaks.
The use of immunomarking eliminates the potential adverse effects on survival and behaviour of insect collection prior to marking, substantially improving the resolution and accuracy of estimates of the dispersal potential of small and delicate vector species such as Culicoides. Using this technique, quantification of the range of Culicoides dispersal with regard to meteorological conditions including wind direction will enable improved, data‐driven modelling of the spread of Culicoides‐borne arboviruses and will inform policy response to incursions and outbreaks.
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Affiliation(s)
| | - Lara E Harrup
- The Pirbright Institute Ash Road Pirbright Surrey GU24 0NF UK
| | - Laura A Tugwell
- The Pirbright Institute Ash Road Pirbright Surrey GU24 0NF UK
| | | | - Marion England
- The Pirbright Institute Ash Road Pirbright Surrey GU24 0NF UK
| | - Simon Carpenter
- The Pirbright Institute Ash Road Pirbright Surrey GU24 0NF UK
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18
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Versteirt V, Balenghien T, Tack W, Wint W. A first estimation of Culicoides imicola and Culicoides obsoletus/Culicoides scoticus seasonality and abundance in Europe. ACTA ACUST UNITED AC 2017. [DOI: 10.2903/sp.efsa.2017.en-1182] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - T Balenghien
- Institut Agronomique et Vétérinaire Hassan II Madinat Al Irfane Morocco
| | | | - W Wint
- Environmental Research Group Oxford The United Kingdom
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19
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Bessell PR, Searle KR, Auty HK, Handel IG, Purse BV, Bronsvoort BMDC. Assessing the potential for Bluetongue virus 8 to spread and vaccination strategies in Scotland. Sci Rep 2016; 6:38940. [PMID: 27958339 PMCID: PMC5154200 DOI: 10.1038/srep38940] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 11/16/2016] [Indexed: 12/11/2022] Open
Abstract
Europe has seen frequent outbreaks of Bluetongue (BT) disease since 2006, including an outbreak of BT virus serotype 8 in central France during 2015 that has continued to spread in Europe during 2016. Thus, assessing the potential for BTv-8 spread and determining the optimal deployment of vaccination is critical for contingency planning. We developed a spatially explicit mathematical model of BTv-8 spread in Scotland and explored the sensitivity of transmission to key disease spread parameters for which detailed empirical data is lacking. With parameters at mean values, there is little spread of BTv-8 in Scotland. However, under a “worst case” but still feasible scenario with parameters at the limits of their ranges and temperatures 1 °C warmer than the mean, we find extensive spread with 203,000 sheep infected given virus introduction to the south of Scotland between mid-May and mid-June. Strategically targeted vaccine interventions can greatly reduce BT spread. Specifically, despite BT having most clinical impact in sheep, we show that vaccination can have the greatest impact on reducing BTv infections in sheep when administered to cattle, which has implications for disease control policy.
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Affiliation(s)
- Paul R Bessell
- The Roslin Institute, The University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - Kate R Searle
- Centre for Ecology and Hydrology, Edinburgh, EH26 0QB, UK
| | - Harriet K Auty
- Epidemiology Research Unit, Future Farming Systems Group, Scotland's Rural College (SRUC), An Lòchran, Inverness Campus, Inverness, IV2 5NA, UK
| | - Ian G Handel
- Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - Bethan V Purse
- Centre for Ecology and Hydrology, Wallingford, OX10 8BB, UK
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20
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Stevenson TJ, Visser ME, Arnold W, Barrett P, Biello S, Dawson A, Denlinger DL, Dominoni D, Ebling FJ, Elton S, Evans N, Ferguson HM, Foster RG, Hau M, Haydon DT, Hazlerigg DG, Heideman P, Hopcraft JGC, Jonsson NN, Kronfeld-Schor N, Kumar V, Lincoln GA, MacLeod R, Martin SAM, Martinez-Bakker M, Nelson RJ, Reed T, Robinson JE, Rock D, Schwartz WJ, Steffan-Dewenter I, Tauber E, Thackeray SJ, Umstatter C, Yoshimura T, Helm B. Disrupted seasonal biology impacts health, food security and ecosystems. Proc Biol Sci 2016; 282:20151453. [PMID: 26468242 PMCID: PMC4633868 DOI: 10.1098/rspb.2015.1453] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The rhythm of life on earth is shaped by seasonal changes in the environment. Plants and animals show profound annual cycles in physiology, health, morphology, behaviour and demography in response to environmental cues. Seasonal biology impacts ecosystems and agriculture, with consequences for humans and biodiversity. Human populations show robust annual rhythms in health and well-being, and the birth month can have lasting effects that persist throughout life. This review emphasizes the need for a better understanding of seasonal