Stictochironomus属(双翅目:Chironomidae)几乎在世界范围内分布,超过30种。然而,基于翅膀和腿上标记的物种定界和识别是有争议和不确定的。在这项研究中,我们专注于颜色模式来回顾来自中国的该属的成虫,和两个新物种(S.trifuscipessp.11月。和S.quadrimaculatussp.11月。)被描述和计算。DNA条形码可以准确地将具有特定颜色模式的两个新物种分开。然而,异源个体在系统发育树中形成单系簇。例如,S.Maculipennis(Meigen)和S.pictulus(Meigen),具有较低的种间遗传差异,形成一个单一的进化枝。具有相同物种名称但具有高种内距离的序列形成多个系统发育进化枝,例如三个分支的S.sticicus(Fabricius),美国四个分支的皮球,S.akizukii(Tokunaga)和S.jomaiiQi,施,和两个分支的王,可能有潜在的隐秘物种多样性。使用ASAP进行物种定界分析,PTP,GMYC明确将它们划分为单独的物种。因此,颜色图案是Stictochiromus物种划界的良好诊断特征。基于距离的分析表明,4.5-7.7%的阈值适用于Stictochironomus的物种划界。此外,提供了最新的密钥,包括来自中国的已知Stictochironomus物种的雄性成虫的颜色模式变化。
The genus Stictochironomus (Diptera: Chironomidae) has an almost worldwide distribution, with more than 30 species. However, species delimitation and identification based on the markings on the wings and legs are controversial and uncertain. In this study, we focused on color patterns to review the adults of the genus from
China, and two new species (S. trifuscipes sp. nov. and S. quadrimaculatus sp. nov.) are described and figured. DNA barcodes can accurately separate the two new species with specific color patterns. However, heterospecific individuals form a monophyletic cluster in the phylogeny tree. For example, S. maculipennis (Meigen) and S. pictulus (Meigen), which have a lower interspecific genetic divergence, form a single clade. Sequences with the same species name but with high intraspecific distance form more than one phylogenetic clade, such as S. sticticus (Fabricius) of three clades, S. pictulus of four clades, S. akizukii (Tokunaga) and S. juncaii Qi, Shi, and Wang of two clades, might have potential cryptic species diversity. Species delimitation analysis using ASAP, PTP, and GMYC clearly delineated them as separate species. Consequently, color patterns are a good diagnostic characteristic for species delimitation in Stictochironomus. The distance-based analysis shows that a threshold of 4.5-7.7% is appropriate for species delimitation in Stictochironomus. Additionally, an updated key including color pattern variation for male adults of known Stictochironomus species from
China is provided.