The investigation of Culicoides (Diptera: Ceratopogonidae) species and Bluetongue virus and Schmallenberg virus in Northwest Türkiye.

Culicoides biting midges (Diptera: Ceratopogonidae) act as mechanical and biological vectors of arboviruses and are crucial in the global spread of these viruses. This study investigated the diversity of distribution of Culicoides species and the presence of Bluetongue virus (BTV) and Schmallenberg virus (SBV) in Tekirdağ province in Northwest Türkiye. The fourteen Culicoides species, such as Culicoides newsteadi, Culicoides schultzei, Culicoides nubeculosus comp., Culicoides punctatus, Culicoides circumscriptus, Culicoides obsoletus comp., Culicoides gejgelensis, Culicoides festivipennis, Culicoides longipennis, Culicoides spp., Culicoides pulicaris, Culicoides picturatus, Culicoides odiatus, Culicoides kurensis, and Culicoides flavipulicaris, were detected. Culicoides newsteadi, C. odiatus, and C. pulicaris were the most abundant species. Phylogenetic analyses of Culicoides species' ITS-1 gene region were performed. A pool of C. festivipennis was positive for SBV RNA, while the BTV genomic materials was not found in the qPCR analysis. This is the first report of the presence/detection of SBV in Culicoides species in Türkiye. The survey of bioecological and epizootiological aspects of vector species is essential in implementing effective control measures for arboviral infections.