Siphlonurus davidi

A detailed re-description of the mayfly species Siphlonurus davidi, found exclusively in Jiuzhaigou Valley, Sichuan Province, China, challenges previous diagnostic criteria used to distinguish it from closely related species. The study examines 198 specimens (65 nymphs and 133 imagos) collected between 2013 and 2023, providing comprehensive morphological descriptions of both life stages. Key findings include the identification of consistent diagnostic features in nymphs—such as reddish-brown oblique stripes on abdominal sterna and posterolateral spines—and distinct color patterns in adult males and females. Notably, the research debunks three proposed diagnostic traits by Yang et al. (2023), demonstrating that sclerotization patterns of the penis lobes and spine development are similar across S. davidi, S. dongxi, and a newly described species, S. orientalis. This work clarifies taxonomic confusion in the genus Siphlonurus, offering critical insights for future biodiversity studies in this UNESCO World Heritage Site.

Qiang, X.-H., & Zhou, C.-F. (2025). Siphlonurus davidi. Zenodo. https://doi.org/10.5281/ZENODO.18246748