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Background: After several years without bluetongue disease, a ruminant illness caused by Culicoides-borne bluetongue virus (BTV), two new autochthonous cases were reported in 2018 in Germany. By contrast, Schmallenberg virus (SBV), another Culicoides-borne virus pathogenic to ruminants, has continuously circulated in Germany since its first emergence in 2011. The disease outbreaks have triggered numerous studies on the biology of the Culicoides vectors, but many ecological details are still obscure. Methods: Culicoides biting midge species were collected with UV-light traps on 10 farms in Germany, with one trap inside and one trap outside barns on each of the farms. Traps were run once a week for 24 h from January to December 2019. Collected biting midges were morphologically identified, counted and statistically evaluated, with a focus on the Obsoletus Group and the Pulicaris Complex of the ceratopogonid genus Culicoides, which are believed to contain the major virus vectors. Temperature and relative humidity recorded at each trap were linked to the quantity of caught Culicoides. Correlations between relative Culicoides abundance and presence of livestock or type of husbandry were also investigated. Results: A total of 38,886 Culicoides biting midges were trapped, with most of them belonging to the Obsoletus Group (51.0%) and the Pulicaris Complex (38.8%). The majority of captured specimens were collected in traps inside the barns. Obsoletus Group individuals were caught from late January to the last week of December while Pulicaris Complex individuals were captured from the end of March to early December. The lowest average temperatures at which members of the two groups were collected were 10.7 °C and 12.8 °C, respectively. While temperature had a statistically significant effect on the activity of both the Obsoletus Group and the Pulicaris Complex, relative humidity only significantly affected the activity of the latter. The presence of livestock significantly influenced the number of captured Obsoletus Group, but not of Pulicaris Complex specimens. Inside the barns, no statistical difference was found between numbers of caught Obsoletus Group and Pulicaris Complex specimens in livestock holdings with deep litter and manure scraper or slatted floor husbandry systems. Conclusions: The almost year-round presence of Obsoletus Group biting midges and the demonstrated high relative abundance of other potential Culicoides vector species inside barns suggest a high risk of indoor virus transmission to ruminants should BTV or SBV circulate locally. Appropriate structural, organisational and vector control measures to reduce biting midge exposure should be implemented. [ABSTRACT FROM AUTHOR]

In October 2023, bluetongue virus serotype 3 (BTV-3) emerged in Germany, where Schmallenberg virus is enzootic. We detected BTV-3 in 1 pool of Culicoides biting midges collected at the time ruminant infections were reported. Schmallenberg virus was found in many vector pools. Vector trapping and analysis could elucidate viral spread.

West Nile virus (WNV), a zoonotic arbovirus, has recently established an autochthonous transmission cycle in Germany. In dead‐end hosts like humans and horses the WNV infection may cause severe symptoms in the central nervous system. In nature, WNV is maintained in an enzootic transmission cycle between birds and ornithophilic mosquitoes. Bridge vector species, such as members of the Culex pipiens complex and Aedes spp., also widely distributed in Germany, might transmit WNV to other vertebrate host species. This study determined and compared the vector competence of field‐collected northern‐German Cx. pipiens biotype pipiens and laboratory‐reared Ae. vexans Green River (GR) for WNV lineage 1 (strain: Magpie/Italy/203204) and WNV lineage 2 (strain: "Austria") under temperatures typical for northern Germany in spring/summer and autumn. For assessment of vector competence, 7‐ to 14‐day‐old female mosquitoes were offered a WNV containing blood meal via Hemotek membrane feeding system or cotton‐stick feeding. After incubation at 18°C respectively 24°C for 14 days engorged female mosquitoes were salivated and dissected for determination of infection, dissemination and transmission rates by reverse transcriptase quantitative real‐time PCR (RT‐qPCR). Both Ae. vexans GR and Cx. pipiens biotype pipiens were infected with both tested WNV strains and tested 14 days post‐inoculation. Disseminated infections were detected only in Ae. vexans GR incubated at 18°C and in Cx. pipiens pipiens incubated at 24°C after infection with WNV lineage 1. Transmission of WNV lineage 1 was detected in Cx. pipiens pipiens incubated at 24°C. These results indicate that Cx. pipiens pipiens from Northern Germany may be involved in the transmission of WNV, also to dead‐end hosts like humans and horses. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Following the emergence of Schmallenberg virus (SBV) in 2011, 21,397 culicoid biting midges (Diptera: Ceratopogonidae) from targeted and non-targeted sampling activities carried out during the summer months of 2011 to 2013 and in late 2014 in various regions in Germany were analyzed for the virus by real-time RT-PCR. While no SBV was found in biting midges collected during 2011 and 2013, 2 out of 334 pools including 20 and 22 non-engorged females of the Obsoletus complex sampled in 2012 tested positive for the SBV S-segment with C values of 42.46 and 35.45. In addition, 673 black flies (Diptera: Simuliidae) captured during the same studies were screened for the presence of SBV and proved negative. In late autumn 2014, biting midges were collected again in a limited study in eastern Germany after some cases of SBV infection had occurred in a quarantine station for cattle. Due to the unfavorable seasonal weather conditions, only few specimens were caught, and these were also negative for SBV. The German experience suggests that biting midge collections launched only after an outbreak and are not locally targeted may be ineffective as to virus detection. It rather might be advisable to collect biting midges at sentinel farms on a permanent basis so to have material available to be examined in the case of a disease outbreak. [ABSTRACT FROM AUTHOR]

