Redescription of two species of Neoperla Needham, 1905 (Plecoptera, Perlidae) and new distribution records of Neoperlamnong Stark, 1987 in China.

Background: Two species of Neoperla from Guizhou Province, China, N.bituberculata Du, 2000 and N.dashahena Du, 2005 were described with brief morphological descriptions available only in Chinese and original illustrations being somewhat blurry. Recently, we examined type material of these two species and re-described them with clear colour pictures for the first time. New information: In this paper, detailed English descriptions and colour pictures of Neoperlabituberculata and N.dashahena are provided for the first time. The type locality of N.mnong Stark is from Vietnam and its geographical distribution is also discussed. Additionally, we also recorded the distribution of N.mnong Stark, 1987 in Guizhou, Hunan and Jiangxi Provinces of China for the first time and provided a geographical distribution map of this species.

The First Complete Mitochondrial Genome of Genus Isocapnia (Plecoptera: Capniidae) and Phylogenetic Assignment of Superfamily Nemouroidea.

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.

The intraspecific morphological variability of Styloperla Wu, 1935 (Plecoptera: Styloperlidae).

Intraspecific morphological variability of four Styloperla Wu, 1935 species are described and discussed in this paper. The males of each species have variable specializations present at their basal cercal process, including the variable number of branches or differing degrees of curvature at the apical spines. A generalization on the species definition of Plecoptera, especially a new concept of conspecificity is also provided herein.

The second species of Neowuia Li & Murnyi, 2017 (Plecoptera: Perlodidae) from Fujian, China.

The second species of Neowuia Li & Murnyi, 2017, N. wuyishana sp. nov., is proposed with a description from Mount Wuyi, Fujian Province, southeastern China. Morphological features, namely adults and eggs, support Neowuia as a member of the tribe Diploperlini. Geographically, our study firstly reports the distribution of all Diploperlini in the Oriental region, while Neowuia is the second genus of subfamily Perlodinae recorded in southeastern coastal China.

The First Study of Mating Mistakes in Stoneflies (Plecoptera) from China, with Remarks on Their Biological Implications.

Currently, information on the biology of Plecoptera from China is scarce, particularly on mating behavior. In this paper, the existence of mating mistakes (erroneous mating attempts) involving 13 Chinese stonefly species (belonging to nine genera and three families) is reported. These erroneous mating behaviors can be included into three different categories: mating attempts between conspecific males (including the formation of erroneous mating balls), mating attempts between different taxa (including displacement attempts during copulation), and mating-related behaviors with non-living objects. From these behaviors, some aspects of stoneflies during mating, such as the physical competition between males, the sensorial mechanisms implied in triggering a mating behavior, the conditions favoring the mating mistakes, and the possible consequences of interspecific mating in the hybrid production, are discussed.

New Synonym and New Species Record of Filchneria (Plecoptera: Perlodidae) from China with a Morphological, Phylogenetic and Biogeographic Study on This Genus.

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 new synonyms of Haploperla valentinae Stark amp; Sivec, 2009 and supplementary redescription of H. tuanjiena Chen amp; Du, 2016 from western China.

We examined specimens of the Haploperla Navs, 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.

Three new species of Sinacroneuria Yang amp; Yang, 1995 (Plecoptera: Perlidae) from Zhejiang Province, southeastern China.

Three new species of Sinacroneuria Yang Yang, 1995, Sinacroneuria parallela Xiang Du, sp. nov., Sinacroneuria complana Xiang Du, sp. nov. and Sinacroneuria longiprojecta Du Huo sp. nov., from Zhejiang Province of southeastern China are described and illustrated. A list and provisional key to Sinacroneuria males of Zhejiang Province are also presented.

Notes on Perlodinella Klaplek, 1912 (Plecoptera: Perlodidae) with a new species and a new synonym.

After reexamining the syntype series of Perlodinella kozlovi Klaplek, 1912, a new species of Perlodinella, P. tibetensis Huo Du sp. nov. is proposed, and a lectotype is designated for P. kozlovi. Another monotypic genus of Perlodidae, Rauserodes Zwick (1999), is considered as a synonym of Perlodinella in this paper.

The first cavernicolous Leuctridae (Insecta: Plecoptera) nymph from Guizhou, China.

In this study, the first cavernicolous stonefly of China is reported from Guizhou Province, southwestern China. The morphological characteristics show that this species is a member of the genus Rhopalopsole Klaplek, 1912 (Plecoptera: Leuctridae). The pale coloration and the reduced compound eyes indicate that this species could be an obligate troglobitic taxon. The mtDNA COI barcode fragment of this species supports its assignment to Rhopalopsole and suggests it a distant relative to Rhopalopsole longispina Yang Yang, 1991.

A new species and new species group of Sweltsa Ricker, 1943 (Plecoptera: Chloroperlidae).

A new species of the genus Sweltsa Ricker, 1943, Sweltsa lateoblonga Rehman, Du Huo sp. nov. from Wanglang Nature Reserve, Sichuan Province, China, is described and compared with similar species. A new species group, Sweltsa recurvata group, is proposed for Sweltsa species that lack a transverse ridge on tergum 9. The new species, together with five recognized Palearctic and two Nearctic species, are included in the new group. A taxonomic key to species in this group is included. In addition, unidentified male and female specimens of Sweltsa recorded from Anzihe Nature Reserve, Sichuan Province, and its morphological differences with similar species are discussed with contemporary color images.

A discussion of morphological differences within Claassenia qingzanga Xiang, Huo amp; Du, 2022 (Plecoptera: Perlidae) based on molecular data and a redescription of C. magna Wu, 1948.