biology against the backdrop of its rapidly progressing disruption through climate change, human lifestyles and other anthropogenic impact. Climate change is modifying annual rhythms to which numerous organisms have adapted, with potential consequences for industries relating to health, ecosystems and food security. Disconcertingly, human lifestyles under artificial conditions of eternal summer provide the most extreme example for disconnect from natural seasons, making humans vulnerable to increased morbidity and mortality. In this review, we introduce scenarios of seasonal disruption, highlight key aspects of seasonal biology and summarize from biomedical, anthropological, veterinary, agricultural and environmental perspectives the recent evidence for seasonal desynchronization between environmental factors and internal rhythms. Because annual rhythms are pervasive across biological systems, they provide a common framework for trans-disciplinary research.
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Affiliation(s)
- T J Stevenson
- Institute for Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - M E Visser
- Department of Animal Ecology, Nederlands Instituut voor Ecologie, Wageningen, The Netherlands
| | - W Arnold
- Research Institute of Wildlife Ecology, University of Vienna, Vienna, Austria
| | - P Barrett
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - S Biello
- School of Psychology, University of Glasgow, Glasgow, UK
| | - A Dawson
- Centre for Ecology and Hydrology, Penicuik, Midlothian, UK
| | - D L Denlinger
- Department of Entomology, Ohio State University, Columbus, OH, USA
| | - D Dominoni
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - F J Ebling
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - S Elton
- Department of Anthropology, Durham University, Durham, UK
| | - N Evans
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - H M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - R G Foster
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - M Hau
- Max Planck Institute for Ornithology, Seewiesen, Germany
| | - D T Haydon
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - D G Hazlerigg
- Department of Arctic and Marine Biology, University of Tromso, Tromso, Norway
| | - P Heideman
- Department of Biology, The College of William and Mary, Williamsburg, VA, USA
| | - J G C Hopcraft
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - N N Jonsson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | | | - V Kumar
- Department of Zoology, University of Delhi, Delhi, India
| | - G A Lincoln
- School of Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - R MacLeod
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - S A M Martin
- Department of Animal Ecology, Nederlands Instituut voor Ecologie, Wageningen, The Netherlands
| | - M Martinez-Bakker
- Department of Ecology and Evolution, University of Michigan, Ann Arbor, MI, USA
| | - R J Nelson
- Department of Psychology, Ohio State University, Columbus, OH, USA
| | - T Reed
- Aquaculture and Fisheries Development Centre, University of College Cork, Cork, Ireland
| | - J E Robinson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - D Rock
- School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Australia
| | - W J Schwartz
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - I Steffan-Dewenter
- Department of Animal Ecology and Tropical Biology, University of Wuerzburg, Wuerzburg, Germany
| | - E Tauber
- Department of Genetics, University of Leicester, Leicester, UK
| | - S J Thackeray
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - C Umstatter
- Agroscope, Tanikon, CH-8356 Ettenhausen, Switzerland
| | - T Yoshimura
- Department of Applied Molecular Biosciences, University of Nagoya, Nagoya, Japan
| | - B Helm
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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Foxi C, Delrio G, Falchi G, Marche MG, Satta G, Ruiu L. Role of different Culicoides vectors (Diptera: Ceratopogonidae) in bluetongue virus transmission and overwintering in Sardinia (Italy). Parasit Vectors 2016; 9:440. [PMID: 27502924 PMCID: PMC4977893 DOI: 10.1186/s13071-016-1733-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 07/28/2016] [Indexed: 11/25/2022] Open
Abstract
Background Bluetongue (BT) epidemics have affected the Mediterranean island of Sardinia since 2000. While Culicoides imicola represents the main bluetongue virus (BTV) vector, other European Culicoides biting midges, possibly implicated in virus transmission, have been detected here. Understanding their distribution, seasonal abundance, and infection rates is necessary to predict disease incidence and spread across coastal and inland areas, and to define their role in virus overwintering. Methods Biting midge abundance was determined by light traps on selected farms representing diverse climatic conditions of Sardinia. Livestock-associated Culicoides species were morphologically and molecularly identified. Infection rates in prevailing midge species captured in 2013 during