Metatranscriptomic Analysis Reveals the Virome Diversity of Biting Midges in Important Natural Scenic Areas of Beijing-Tianjin-Hebei Region, China

Background: Biting midges are important medical and veterinary vectorinsects that can transmit a range of zoonotic viruses. The Beijing-Tianjin-Hebei (BTH) region, as the core area in northern China, is rich in tourism resources, but the characteristics of the virome of biting midges in this region remain unclear. Results: A total of 12152 biting midgesindividuals were collected, and 7 species of Culicoides were identified. Culicoides punctatus (67.02%) and Culicoides morisitai (19.01%) were the dominant species. Metatranscriptomic sequencing yielded 9.79 billion reads, which were assembled into 19472821 contigs, with 45369 annotated viral sequences. Virome analysis showed that RNA viruses predominated, and positive-sense single-stranded RNA ((+)ssRNA)viruses accounted for the highest proportion. Geographic and host species factors significantly affected the viral composition (PERMANOVA, P<0.05). Phylogenetic analysis identified 22 virus species with 208 sequences, including 4 known viruses and 18 potential novel viruses, among which arbovirusessuch as Gouleako virus are worthy of attention. Conclusion: This study is the first to systematically reveal the diversity characteristics of the Culicoides virome in the BTH region and discover a variety of potential novel viruses, which provides an important scientific basis for the monitoring and prevention of regional arboviruses. The results emphasize the ecological importance of Culicoides as virus hosts, suggesting the need to strengthen ongoing monitoring of vector-borne viruses in this region.