Schmallenberg virus ( SBV) is a member of the family Bunyaviridae and mainly affects ruminants. It is transmitted by biting midges, first and foremost Culicoides spp., and causes congenital malformations reflected in arthrogryposis-hydranencephaly ( AH) syndrome. The aim of this study was to collect data on the emergence of SBV as a new arthropod-borne disease introduced into Europe in 2011. Germany was located in the core region of the 2011/2012 epidemic. Following two seroprevalence studies in the north-west of Germany in 2012, this study focused on the epidemiology and distribution of SBV throughout 130 small ruminant flocks in the whole country. Blood samples were obtained of 30 animals per flock and a SBV-specific questionnaire was used to collect operating data of the farms. The median within-herd seroprevalence for all 130 flocks tested was 53.3% with a total range from 0% to 100%. The median within-herd seroprevalence for goats was 30% [interquartile range ( IQR): 40.3%] and 57% for sheep ( IQR: 43.3%). Small ruminant flocks kept permanently indoors or housed overnight had a significantly lower seroprevalence than flocks kept permanently outdoors. In addition, this study revealed a significantly lower seroprevalence in the north-east of Germany. These results show that small ruminants in Germany are still at risk of contracting new SBV infections following incomplete seroconversion of flocks especially in the north-east of Germany. This might contribute to SBV becoming enzootic in central and northern Europe. Furthermore, the survey revealed that housing animals at least during mating and early pregnancy may reduce the risk of new SBV infections and may thus be an option to reduce losses as long as there is no licensed vaccine available on the German market. [ABSTRACT FROM AUTHOR]

Palearctic species of Culicoides (Diptera, Ceratopogonidae), in particular of the Obsoletus and Pulicaris complexes, were identified as putative vectors of bluetongue virus serotype 8 (BTV-8) on ruminant farms during the epizootic in Germany from 2006 to 2009. BTV may cause severe morbidity and mortality in ruminants and sporadically in South American camelids (SAC). However, the fauna of Culicoides spp. on SAC farms has not been investigated. Therefore, the ceratopogonid fauna was monitored on three farms with BTV-seropositive SAC in Germany. Black–light traps were set up on pastures and in stables from summer 2008 to autumn 2009. Additionally, ceratopogonids were caught in emergence traps mounted on llama dung and dung-free pasture from spring to autumn 2009. After morphological identification, selected Culicoides samples were analysed for BTV-RNA by real-time RT-PCR. The effects of the variables ‘location’, ‘temperature’ and ‘humidity’ on the number of Culicoides caught in black–light traps were modelled using multivariable Poisson regression. In total, 26 species of Culicoides and six other genera of biting midges were identified. The most abundant Culicoides spp. collected both outdoors and indoors with black-light traps belonged to the Obsoletus (77.4%) and Pulicaris (16.0%) complexes. The number of Culicoides peaked in summer, while no biting midges were caught during the winter months. Daily collections of Culicoides were mainly influenced by the location and depended on the interaction of temperature and humidity. In the emergence traps, species of the Obsoletus complex predominated the collections. In summary, the absence of BTV-RNA in any of the analysed Culicoides midges and in the BTV-seropositive SAC on the three farms together with the differences in the pathogenesis of BTV-8 in SAC compared to ruminants suggests a negligible role of SAC in the spread of the virus. Although SAC farms may provide similar suitable habitats for putative Culicoides vectors than ruminant farms, the results suggest that geographic and meteorological factors had a stronger influence on Culicoides abundance than the animal species. [ABSTRACT FROM AUTHOR]