In the genus Claassenia Wu, 1934, the sensilla basiconica patch is an important identification characteristic, yet there are few studies that have investigated this trait. Recently, we found that tergum 8 of males of Claassenia qingzanga Xiang, Huo Du, 2021 collected from the Qinghai Province of China have a small, scattered basiconica patch, while the specimens collected from the Tibet Autonomous Region of China lack this characteristic. To verify their genetic relationship, we sequenced the mitochondrial cytochrome C oxidase subunit I gene of C. qingzanga collected from Tibet and Qinghai provinces. Phylogenetic analyses using Maximum Likelihood and Bayesian Inference methods, the two forms of C. qingzanga grouped together with strong nodal support and separate from the other Claassenia species analyzed. Genetic distance among these two forms of C. qingzanga is only about 1%. The molecular analyses confirmed that specimens with morphological differences are indeed the same species. A discussion of morphological differences within C. qingzanga and its genetic relationships are presented based on molecular data. Additionally, Claassenia magna Wu, 1948 is redescribed based on recent specimens.

A new species of the genus Sweltsa Ricker, 1943 (Plecoptera, Chloroperlidae) from Guizhou Province, China.

Background: Sweltsa is a genus of green stoneflies in the family Chloroperlidae and is distributed throughout the Nearctic and East Palaearctic Regions. As they are sensitive to pollutants, they are often used as an indicator species for determining the quality of water bodies. There are around 57 species of this genus worldwide and 11 of those have been identified from China. New information: A new species of the Alloperlini genus Sweltsa Ricker, 1943, Sweltsaligula Rehman, Huo & Du sp. n. is described from Kuankuoshui National Natural Reserve, Suiyang County, Guizhou Province, southwest China. This is the first report of the family Chloroperlidae from Guizhou Province. Diagnosis, description of male, female and nymph, illustration of terminalia and similarities with closely-related species are provided and discussed.

A new species of Suwallia Ricker, 1943 (Plecoptera, Chloroperlidae) from southwestern China, with an updated key to male Suwallia species.

A new species of the genus Suwallia Ricker, 1943 (Plecoptera, Chloroperlidae), Suwalliadengba sp. 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.

Mechanisms of fungal community assembly in wild stoneflies moderated by host characteristics and local environment.

Deterministic and stochastic forces both drive microbiota assembly in animals, yet their relative contribution remains elusive, especially in wild aquatic-insect-associated fungal communities. Here, we applied amplicon sequencing to survey the assembly mechanisms of the fungal community in 155 wild stonefly individuals involving 44 species of 20 genera within eight families collected from multiple locations in China. Analysis showed that fungal diversity and network complexity differed significantly among the eight stonefly families, and that the fungal communities in stoneflies exhibited a significant distance-decay pattern across large spatial scales. Both a structural equation model and variance partitioning analysis revealed that environmental factors (e.g., geographical, climatic) outweigh host attributes in shaping the fungal community of stoneflies. Using neutral and null model analyses, we also find that deterministic processes play a larger role than stochasticity in driving the fungal community assembly. However, the relative contribution of ecological processes including dispersal, drift, and selection, varied strongly with host taxonomy. Furthermore, environmental conditions also significantly affect the strength of these ecological processes. Overall, our findings illustrate that variations in host attributes and environment factors may moderate the relative influence of deterministic and stochastic processes to fungal community composition in wild stoneflies, which provides new insights into mechanisms of microbial community assembly in aquatic arthropods.

A new species of the genus Claassenia (Plecoptera: Perlidae) from China.

A new species, Claassenia qingzanga Xiang, Huo Du, sp. nov. is described from Tibet and Qinghai Province of western China, this is the first record of Claassenia in Qinghai-Tibet Plateau. Males of the new species are brachypterous, the apex of the aedeagus with tiny spines dorsally and with dense protrusion laterally. The new species is compared to all regional Claassenia.

A new species of Sweltsa Ricker, 1943 (Plecoptera, Chloroperlidae) and a supplementary description of Sweltsahamula Chen & Du, 2017 from China.

Background: The genus Sweltsa is a small to medium-sized stonefly with distinct coloured wings, giving the species the common name of green stoneflies. It belongs to the family Chloroperlidae. This genus includes more than 55 species world wide, 14 of which have been reported from China. New information: A new species of the genus Sweltsa Ricker, 1943, Sweltsaliupanshana Rehman, Du & Huo sp. nov. from Ningxia Hui Autonomous Region, Liupan Mountain, China is described; this is the second record of Sweltsa from Ningxia Hui Autonomous Region. In addition, the first female description and male supplementary description of Sweltsahamula Chen & Du, 2017 from Sichuan Province are provided. Diagnosis, description and colour illustration of the new species and of Sweltsahamula are provided and the morphological characteristics are compared with closely-related species.

Additions to the fauna and biology of stoneflies (Plecoptera) in Taizi River Basin, Liaoning, with seven new species records to China.

Background: An investigation report of stonefly fauna in Benxi Manchu Autonomous County, Liaoning Province, northeast China (used to be called Manchuria, now includes Liaoning, Jilin, Heilongjiang Provinces and parts of Inner Mongolia, which are adjacent to the Russian Far East and the Korean Peninsula). Materials were studied with field observation in 2018 and 2019. New information: This paper records five families, nine genera and 14 species of stoneflies from Taizi River, Liaoning Province. Nine species have been recorded for the first time in China and the biology of several common species is also reported for the first time.

Review of Kamimuria (Plecoptera: Perlidae) from Zhejiang and Fujian provinces, China, with notes on the morphological variability of K. tienmushanensis Wu, 1938.

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.