A new, widespread genus of Baetidae from South Asia (Insecta, Ephemeroptera) Author Kaltenbach, Thomas https://orcid.org/0000-0001-8052-0388 Museum cantonal des Sciences Naturelles, Departement de zoologie, Palais de Rumine, Place Riponne 6, CH- 1005 Lausanne, Switzerland & University of Lausanne (UNIL), Department of Ecology and Evolution, CH- 1015 Lausanne, Switzerland thomas.kaltenbach@bluewin.ch Author Kluge, Nikita J. https://orcid.org/0000-0001-9741-7790 Department of Entomology, Biological Faculty, Saint-Petersburg State University, Universitetskaya nab., 7 / 9, Saint Petersburg, 199034, Russia Author Gattolliat, Jean-Luc https://orcid.org/0000-0001-5873-5083 Museum cantonal des Sciences Naturelles, Departement de zoologie, Palais de Rumine, Place Riponne 6, CH- 1005 Lausanne, Switzerland & University of Lausanne (UNIL), Department of Ecology and Evolution, CH- 1015 Lausanne, Switzerland text ZooKeys 2023 2023-07-03 1168 231 266 http://dx.doi.org/10.3897/zookeys.1168.104844 journal article http://dx.doi.org/10.3897/zookeys.1168.104844 1313-2970-1168-231 28A21391A4334E808845E5C0996EFAF0 6928794CB97051F9AAE3B64050E5FAF3 Arcobaetis gracilentus comb. nov. Nigrobaetis gracilentus : Kang et al. 1994 : fig. 7A-L. Diagnosis. Larva. Following combination of characters distinguish Arcobaetis gracilentus comb. nov. from other species of Arcobaetis gen. nov.: A) distal margins of segments in middle part of flagellum without long spines; B) labial palp segment III sub-quadrangular, at base narrower than distal margin of segment II ( Kang et al. 1994 : fig. 7E); C) hind protoptera present ( Kang et al. 1994 : fig. 7G); D) tergalii present on abdominal segments I-VII; E) posterior margin of tergum VI with triangular spines, longer than wide ( Kang et al. 1994 : fig. 7K). Distribution. Taiwan.