a BTV-1 outbreak were determined using RT-qPCR based virus detection in insect body pools, supplemented by specific body region analyses. The seasonal infection prevalence in Culicoides samples collected in 2001 in a BTV-2 affected farm was also determined. Results The Newsteadi complex (C. newsteadi species A and species B) prevailed among all biting midge species (47.7 %), followed by C. imicola (27.8 %) and the Obsoletus complex (C. obsoletus and C. scoticus) (17.6 %). Whilst Culicoides imicola was more abundant along the coast, the Newsteadi complex was frequently collected at higher altitude and the Obsoletus complex was notably associated to cattle farms. Culicoides pulicaris and C. punctatus abundance was found to be marginal in all farms. BTV was detected in parous female samples of all these species, and the full dissemination of the virus within the body of C. imicola, C. obsoletus, C. scoticus, and Newsteadi complex species was confirmed by analyses of thorax and head, containing salivary glands. Higher infection rates were associated with C. scoticus, C. newsteadi species A and species B, compared to C. imicola. The virus was detected in C. newsteadi species A and C. obsoletus in winter and spring, whereas it was mainly found in summer and autumn in C. imicola. Conclusions In Sardinia, bluetongue virus is transmitted by multiple Culicoides vectors, including C. imicola and the Newsteadi complex being the most important. The Newsteadi complex and other midge species can play an important role in internal areas and are likely to be directly involved in virus overwintering.
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Affiliation(s)
- Cipriano Foxi
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy
| | - Gavino Delrio
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy
| | - Giovanni Falchi
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy
| | | | - Giuseppe Satta
- Istituto Zooprofilattico Sperimentale della Sardegna, Via Duca degli Abruzzi 8, Sassari, Italy
| | - Luca Ruiu
- Dipartimento di Agraria, University of Sassari, Via E. De Nicola, Sassari, Italy.
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Lühken R, Steinke S, Hoppe N, Kiel E. Effects of temperature and photoperiod on the development of overwintering immature Culicoides chiopterus and C. dewulfi. Vet Parasitol 2015; 214:195-9. [DOI: 10.1016/j.vetpar.2015.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 09/03/2015] [Accepted: 10/01/2015] [Indexed: 10/22/2022]
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Environmental drivers of Culicoides phenology: how important is species-specific variation when determining disease policy? PLoS One 2014; 9:e111876. [PMID: 25386940 PMCID: PMC4227682 DOI: 10.1371/journal.pone.0111876] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/18/2014] [Indexed: 11/19/2022] Open
Abstract
Since 2006, arboviruses transmitted by Culicoides biting midges (Diptera: Ceratopogonidae) have caused significant disruption to ruminant production in northern Europe. The most serious incursions involved strains of bluetongue virus (BTV), which cause bluetongue (BT) disease. To control spread of BTV, movement of susceptible livestock is restricted with economic and animal welfare impacts. The timing of BTV transmission in temperate regions is partly determined by the seasonal presence of adult Culicoides females. Legislative measures therefore allow for the relaxation of ruminant movement restrictions during winter, when nightly light-suction trap catches of Culicoides fall below a threshold (the ‘seasonally vector free period’: SVFP). We analysed five years of time-series surveillance data from light-suction trapping in the UK to investigate whether significant inter-specific and yearly variation in adult phenology exists, and whether the SVFP is predictable from environmental factors. Because female vector Culicoides are not easily morphologically separated, inter-specific comparisons in phenology were drawn from male populations. We demonstrate significant inter-specific differences in Culicoides adult phenology with the season of Culicoides scoticus approximately eight weeks shorter than Culicoides obsoletus. Species-specific differences in the length of the SVFP were related to host density and local variation in landscape habitat. When the Avaritia Culicoides females were modelled as a group (as utilised in the SFVP), we were unable to detect links between environmental drivers and phenological metrics. We conclude that the current treatment of Avaritia Culicoides as a single group inhibits understanding of environmentally-driven spatial variation in species phenology and hinders the development of models for predicting the SVFP from environmental factors. Culicoides surveillance methods should be adapted to focus on concentrated assessments of species-specific abundance during the start and end of seasonal activity in temperate regions to facilitate refinement of ruminant movement restrictions thereby reducing the impact of Culicoides-borne arboviruses.