Bluetongue disease (BT) has spread after the first reported outbreak more than 100 years ago to nearly all the tropical and temperate regions worldwide in a geographic band between the latitudes 40°N and 35°S. Bluetongue virus (BT) is transmitted by biting midges of the genus Culicoides to susceptible ruminants like sheep, cattle, goats, and wild ruminants. Probably due to the global warming the dispersal area of the transmitting Culicoides species and by this of the BTV expanded to northern regions up to the latitude 50°N. Independent of expansion of the insect vectors BTV serotype 8 was introduced into Central Europe in 2006. The source of the BTV 8 introduction is still unknown. In Central Europe the virus found a new insect vector, midges of the Culicoides obsoletus group, indigenous in Central and Northern Europe and highly adapted to ruminants, overwintering in the stables. In summer and autumn 2006 and in the following years BT spread from the tri-border region between Germany, the Netherlands and Belgium to all neighbouring countries up to Scandinavia and United Kingdom. In the naive and genetically highly susceptible European sheep and cattle population the disease killed more than 1.5 million sheep. Trade restrictions and secondary diseases increased the economic losses. The spread could be stopped by a mandatory vaccination campaign using inactivated serotype specific vaccines. By this Central Europe could be sanitated from BT. [ABSTRACT FROM AUTHOR]

Background Culicoides spp. play an important role in the transmission of several vector-borne pathogens such as Bluetongue and Schmallenberg virus in Europe. To better understand the biology of local Culicoides species, a study divided into three parts was performed in northeast Germany to elucidate the feeding activity patterns (study A), preferential landing and feeding sites (study B) and host feeding preferences (study C) of Culicoides spp. using cattle and sheep as baits. Methods In study A, the activity of Culicoides spp. was monitored over a 72 h period by collecting insects at regular intervals from the interior of drop traps with cattle or sheep standing inside. In study B, Culicoides spp. were directly aspirated from the coat and fleece of cattle and sheep during the peak activity period of Culicoides. In study C, Culicoides spp. were collected using drop traps with either cattle or sheep standing inside and located 10 m apart. Results In study A, 3,545 Culicoides midges belonging to 13 species were collected, peak activity was observed at sunset. In study B, 2,024 Culicoides midges were collected. A significantly higher number of midges was collected from the belly and flank of cattle in comparison to their head region. In study C, 3,710 Culicoides midges were collected; 3,077 (83%) originated from cattle and 633 (17%) from sheep. Nearly half (46.7%) of the midges collected from cattle were engorged, significantly more than the number of engorged midges collected from sheep (7.5%). Culicoides from the Obsoletus complex (C. obsoletus and C. scoticus) were the most common Culicoides species encountered, followed by C. punctatus. Other species identified were C. dewulfi, C. chiopterus, C. pulicaris, C. lupicaris, C. pallidicornis, C. subfascipennis, C. achrayi, C. stigma, C. griseidorsum and C. subfagineus, the last two species are reported for the first time in Germany. Engorged C. chiopterus were collected in relatively high numbers from sheep, suggesting that this species may have a preference for sheep. Conclusions An insight into the feeding behaviour of local Culicoides species under field conditions in northeast Germany was obtained, with implications for the implementation of control measures and midge-borne disease risk analysis. [ABSTRACT FROM AUTHOR]

