Diversity and seasonal abundance of Culicoides (Diptera, Ceratopogonidae) in Shizong County, Yunnan Province, China

Culicoides (Diptera, Ceratopogonidae) are small biting midges, some of which are vectors for animal associated arboviruses such as bluetongue virus (BTV) and Akabane virus (AKAV). BTV and AKAV are both pathogenic for livestock, with BTV in particular posing a major threat to domestic ruminants. Ongoing problems with BTV in ruminants in Shizong County of Yunnan Province, China, promoted a year-long investigation of the Culicoides in Shizong to determine relative abundance and seasonality of midges and to attempt to identify species that might be acting as vectors in the area. Culicoides were collected by UV light trap for one night per week for most weeks between May 2020 and May 2021. More than 21,000 specimens consisting of at least 21 species belonging to six subgenera and one unplaced group, including 5 species previously associated with BTV and one associated with AKAV, were collected. Culicoides tainanus dominated most collections throughout the year although C. sumatrae was often the dominant species over summer. Most species were abundant between May and October. These results indicate that C. tainanus, C. jacobsoni and C. oxystoma are the major midge pests of livestock in Shizong and should be considered in any disease investigation.