Two new species of Nemouridae, Illiesonemoura qianae Du, Zhao, & Rehman sp. nov. and Nemoura longistyla Zhao, Rehman & Du sp. nov., are described and illustrated from Yunnan Province of southern China. The morphological characteristics of the new species are compared to related taxa and new images are also provided.

The type species of Filchneria Klapálek, 1908, F. mongolica (Klapálek, 1901), is based on a single female collected from Mongolia, but it was considered the same as another species, F. songi from Qinling, China, when the genus Filchneria was proposed. This study narrates the story of these two species, which have been confused for a century. Until now, the distribution of F. mongolica has been confirmed only in Mongolia and Russia, and we recently recorded it for the first time in Inner Mongolia as a new species record in China. Additionally, the genus Sinoperlodes is a junior synonym of Filchneria, as demonstrated by both the morphological and molecular analysis. Phylogenetic analysis based on the subfamily Perlodinae is provided, along with morphological and biogeographic comparisons of Filchneria and its relatives.

Two poorly known species of Kamimuria Klapálek, 1907, K. simplex (Chu, 1929) and K. tienmushanensis Wu, 1938, are redescribed and newly recorded for Mt. Wuyi, Fujian. Kamimuria cheni Wu, 1948 and K. crassispina Wu, 1948 are removed from the species list of Fujian. The morphological variability of K. tienmushanensis from different locations is also discussed in this paper.

A new species of the genus Suwallia Ricker, 1943 (Plecoptera, Chloroperlidae), Suwallia dengbasp. nov., is described from Tibet and Yunnan, southwestern China. A diagnosis and description of the adult habitus and aedeagal structure are illustrated with color images. Similarities in the terminalia with closely related species are discussed. In addition, an updated key to adult males of the Suwallia species of China is provided.

Capniidae are a family of stoneflies, also known as snow flies, who emerge in winter. The phylogeny of Capniidae is widely accepted to be based on morphological analysis. Until now, only five Capniidae mitochondrial genomes have been sequenced so far. In addition, sampling is required to determine an accurate phylogenetic association because the generic classification of this family is still controversial and needs to be investigated further. In this study, the first mitogenome of genus Isocapnia was sequenced with a length of 16,200 bp and contained 37 genes, including a control region, two rRNAs, 22 tRNAs, and 13 PCGs, respectively. Twelve PCGs originated with the common start codon ATN (ATG, ATA, or ATT), while nad5 used GTG. Eleven PCGs had TAN (TAA or TAG) as their last codon; however, cox1 and nad5 had T as their final codon due to a shortened termination codon. All tRNA genes demonstrated the cloverleaf structure, which is distinctive for metazoans excluding the tRNASer1 (AGN) that missed the dihydrouridine arm. A Phylogenetic analysis of the superfamily Nemouroidea was constructed using thirteen PCGs from 32 formerly sequenced Plecoptera species. The Bayesian inference and maximum likelihood phylogeny tree structures derived similar results across the thirteen PCGs. Our findings strongly supported Leuctridae + ((Capniidae + Taeniopterygidae) + (Nemouridae + Notonemouridae)). Ultimately, the best well-supported generic phylogenetic relationship within Capniidae is as follows; (Isocapnia + (Capnia + Zwicknia) + (Apteroperla + Mesocapnia)). These findings will enable us to better understand the evolutionary relationships within the superfamily Nemouroidea and the generic classification and mitogenome structure of the family Capniidae.

We examined specimens of the Haploperla Navás, 1934 from Sichuan and Qinghai provinces, China. Two new synonyms of Haploperla valentinae Stark & Sivec, 2009 are established: Haploperla triangulata Chen & Du, 2016 syn. nov. and Haploperla datongensis Chen & Du, 2016 syn. nov. We redescribed H. valentinae from China with new color images to facilitate the identification. In addition, we also provide supplementary descriptions and contemporary color images of H. tuanjiena Du & Chen, 2016.