Discobola Osten Sacken, 1865 (Diptera, Limoniidae) in China: Taxonomic Review, Updated Distribution, and DNA Barcoding

The genus <i>Discobola</i> Osten Sacken, 1865 from China is taxonomically reviewed using an integrative approach that combines detailed morphological examination and molecular analysis. <i>Discobola parvispinula</i> (Alexander, 1947), a species widely distributed across the Palaearctic region, is newly recorded from China. Updated distributional data are presented for species known from China: <i>D. annulata</i> (Linnaeus, 1758), <i>D. armorica</i> (Alexander, 1942), <i>D. margarita</i> Alexander, 1924, and <i>D. taivanella</i> (Alexander, 1930). Detailed redescriptions and illustrations, including intraspecific morphological variation, are provided for these species. An identification key to Chinese <i>Discobola</i> species is also presented. Geographical analysis reveals a higher species richness in southern China and the Qinghai-Tibet region, with a progressive decline toward northern and northwestern China. The first DNA barcode reference library for Chinese <i>Discobola</i> is established, comprising 15 mt <i>COI</i> sequences from five species. These sequences, analyzed alongside an additional 101 mt <i>COI</i> sequences from <i>Discobola</i> species in other countries, show that intraspecific divergence within the genus remains below 7.4%, while interspecific divergence ranges from 7.6% to 17.7%. These findings provide important insights into the taxonomy, species delimitation, and biogeography of <i>Discobola</i> in China, contributing to a more comprehensive understanding of <i>Discobola</i> diversity across the region.