Changing environmental conditions and human encroachment on natural habitats bring human populations closer to novel sources of parasites, which might then develop into new emerging diseases. Diseases transmitted by host generalist vectors are of special interest due to their capacity to move pathogens into novel hosts. We hypothesize that humans using forests for recreation are exposed to a broad range of parasites from wild animals and their vectors. A corollary of this is that new vector-host, parasite-host, and vector-parasite associations could eventually develop. Thus, we expect to observe atypical vector-host associations. Using molecular bloodmeal analysis via amplification of the mtDNA COI gene we identified the vertebrate hosts of Culicoides (Diptera: Ceratopogonidae) species in a sub-urban forest of Southwestern Germany. Bloodmeals were also checked for haemosporidian infections by amplifying a fragment of the mtDNA cyt b gene. We identified a total of 20 Culicoides species, thirteen of which fed on humans. From 105 screened bloodmeals we obtained high quality sequences for 77 samples, 73 (94.8%) originated from humans, two from livestock (Bos taurus and Equus caballus), and two from wild birds (Sylvia atricapilla and Turdus merula). We found that four Culicoides species previously assumed to feed exclusively on either birds (C. kibunensis) or domestic mammals (C. chiopterus, C. deltus, C. scoticus) fed also on humans. A total of six Culicoides abdomens were infected with avian haemosporidian parasites (Plasmodium or Haemoproteus), four of those abdomens contained blood derived from humans. Our results suggest that parasites of wild animals may be transferred to humans through infectious bites of Culicoides vectors. Further, we show that Culicoides vectors believed to be a specialist on specific vertebrate groups can have plastic feeding preferences, and that Culicoides are susceptible to infection by Plasmodium parasites, though vector viability must still be experimentally demonstrated. [ABSTRACT FROM AUTHOR]

To identify the vectors of bluetongue virus (BTV) in Germany, we monitored Culicoides spp. biting midges during April 2007-May 2008. Molecular characterization of batches of midges that tested positive for BTV suggests C. obsoletus sensu stricto as a relevant vector of bluetongue disease in central Europe. [ABSTRACT FROM AUTHOR]

Abstract  The outbreak of bluetongue (BTV-8) in many parts of north-western Europe led to efforts to curb the spread of the disease, particularly in farms with valuable livestock, as on a stud bull farm in Schmergow, Brandenburg, Germany. In the abundance of the putative BT vectors, Palaearctic Culicoides species, several vector control methods were applied in the hope for a reduction of the target insect populations. Insecticide-impregnated ear tags and regular treatments at 6-week intervals of all bulls with deltamethrin pour on were expected to achieve the desired control of the biting midges. Additionally, insecticide-treated mosquito fences circumventing much of the pens were tried for the first time against Culicoides. Two suction black-light traps (BioGents® sentinel traps) helped to monitor the densities of Culicoides and other haematophagous nematocera during the trial period from July to December 2007. Despite all efforts, the densities of Culicoides were not distinctly reduced. Several thousand midges were repeatedly recorded during one-night catches. Examinations of midges and other haematophagous nematocera (Aedes and Anopheles species) revealed high percentages of successful feedings between 10% and 35% for Culicoides and more than 50% for Aedes and Anopheles species. Since all insects were caught inside the pens, the concept of endophily vs exophily or endophagy vs exophagy for some Culicoides species needs to be revised accordingly. Also, stabling of valuable livestock does not reduce the host–vector interface and, hence, the risk of transmission of BT. [ABSTRACT FROM AUTHOR]

Abstract  Within the countrywide monitoring of Culicoides species established by the German Federal Ministry of Food, Agriculture and User Protection (BMELV), the group Regensburg evaluated nine BG-Sentinel™ Midge traps located at cattle farms in the federal states Baden-Württemberg (BW) and Bavaria (BY) between March 2007 and May 2008. The highest numbers of midges were found in the months October and August. BTV serotype 8 genome was detected in four batches in the months September and October 2007. [ABSTRACT FROM AUTHOR]