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Impact of temperature, feeding preference and vaccination on Schmallenberg virus transmission in Scotland. Sci Rep 2014; 4:5746. [PMID: 25034464 PMCID: PMC4102919 DOI: 10.1038/srep05746] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 07/01/2014] [Indexed: 11/17/2022] Open
Abstract
First identified in 2011, Schmallenberg virus (SBV) is principally transmitted by Culicoides midges and affects ruminants. Clinical presentation is typified by foetal abnormalities, but despite very high infection rates, relatively few animals present with clinical signs. In this paper we further develop a previously published stochastic mathematical model of SBV spread to investigate the optimal deployment of a vaccine for SBV in Scotland, a country that has experienced only sporadic and isolated cases of SBV. We consider the use of the vaccine under different temperatures and explore the effects of a vector preference for feeding on cattle. We demonstrate that vaccine impact is optimised by targeting it at the high risk areas in the south of Scotland, or vaccinating only cattle. At higher than average temperatures, and hence increased transmission potential, the relative impact of vaccination is considerably enhanced. Vaccine impact is also enhanced if vectors feed preferentially on cattle. These findings are of considerable importance when planning control strategies for SBV and also have important implications for management of other arboviruses such as Bluetongue virus. Environmental determinants and feeding preferences should be researched further to inform development of effective control strategies.
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Kirkeby C, Bødker R, Stockmarr A, Lind P. Spatial abundance and clustering of Culicoides (Diptera: Ceratopogonidae) on a local scale. Parasit Vectors 2013; 6:43. [PMID: 23433251 PMCID: PMC3608001 DOI: 10.1186/1756-3305-6-43] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 01/24/2013] [Indexed: 11/21/2022] Open
Abstract
Background Biting midges, Culicoides, of the Obsoletus group and the Pulicaris group have been involved in recent outbreaks of bluetongue virus and the former was also involved in the Schmallenberg virus outbreak in northern Europe. Methods For the first time, here we investigate the local abundance pattern of these two species groups in the field by intensive sampling with a grid of light traps on 16 catch nights. Neighboring trap catches can be spatially dependent on each other, hence we developed a conditional autoregressive (CAR) model framework to test a number of spatial and non-spatial covariates expected to affect Culicoides abundance. Results The distance to sheep penned in the corner of the study field significantly increased the abundance level up to 200 meters away from the sheep. Spatial clustering was found to be significant but could not be explained by any known factors, and cluster locations shifted between catch nights. No significant temporal autocorrelation was detected. CAR models for both species groups identified a significant positive impact of humidity and significant negative impacts of precipitation and wind turbulence. Temperature was also found to be significant with a peak at just below 16 degrees Celcius. Surprisingly, there was a significant positive impact of wind speed. The CAR model for the Pulicaris group also identified a significant attraction to the smaller groups of sheep placed in the field. Furthermore, a large number of spatial covariates which were incorrectly found to be significant in ordinary regression models were not significant in the CAR models. The 95% C.I. on the prediction estimates ranged from 20.4% to 304.8%, underlining the difficulties of predicting the abundance of Culicoides. Conclusions We found that significant spatial clusters of Culicoides moved around in a dynamic pattern varying between catch nights. This conforms with the modeling but was not explained by any of the tested covariates. The mean abundance within these clusters was up to 11 times higher for the Obsoletus group and 4 times higher for the Pulicaris group compared to the rest of the field.
