Diversity and Seasonal Abundance of <i>Culicoides</i> (Diptera: Ceratopogonidae) in Tengchong County of Yunnan, China.

Abstract

<i>Culicoides</i> (Diptera, Ceratopogonidae) are small biting midges and are known as vectors for many arboviruses, including bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). Tengchong County of Yunnan Province, China, which borders Myanmar, has many private farms with goats, sheep, and cattle. To estimate the risk of <i>Culicoides</i>-borne viral diseases such as bluetongue (BT) and epizootic hemorrhagic disease (EHD) in this area, an investigation of the diversity and abundance of <i>Culicoides</i> in Tengchong between May 2024 and April 2025 was performed. As a result, 70 collections totaling approximately 93,000 <i>Culicoides</i> were carried out at five farms (cattle + Asian buffaloes, goats, and sheep, respectively). Nineteen species were identified, and eight potential cryptic species were found. A total of 13 <i>cox1</i> sequences and 4 <i>28S</i> sequences for 13 specimens were generated. The most dominant species were Obsoletus (44.1%), <i>C. homotomus</i> (23.3%), and <i>C. arakawae</i> (12.9%) at the bovine farm; <i>C. tainanus</i> (68.0%), <i>C. orientalis</i> (12.6%), and <i>C. newsteadi</i> (Asia) (6.3%) at the goat farm; and <i>C. tainanus</i> (73.6%), <i>C. fenggangensis</i> (7.3%), and <i>C.</i> sp. nr <i>palpifer</i> (6.3%) at the sheep farm. In this investigation, <i>C. tainanus</i>, Obsoletus, and <i>C. orientalis</i> were the most dominant potential BTV vectors, and the period between July and October may be the main period for epidemics of <i>Culicoides</i>-borne viruses in Tengchong.