New record of of Baetis (Tenuibaetis) panhai Suttinun, Gattolliat & Boonsoong, 2022 (Ephemeroptera: Baetidae) from the southern Western Ghats, India

Baetis (Tenuibaetis) panhai Suttinun, Gattolliat & Boonsoong, 2022, originally documented solely in Thailand, has now been identified for the first time in the Tamil Nadu region of the Southern Western Ghats, India. Prior discrepancies in the description of Tenuibaetis frequentus Müller-Liebenau & Hubbard, 1985 including larval features such as the presence of hindwing pads, tergalius I and IV ratio, and the number of marginal spines in the paraproct, resulted in misidentification, with the species erroneously categorized as Tenuibaetis frequentus in Tamil Nadu until 2023. This comprehensive study involved a re-examination of Baetis (T.) panhai, leading to the accurate determination of its population in Tamil Nadu. Detailed larval characters of Baetis (T.) panhai were provided together with discussion about its taxonomic status and related taxa.