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Affiliation(s)
- Carsten Kirkeby
- National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, Frederiksberg C, DK-1870, Denmark.
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Bessell PR, Searle KR, Auty HK, Handel IG, Purse BV, Bronsvoort BMD. Epidemic potential of an emerging vector borne disease in a marginal environment: Schmallenberg in Scotland. Sci Rep 2013; 3:1178. [PMID: 23378911 PMCID: PMC3560360 DOI: 10.1038/srep01178] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 01/11/2013] [Indexed: 12/22/2022] Open
Abstract
During 2011 Schmallenberg virus (SBV) presented as a novel disease of cattle and sheep that had apparently spread through northern Europe over a relatively short period of time, but has yet to infect Scotland. This paper describes the development of a model of SBV spread applied to Scotland in the event of an incursion. This model shows that SBV spread is very sensitive to the temperature, with relatively little spread and few reproductive losses predicted in years with average temperatures but extensive spread (>1 million animals infected) and substantial reproductive losses in the hottest years. These results indicate that it is possible for SBV to spread in Scotland, however spread is limited by climatic conditions and the timing of introduction. Further results show that the transmission kernel shape and extrinsic incubation period parameter have a non-linear effect on disease transmission, so a greater understanding of the SBV transmission parameters is required.
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Affiliation(s)
- Paul R Bessell
- The Roslin Institute, The University of Edinburgh, Easter Bush, EH25 9RG.
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Rigot T, Conte A, Goffredo M, Ducheyne E, Hendrickx G, Gilbert M. Predicting the spatio-temporal distribution of Culicoides imicola in Sardinia using a discrete-time population model. Parasit Vectors 2012; 5:270. [PMID: 23174043 PMCID: PMC3561275 DOI: 10.1186/1756-3305-5-270] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 11/09/2012] [Indexed: 11/13/2022] Open
Abstract
Background Culicoides imicola KIEFFER, 1913 (Diptera: Ceratopogonidae) is the principal vector of Bluetongue disease in the Mediterranean basin, Africa and Asia. Previous studies have identified a range of eco-climatic variables associated with the distribution of C. imicola, and these relationships have been used to predict the large-scale distribution of the vector. However, these studies are not temporally-explicit and can not be used to predict the seasonality in C. imicola abundances. Between 2001 and 2006, longitudinal entomological surveillance was carried out throughout Italy, and provided a comprehensive spatio-temporal dataset of C. imicola catches in Onderstepoort-type black-light traps, in particular in Sardinia where the species is considered endemic. Methods We built a dynamic model that allows describing the effect of eco-climatic indicators on the monthly abundances of C. imicola in Sardinia. Model precision and accuracy were evaluated according to the influence of process and observation errors. Results A first-order autoregressive cofactor, a digital elevation model and MODIS Land Surface Temperature (LST)/or temperatures acquired from weather stations explained ~77% of the variability encountered in the samplings carried out in 9 sites during 6 years. Incorporating Normalized Difference Vegetation Index (NDVI) or rainfall did not increase the model's predictive capacity. On average, dynamics simulations showed good accuracy (predicted vs. observed r corr = 0.9). Although the model did not always reproduce the absolute levels of monthly abundances peaks, it succeeded in reproducing the seasonality in population level and allowed identifying the periods of low abundances and with no apparent activity. On that basis, we mapped C. imicola monthly distribution over the entire Sardinian region. Conclusions This study demonstrated prospects for modelling data arising from Culicoides longitudinal entomological surveillance. The framework explicitly incorporates the influence of eco-climatic factors on population growth rates and accounts for observation and process errors. Upon validation, such a model could be used to predict monthly population abundances on the basis of environmental conditions, and hence can potentially reduce the amount of entomological surveillance.
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Affiliation(s)
- Thibaud Rigot
- Biological control and spatial ecology LUBIES, Université Libre de Bruxelles, Av F,D, Roosevelt 50, Brussels, B-1050, Belgium.
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