Abstract  The unforeseen outbreak of bluetongue in north-western Europe in August 2006 raised the question, which Culicoides spp. were involved in the transmission of bluetongue virus (BTV). Based on the decision 2007/20/EU of December 2006, a large-scale entomological surveillance programme was initiated in the five affected EU member states including Germany. This paper reports on the entomological findings obtained from March/April 2007 to May 2008 at 15 sampling sites in the federal states of Lower Saxony (eastern region), Mecklenburg-Western Pomerania, Brandenburg and Saxony-Anhalt: The number of captured biting midges in one trap varied from none or few Culicoides during winter (December 2007 to April 2008) to up to more than 12,500 individuals during summer and autumn. Catches of the C. obsoletus group were consistently higher than those of the C. pulicaris group. C. imicola, the principal afro-asiatic vector of BTV, was not detected. High numbers of midges were caught inside the cattle sheds. Eleven pools of biting midges were RT-PCR-positive to BTV-8 including pools of non-engorged midges of the C. obsoletus and of the C. pulicaris groups. The first BTV-genome positive pool of midges was detected in August 2007; the remaining genome-positive pools were detected during October and November 2007. [ABSTRACT FROM AUTHOR]

Abstract  Due to the severe outbreaks of bluetongue disease (BTD) in the years 2006/2007 in Germany in the absence of the main African vector Culicoides imicola, a rapid and easy applicable method for identification of autochthonous Culicoides spp. had to be developed. Morphological identification is time-consuming, rendering impossible the identification of large numbers of midges in a short period of time. A polymerase chain reaction (PCR)-based procedure in connection with a species-specific primer greatly simplifies the identification process. The region of internal transcribed spacer 1 (ITS-1) of the ribosomal DNA has shown great potential for developing a reliable PCR-based procedure. Culicoides midges were caught with ultraviolet-light traps installed on different farms in Germany during 2007 and 2008. The midges were mounted on slides and morphologically characterised. Midge DNA was extracted and the ITS-1 region amplified using conservative primers. Potential primer regions within ITS-1 were determined and a species-specific Culicoides dewulfi primer was developed to correctly identify autochthonous C. dewulfi, one of the suspected BTV vectors in northwestern Europe. The developed primer was used to identify C. dewulfi in a pool of Culicoides midges from a farm in the state of Brandenburg. [ABSTRACT FROM AUTHOR]

Abstract  The entomological monitoring programs done on 19 farms all over Northrhine-Westfalia (Germany) in the years 2007 and 2008 showed that the species Culicoides obsoletus and C. pulicaris are the most common ones and that both act as vectors of the bluetongue-virus of the serotype 8. Especially the species C. obsoletus was found all over the year and also inside or close to stables during the winter months. Therefore, there exists no midge-free period that would interrupt the transmission cycle of bluetongue virus. This makes it necessary that vaccination programs and insecticidal treatment have to consider this and must be preceded even in winter months. From the fact that there was no northward migration of southern Culicoides species (e.g., Culicoides imicola), apparently, globalization and its intense transportation of animals, plants, and other goods is the reason of this BTD outbreak in Central Europe. This conclusion needs urgently special attention on other luring epidemics in the near future. [ABSTRACT FROM AUTHOR]

Abstract  The outbreak of bluetongue disease in Central Europe necessitates new approaches in the identification of vectors to follow-up changes of populations of species and not of complexes. Since females of species of the complex of Culicoides obsoletus are difficult to be identified according to morphological criteria, we applied a polymerase chain reaction (PCR)-based strategy targeting the mitochondrial cytochrome oxidase subunit I to differentiate between the species Culicoides obsoletus s.s. and Culicoides scoticus. Catches of culicoids obtained from May to November 2007 in an ultraviolet lamp trap at a cattle farm in Rhineland-Palatinate, Southern Germany were surveyed for changes of the abundance of both species. Only in May 2007, the samples contained similar proportions of both species. Afterwards, C. scoticus dominated with up to 88%. Calculating the number of specimens of both species within the total catches of culicoids, the numbers of C. obsoletus s.s. slightly decreased from May to July and increased to a little maximum in August. C. scoticus seemed to have three maxima in this period of time, the strongest one in August, presumably due to different generations and not to climatic conditions. These results indicate that the applied PCR strategy can be used for a detailed analysis of culicoids as basis for the estimation of the transmission risk of the bluetongue virus by different species of the Obsoletus complex. [ABSTRACT FROM AUTHOR]

