Overview of Indian and Nepali representatives of the Cincticostella nigra (Uéno, 1928) complex (Ephemeroptera, Ephemerellidae), with discussion about Cincticostella Allen, 1971 species complexes.

The concept of the Cincticostella nigra (Uéno, 1928) (Ephemeroptera: Ephemerellidae) complex is clarified and Indian and Nepali representatives of the complex are reviewed. Four new species are described viz. Cincticostella changfai Martynov & Palatov, sp. nov., Cincticostella funki Martynov, Selvakumar, Palatov & Vasanth, sp. nov., Cincticostella shinichii Martynov & Palatov, sp. nov. and Cincticostella wangi Selvakumar, Martynov & Subramanian, sp. nov. The larva of C. corpulenta (Braasch, 1981) is re-described, based on the holotype and paratypes. Cincticostella gosei (Allen, 1975) is recorded from India for the first time. Morphological differences of the species complexes of Cincticostella Allen, 1971 are analysed. A new species complex, Cincticostella gosei complex, is proposed. Summaries of distribution data and habitat preferences, as well as new larval diagnoses, are presented for all species of the Cincticostella nigra complex.