A new freshwater opecoelid species, Sphaerostoma tamarae sp. nov., is described from Rhynchocypris percnura mantschurica caught in the Syumnyur River (Amur River basin, Russia). This parasite species differs from all other congeners in the distribution of the vitelline follicles (restricted to the hindbody) and the morphology of the ventral sucker (strongly protuberant). Molecular phylogenetic analysis based on 28S rRNA gene sequences and the morphological analysis allow to tentatively assign the new species to the genus Sphaerostoma, without closing the question regarding the true genus affiliation of this species. In addition, the authors provide an argument for renaming the Plagioporinae to the Sphaerostomatinae.

Here I explore the biological relevance, origin and meaning of the concept of cladogram (rooted, directed branching diagrams representing the hypothesized phylogenetic relationships among the terminal taxa under study) and argue that cladograms do not necessarily entail synapomorphies, but synapomorphies are required to test and ultimately falsify cladograms. Both cladograms and synapomorphies are required to achieve phylogenetic explanation. I conclude that within a phylogenetic, scientific context, testability refers to the logical relationship among cladograms (hypotheses), synapomorphies (evidence), and background knowledge (descent with modification). It is the relationship between evidence and hypothesis that underlies a logically consistent relationship between synapomorphies and cladograms. The capacity of a given cladogram, as a hypothesis, to explain synapomorphies complements this relationship and conforms phylogenetic explanation.

In this study, we review the Rheotanytarsus acerbus species group based on adult males from China. Two new species, R. cangshanensis Lin & Yao, sp. nov. and R. yamamotoi Lin & Yao, sp. nov., are described. R. adjectus (Johannsen, 1932) is re-described for its new record from China. A world key to adult males of acerbus species group is provided for the first time.

Based on available records, a comprehensive overview of the biodiversity and geographical distribution of Collembola in China is presented. A total of 735 species, 155 genera and 20 families were recorded in the checklist, including current name information, synonyms, geographical records, and bibliographic references. Taxonomic notes were added where necessary and Chinese translations were provided for genera and families. The following new combinations are proposed: Rambutsinella grinnellia (Wang, Chen & Christiansen, 2004) comb. nov. for Pseudosinella grinnellia Wang, Chen & Christiansen 2004; Rambutsinella hui (Wang, Chen & Christiansen, 2003) comb. nov. for Pseudosinella hui Wang, Chen & Christiansen 2003; and Rambutsinella tridentifera (Rusek, 1971) comb. nov. for Pseudosinella tridentifera Rusek 1971. In addition, certain species have been merged with their synonyms. This checklist includes articles published up to August 2023.

The genus Diomus Mulsant, 1850 (Coleoptera: Coccinellidae: Diomini) from China is herein revised. Five species of Diomus are occurring in the Chinese fauna to date, including a new species from the Dafushan Mountains Forest Park, Guangzhou, Guangdong, namely D. dafushanensis Bi, Peng & Chen, sp. nov. Nomenclatural history, diagnosis, illustrations and distribution were provided for each species. A key to the native species of Diomus from China is also presented.

China has the sixth-largest bee fauna with over 1,300 documented species. Yet countless more are expected, making taxonomic work an imperative. Here, we outline the history of bee taxonomy in China and discuss how best we can move into the future and describe all of the many undescribed species remaining. Key challenges include the difficulty of accurately assigning species names due to overseas type material as well as a general need for increased internationalization such as in specimen and data sharing. Only with sustained funding for basic taxonomy will it be possible to know and protect China’s unique bee fauna.

Two new species of the genus Trypoxylon, namely T. flavimaculatum Fu & Li, sp. nov. and T. tuberantennatum Fu & Li, sp. nov., are described and illustrated from Guizhou, Guangdong, Guangxi and Zhejiang Provinces, China. Another two species, T. chosenense Tsuneki, 1956 and T. konosuense Tsuneki, 1968, are newly recorded from China.