Abstract  Host feeding patterns of engorged sibling species of the Culicoides obsoletus and Culicoides pulicaris groups captured during three nights on two selected farms maintaining either cattle, sheep, horses, and pigs (Seedorf, Brandenburg) or cattle, sheep, moufflons, and red and fallow deer (Paulinenaue, Brandenburg) were determined by polymerase chain reaction amplification using conserved primers and sets of species-specific primers derived from vertebrates mitochondrial cytochrome b. Out of a total of 177 blood meals analysed, 115 (65%) tested positive for a blood meal from vertebrates. 63.5% (n = 73) of the cyt b positive specimens could be further assigned down to the species level. Cattle appeared to be the most attractive hosts for Palaearctic biting midges (79.5%, n = 58) even if other large vertebrates were kept in their immediate vicinity. If pigs or horses were additionally maintained on a farm, they were likewise attacked by biting midges but at a distinctly smaller rate than cattle (pigs 13.7%, horses 2.7%). In this study, game animals appear to be less attractive than cattle since only a few engorged midges had taken a blood meal from red deer (4.1%). None of the blood meals analysed tested positive for sheep. Preliminary results reveal that biting midges of the C. pulicaris and C. obsoletus groups can feed on a range of vertebrate hosts but with a distinct preference for cattle even if other livestock are maintained in adjacent areas. [ABSTRACT FROM AUTHOR]

Abstract  Entomological monitoring was carried out from April 2007 to May 2008 at 20 locations in the areas of Lower Saxony, Schleswig-Holstein, Hamburg, and Bremen. A total number of 26 Culicoides species were sampled by light traps during the first week of every month. Culicoides diversity was highest in summer, achieving more than 20 species and genera per month. Numbers of Culicoides were highest in spring and summer with a maximum of 325,000 individuals in May 2008 at a single location. During the winter, the number of individuals decreased considerably, but few individuals of Culicoides were present even during the coldest months in January and February with Culicoides obsoletus remaining the only species complex. The total number of Ceratopogonidae and the number of individuals from C. obsoletus complex and Culicoides pulicaris complex were significantly correlated with temperature almost at any date and location. [ABSTRACT FROM AUTHOR]

Abstract  The paper reports the first detection of besnoitiosis of cattle in Germany. Just 2 years after the first appearance of the African Bluetongue disease (BTD) of cattle in Central Europe, another African agent of disease has arrived in Germany. While it was proven that the BTD virus was transmitted (after its first appearance) by endemic midges of the genus Culicoides (C. obsoletus, C. pulicaris), nothing is known, how the infectious stages of Besnoitia besnoiti—a member of the so-called cyst-forming coccidia—found their way to a herd in Southern Germany. The infected animals showed all characteristic clinical symptoms of besnoitiosis such as hyposclerodermia, hyperkeratosis, alopecia, and whitish tissue cysts in subcutaneous tissues as well as in the cornea. These cysts had diameters of up to 3 mm and consisted of a dense outer layer (=secondary cyst wall), which surrounded a host cell, that had been enormously enlarged by an inner parasitophorous vacuole containing thousands of 7–9 × 2 μm sized, banana-shaped cyst merozoites (=cystozoites, bradyzoites).Their fine structure was identical to that of published stages of B. besnoiti. During cyst development, the nucleus of the host cell had been hypertrophied and had apparently undergone several divisions, since many flattened, but very large nuclei were seen in light and electron microscopy. Thus, this study proves the arrival of another serious agent of disease of ruminants in Central Europe—a fact which is especially important, since in this species, there is neither information on the way of transmission from animal to animal nor exists concrete information on an efficacious therapy or on the modalities of its import into Germany. [ABSTRACT FROM AUTHOR]

Abstract  The paper offers the genebank accession numbers of Culicoides obsoletus, Culicoides scoticus and Culicoides pulicaris sequences (ITS 1, ITS 2, 18S rRNA) that had been shown to be vectors of the bluetongue virus serotype 8, which was introduced in 2006 into Germany and spread until 2009 all over Central Europe, including parts of England. The numbers are FN 263292 until FN 263323. [ABSTRACT FROM AUTHOR]

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.