{"title":"Winter activity of Culicoides (Diptera: Ceratopogonidae) inside and outside stables in Germany","authors":"Sarah Groschupp, Helge Kampen, Doreen Werner","doi":"10.1111/mve.12756","DOIUrl":null,"url":null,"abstract":"<p><i>Culicoides</i> biting midge species (Diptera: Ceratopogonidae) of the Obsoletus Group and the Pulicaris Complex are considered the major vectors of bluetongue and Schmallenberg viruses in Europe. Overwintering strategies of these arboviruses are controversially discussed, with the ongoing activity of vector species and a non-disrupted transmission cycle during winter being a plausible explanation. Although data on <i>Culicoides</i> winter activity are relatively scant, a seasonal vector-free period (SVFP), during which adult <i>Culicoides</i> are not or hardly active, is questionable. To determine winter activity and define SVFPs according to the EU Commission Regulation No 1266/2007, adult <i>Culicoides</i> were trapped weekly with UV-light traps from October to April 2019/2020 and 2020/2021 inside and outside stables on 16 farms throughout Germany. Temperature measurements were taken regularly at each trapping site since the temperature is a known driver of biting midge activity. In 960 indoor and outdoor catches, 32,377 <i>Culicoides</i> were trapped, with 90.9% of them belonging to the Obsoletus Group, 6.1% to the Pulicaris Complex and 3.0% to ‘other <i>Culicoides</i>’ according to morphological identification. The majority (61.3%) of <i>Culicoides</i> were trapped indoors, with substantial numbers of specimens collected from October to December, in March and in April, and only a few or no specimens in January and February. Obsoletus Group biting midges were active indoors for almost the entire winter. Outdoors, <i>Culicoides</i> numbers decreased from October to December, few or no specimens were caught from January to March, and high numbers were captured in April. Of the collected <i>Culicoides</i>, 2028 were blood-fed, of which 94.6% were trapped in the stables. The indoor SVFP, although calculated for blood-fed instead of parous females, lasted for almost 4 months (late November until mid-March) in winter 2019/2020 and 2 months (January and February) in winter 2020/2021. The outdoor SVFPs covered almost the entire study period in both winters, with slight differences between the onsets and the ends. The <i>Culicoides</i> activity significantly depended on temperature. Specimens of the Obsoletus Group were caught at an average temperature of 7.4°C (minimum 0.3°C) and of the Pulicaris Complex at an average temperature of 10.3°C (minimum 1.2°C). These temperatures were reached inside the stables over more extended periods than outside. The average indoor temperatures were 1.2 K higher than the average outdoor temperatures, although absolute temperature differences of up to 9.0 K were recorded. Based on <i>Culicoides</i> activity, the results of the present study indicate an almost continuous potential for virus transmission in winter within livestock houses.</p>","PeriodicalId":18350,"journal":{"name":"Medical and Veterinary Entomology","volume":"38 4","pages":"552-565"},"PeriodicalIF":1.6000,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/mve.12756","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Medical and Veterinary Entomology","FirstCategoryId":"97","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/mve.12756","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENTOMOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Culicoides biting midge species (Diptera: Ceratopogonidae) of the Obsoletus Group and the Pulicaris Complex are considered the major vectors of bluetongue and Schmallenberg viruses in Europe. Overwintering strategies of these arboviruses are controversially discussed, with the ongoing activity of vector species and a non-disrupted transmission cycle during winter being a plausible explanation. Although data on Culicoides winter activity are relatively scant, a seasonal vector-free period (SVFP), during which adult Culicoides are not or hardly active, is questionable. To determine winter activity and define SVFPs according to the EU Commission Regulation No 1266/2007, adult Culicoides were trapped weekly with UV-light traps from October to April 2019/2020 and 2020/2021 inside and outside stables on 16 farms throughout Germany. Temperature measurements were taken regularly at each trapping site since the temperature is a known driver of biting midge activity. In 960 indoor and outdoor catches, 32,377 Culicoides were trapped, with 90.9% of them belonging to the Obsoletus Group, 6.1% to the Pulicaris Complex and 3.0% to ‘other Culicoides’ according to morphological identification. The majority (61.3%) of Culicoides were trapped indoors, with substantial numbers of specimens collected from October to December, in March and in April, and only a few or no specimens in January and February. Obsoletus Group biting midges were active indoors for almost the entire winter. Outdoors, Culicoides numbers decreased from October to December, few or no specimens were caught from January to March, and high numbers were captured in April. Of the collected Culicoides, 2028 were blood-fed, of which 94.6% were trapped in the stables. The indoor SVFP, although calculated for blood-fed instead of parous females, lasted for almost 4 months (late November until mid-March) in winter 2019/2020 and 2 months (January and February) in winter 2020/2021. The outdoor SVFPs covered almost the entire study period in both winters, with slight differences between the onsets and the ends. The Culicoides activity significantly depended on temperature. Specimens of the Obsoletus Group were caught at an average temperature of 7.4°C (minimum 0.3°C) and of the Pulicaris Complex at an average temperature of 10.3°C (minimum 1.2°C). These temperatures were reached inside the stables over more extended periods than outside. The average indoor temperatures were 1.2 K higher than the average outdoor temperatures, although absolute temperature differences of up to 9.0 K were recorded. Based on Culicoides activity, the results of the present study indicate an almost continuous potential for virus transmission in winter within livestock houses.
期刊介绍:
Medical and Veterinary Entomology is the leading periodical in its field. The Journal covers the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. The main strengths of the Journal lie in the fields of:
-epidemiology and transmission of vector-borne pathogens
changes in vector distribution that have impact on the pathogen transmission-
arthropod behaviour and ecology-
novel, field evaluated, approaches to biological and chemical control methods-
host arthropod interactions.
Please note that we do not consider submissions in forensic entomology.