Ancient Lake Baikal (LB) is the prime hotspot of the harpacticoid diversity. The Canthocamptidae harpacticoids in the lake can be considered at least six species flocks. The lacks of unequivocal diagnostic characters in the family species description often lead species identification to an impasse. Recently developed molecular techniques provide a powerful tool to subject copepod taxa to comparative analyses. In order to provide a new base for canthocamp-tids taxonomy and clarify the systematic in some species flocks, we analyzed the mitochondrial DNA marker COI of 103 harpacticoid specimens from LB belonging to five genera. The materials were obtained from different lake basins from the depths 0.2‒1632 m. Using DNA barcoding, we identified 23 genetic species or groups of species, it was almost 1.5 times less than number of morphological species, and divergence of some molecular lineages were not corresponding to morphological species. Results of our study were the discovery of a new species, males of some morphological species, for which only females were previously described, clarification of the level of morphological variability of some species, etc. Specifically, it became apparent that morphological and genetic harpacticoid species diversity in LB differ significantly and it has to be detected strictly in complex.

The amber sites from the Chiapas Highlands in southwestern Mexico constitute an Oligo-Miocene Amber-Lagerstätte (ca. 24 Ma) whose mines and pits at Simojovel, Totolapa, and Estrella de Belén yield exceptionally preserved fossil inclusions, notably insects from an estuarine wetland. A comprehensive cross-referenced catalog of insects and their close relatives (Arthropoda: Hexapoda) recorded in Mexican amber has been compiled. The catalog comprises 589 fossil records, including 21 orders, 180 families, 230 genera, and 193 species. Data show the fossil diversity of insects based on 65 years of taxonomic descriptions. The catalog also consists of an online database for consultation and permanent updating. Accordingly, the taxonomic composition of Hexapoda in Oligo-Miocene Mexican amber is a significant addition to the current knowledge of the diversity of Lagerstätte taxa distributed worldwide.

Specimens of the crane fly genus Helius Lepeletier & Serville, 1828 from Sichuan, China are examined and studied. Three Helius species all belonging to the nominotypical subgenus are recognized, of which H. (H.) pallidissimoides Xu, Ma & Zhang, sp. nov. is described and illustrated as new to science, and H. (H.) pallidissimus Alexander, 1930 and H. (H.) franckianus Alexander, 1940 are redescribed and illustrated. For the first time, descriptions and illustrations are provided for the male of H. (H.) pallidissimus and the female of H. (H.) franckianus.

Siberian taimen Hucho taimen (Pallas, 1773) is a broadly distributed and popular sport fish with high economic value. However, low abundance and hard-to-reach habitat make the Siberian taimen a relatively understudied species. Here we describe the morphological variability of two size groups of Siberian taimen juveniles from the eastern (Amur River basin) and western (Kama River basin) parts of the species distribution. The largest morphological differentiation of Siberian taimen juveniles was observed at the inter-basin level. In the Amur River basin, Siberian taimen juveniles also differed morphologically even at sites located at a distance of 20 km from each other, which may be explained by a small home-range inhabitation of juveniles leading to the formation of their morphotype determined by local environmental conditions. The pattern of allometry varies in taimen from different rivers, which could be related to the ontogenetic shift of ecological niches and the level of heterogeneity of the river environment.

Mitochondrial genomes of five Tykhepoda scolopendromorphs (Cryptopidae, Scolopocryptopidae and Plutoniumidae) are sequenced and analyzed using methods of comparative genomics to provide more information on the phylogeny of Scolopendromorpha. The locations of 22 tRNAs, 13 PCGs, and 2 rRNAs are annotated. The heavy chain of mitochondrial genomes are 14,841–15,619 bp in length. A+T % vary from 64.79% to 77.40%, and mitochondrial genomes are CG and AT skewed. The phylogenetic reconstructions showed the blind clade, recently named Tykhepoda, is monophyletic with high support values (BS = 100% and PP = 1).

Dentisphaera Páll-Gergely & Jochum, 2017 is a troglobitic land snails genus known to harbour only one species found in a single cave in North Vietnam. Based on recently collected specimens from China, three species, Dentisphaera lagredeae Chen, Grego & Páll-Gergely, sp. nov., Dentisphaera shzha Chen, Grego & Páll-Gergely, sp. nov. and Dentisphaera zhoui Chen, Lin & Páll-Gergely, sp. nov. are introduced as new to science. The distribution range of Dentisphaera is extended based on the collecting records of these new species.

This study provides detailed descriptions and illustrations of a new species, Psilota nigritarsa Huo & Zhao, sp. nov., and a newly recorded species in China, P. nigripilosa Shiraki, 1968. It also offers additional measurements for Psilota bashanensis Huo, Zhao & Liu, 2022. The paper proposes a reclassification of the P. innupta-group in the Palaearctic Region into two subgroups based on the morphology of the male genitalia. An updated taxonomic key for the species of the P. innupta-group within the Palaearctic Region is also provided.

