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Two New Species and First Stage Associations for Two Other Species of the Cincticostella nigra (Uéno, 1928) Complex (Ephemeroptera, Ephemerellidae) from Yunnan, China, with Discussion About Cincticostella Allen, 1971 Species Complexes Based on Winged Stages † †
by
, and
Yi-Fei Feng
1,2,‡
,
Yan-Chang Zi
1,2,‡,
Cheng-Fa Zhao
1,2,3,
Yuan Mu
1,2,3,
Xian-Fu Li
1,2,3,4,* and
Luke M. Jacobus
5,6,* 1
Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali 671003, China
2
Center for Interdisciplinary Sciences, Dali University, Dali 671003, China
3
Collaborative Innovation Center for Biodiversity and Conservation in the Three Parallel Rivers Region of China, Dali University, Dali 671003, China
4
Research Center of Ecology and Governance for Er’hai Lake Streams, Dali 671003, China
5
Division of Science, Indiana University Columbus, Columbus, IN 47203, USA
6
Department of Entomology, Purdue University, West Lafayette, IN 47907, USA
*
Authors to whom correspondence should be addressed.
†
† Zoobank: urn:lsid:zoobank.org:pub:3B7CF057-D4ED-461B-8826-6552B7452B05.
‡
These authors contributed equally to this work.
Insects 2025, 16(12), 1221; https://doi.org/10.3390/insects16121221
Submission received: 31 October 2025
/
Revised: 24 November 2025
/
Accepted: 24 November 2025
/
Published: 29 November 2025
(This article belongs to the Special Issue Aquatic Insects Biodiversity and eDNA Monitoring)
Simple Summary
The winged stages are very important for the classification of the genus Cincticostella Allen, 1971. Unfortunately, winged stages of most Cincticostella species are poorly known or unknown. Moreover, at least in China, there are a significant number of undescribed new species. The present study focuses on the winged stages of Cincticostella species from Yunnan, China. Two new species of Cincticostella xiazhi Zi, Li & Jacobus, sp. nov. and C. yushui Zi, Li & Jacobus, sp. nov. are described based on egg chorionic structure and nymph and winged stages, and the eggs and winged stages of C. wangi Selvakumar Martynov & Subramanian, 2021 and C. funki Martynov, Selvakumar, Palatov & Vasanth, 2021 are described for the first time. The delimitation of four species complexes in Cincticostella is discussed based on the winged stages. Additionally, a partial phylogenetic reconstruction of Cincticostella based on the COI gene is proposed and discussed. Finally, a key to the nymphs of the C. nigra complex is included.
Abstract
Four species of the Cincticostella nigra (Uéno, 1928) complex (Ephemeroptera, Ephemerellidae) from Yunnan, China are described based on egg chorionic structure and nymph and winged stages, including C. wangi Selvakumar Martynov & Subramanian, 2021, C. funki Martynov, Selvakumar, Palatov & Vasanth, 2021, and two new species, viz., Cincticostella xiazhi Zi, Li & Jacobus, sp. nov. and Cincticostella yushui Zi, Li & Jacobus, sp. nov. The egg and winged stages of C. wangi and C. funki are described for the first time. Eggs of all four species have macroreliefs generally similar to one another and to other species in the genus. Male imagoes have preliminary species-level differences in the median convex lobes of the styliger plate and the shapes of the penis lobes themselves. The current delimitation of four complexes of Cincticostella is briefly discussed based on the nymph and winged stages. A partial phylogenetic reconstruction of Cincticostella based on the COI gene illustrates relations of representatives of the four complexes on the one hand and distinct delimitation of C. wangi, C. funki, C. xiazhi, sp. nov., and C. yushui, sp. nov. on the other. An updated list of species of Cincticostella is provided, along with a new key for the identification of nymphs of the C. nigra complex, which are distinguished primarily based on features of the abdominal terga, mesothoracic projections, tarsal claws, labrum emargination, setation of femora, and body color.
Keywords:
spiny crawler mayflies; key; phylogeny; imago; Hengduan Mountains; Himalaya