Four cynipid gall wasps belonging to three genera are reported with descriptions of their host plants and galls, i.e., Belizinella vicina Kovalev, 1965, Cerroneuroterus folimargo (Monzen, 1954), C. monseni (Dettmer, 1934) and Neuroterus hakonensis Ashmead, 1904. The genus Belizinella and three species, B. vicina, C. monseni and N. hakonensis, are recorded in China for the first time. The species B. vicina is redescribed for the missing or incongruent features from its original description. In addition, the gall host for Ufo rufiventris Wang, Guo, Wang, Pujade-Villar & Chen is also recorded here for the first time.

Eucotylidae is a family of microphalloid digeneans parasitising as adults in the urinary system of birds. There are few molecular data on members of this family, and phylogenetic relationships of its genera and species are still unclear. Here we present new morphological and molecular data on a eucotylid species Tanaisia atra (Nezlobinsky, 1926). Specimens of T. atra were found in Eurasian Coot Fulica atra Linnaeus, 1758 in European and Asian parts of Russia and examined using optical and SEM microscopy and molecular techniques. We report the presence of a well-developed cirrus sac and different types of tegumental scales in this species for the first time. All molecular markers used in our study (ITS2 region, 28S rRNA and cox1gene) indicate that T. atra isolates from European and Asian parts of Russia are conspecific. In phylograms based on ITS2 region and 28S rRNA gene sequences, T. atra clustered with other Tanaisia spp.

Baraeus orientalis Aurivillius, 1907, an African longhorn beetle belonging to the Cerambycidae family and the Lamiinae subfamily, has previously been reported in various countries on the African continent. This study identifies Adenia globosa Engler, 1891, a succulent plant with medicinal and aesthetic value, as a new host plant record for B. orientalis. The discovery occurred during a phytosanitary inspection at Hong Kong International Airport, where an adult longhorn beetle was intercepted on a stem of A. globosa. This finding emphasizes the potential risk of introducing invasive species and underscores the importance of implementing stringent quarantine measures. It also enhances our understanding of the host of B. orientalis, which was previously undocumented.

In the Homoneura (Homoneura) picta group, H. (H.) dahanshanensis Liu & Shi, sp. nov. is described as new to science and H. (H.) picta (de Meijere, 1904) is supplemented with detailed descriptions of significant intraspecific variations in abdominal striping patterns and structures of the syntergosternite and hypandrial apodeme. Photographic illustrations of these variations are also provided. A key to the 7 species of the group in China is presented.

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The subgenus Dendrotipula was distributed in Palaearctic Region. Only eight species of the subgenus Dendrotipula Savchenko, 1964 were known to occur worldwide, two species were described in China. Based on new collections, we described one new species from Southwest China, Tipula (Dendrotipula) dorsigera Q.C. Yang, sp. nov. A key to the species of Tipula (Dendrotipula) from world is presented.

The taxonomic status of Episoriculus umbrinus has been contentious. This study aims to clarify its taxonomic position through mitochondrial genome analysis. Specimens of E. umbrinus were obtained from Liupanshui City, Guizhou Province, China. Genomic DNA was extracted, and 15 primer pairs were designed to amplify and sequence the complete mitochondrial genome of E. umbrinus. The results revealed that the mitochondrial genome of E. umbrinus is a circular double-stranded structure with a length of 17,073 bp, comprising 13 protein-coding genes, 1 control region, 22 tRNA genes, 2 rRNA genes, and 1 origin of L-strand replication. Compared with E. caudatus, differences were observed between the two species in terms of replication origins, gene overlap regions, base lengths, and termination codons. Genetic distance analysis of mitochondrial protein-coding genes showed that the genetic distance between E. umbrinus and E. caudatus ranged from 0.069 to 0.125. A phylogenetic tree constructed based on the concatenated sequences of the 13 protein-coding genes indicated that E. umbrinus clustered as a distinct branch with the other three species within the genus Episoriculus. This study confirmed at the molecular level that E. umbrinus is an independent species rather than a subspecies of E. caudatus. The mitochondrial genome sequence of E. umbrinus provides an important supplementary information for the genetic research of this species and offers new evidence for the phylogenetic study of the tribe Nectogalini.