Analyzing the composition and structure of the gut bacterial community in Antheraea pernyi is essential for improving its economic traits, as well as for understanding gut bacteria-host interactions in lepidopteran insects. This study utilized the Illumina MiSeq PE 300 platform to conduct 16S rRNA gene sequencing for a comparative analysis of gut bacterial community in laboratory-reared and field-released (spring and autumn) Antheraea pernyi larvae of the same strain. The study revealed the specific effects of rearing environment and seasonal variation on the structural and functional dynamics of the larval gut bacterial communities. The composition of the dominant gut bacteria varied significantly with rearing environment and season. Laboratory-reared and spring field-released groups exhibited similar bacterial community structures, whereas the autumn field-released group showed a significant trend toward specialization, characterized by enrichment of specific bacterial taxa. Linear discriminant analysis effect size identified statistically significant biomarkers across samples. Taxonomic analysis revealed that Actinomycetota, Actinobacteria, Mycobacteriales, Dietziaceae, and Dietzia were characteristic of the gut bacteria profile in spring field-released, Lactobacillales, Enterococcaceae, and Enterococcus were enriched in the autumn field-released group, and the laboratory-reared group exhibited a relative dominance of Alphaproteobacteria. Functional prediction indicated that gut bacterial community structure likely influences its metabolic potential, which may suggest an adaptive response of the Antheraea pernyi to distinct ecological environments. This study provides important insights into the highly complex nature of insect-microbe interactions.

The genus Aberdareleria Woźnica, 1993 (Diptera: Heleomyzidae) was previously considered monotypic and endemic to the Aberdare Mountains, Kenya. Here, we describe A. qinghaiensissp. nov. from Qinghai Province, China, marking the first record of the genus outside the Aberdare Mountains in Kenya and revealing a remarkable Afrotropical-Palearctic disjunction (>6000 km). The new species differs significantly from A. freidbergi, in traits such as having reduced setae on the mid tibia (only anterodorsal and posterodorsal setae) and only spine-like setae on the female cercus (absence of hair-like setae). Through a taxonomic revision of the genus, we provide a diagnostic key, detailed morphological comparisons, and discuss the biogeographic implications of this transcontinental distribution, suggesting either ancient vicariance or avian-mediated dispersal. This discovery highlights the underestimated diversity of high-altitude Diptera in the Qinghai-Tibet Plateau.

The stalk-eyed flies (Diptera: Schizophora: Diopsidae) are a diverse clade of acalyptrate flies known for their remarkable eye stalks and intriguing courtship behaviours. Despite their striking appearance and significance as subjects for ecological and ethological studies, phylogenetic relationships within Diopsidae have not yet been comprehensively investigated, and the evolutionary history of the family remains inadequately resolved. We here present the first time-calibrated phylogenetic analysis of Diopsidae based on 17 genes ( 12S , 16S , 18S , 28S , and 13 mitochondrial protein-coding genes, 18 536 bp) from 48 taxa, including all extant subfamilies and ~76% extant genera of the family, thus clarifying a number of outstanding questions about intra-familial relationships and the evolutionary history of the stalk-eyed flies. Our results support the monophyly of Diopsidae and its three subfamilies; Centrioncinae is recovered as sister to the stalk-eyed lineage Sphyracephalinae + Diopsinae; the Teleopsis genus-group as well as several currently recognized genera are non-monophyletic and require further taxonomic review to better resolve their phylogenetic status. Molecular dating and biogeographic analyses indicate an African origin of the crown group of Diopsidae in the middle Eocene, ca. 45 Ma; its early diversification events might have been driven by climatic and ecosystem transformations during the middle Eocene to middle Miocene; available evidence suggests that factors shaping the current distribution of Diopsidae include colonization of Madagascar from Africa via the Mozambique Channel, out-of-Africa dispersals mediated by the Gomphotherium land bridge along with favourable environmental conditions, and colonization of North America via the Bering Land Bridge. This study provides a framework for future investigations into the evolutionary history of the stalk-eyed flies, as well as for ecological and morphological evolutionary research.

Sexual dimorphism is widespread in animals and often reflects evolutionary trade-offs between natural and sexual selection. Understanding the genomic and molecular mechanisms underlying these differences is key to revealing how adaptive traits evolve. Bibio rufiventris, commonly known as the fulvous-female march fly, exhibits striking sexual dimorphism, with males uniformly black and possessing enlarged compound eyes, while females display vivid reddish-orange thoraces and abdomens, making it an ideal model for investigating the genetic and molecular basis of sexually dimorphic traits. Here, we present a high-quality chromosome-level genome assembly of B. rufiventris. Comparative genomics revealed expansion of developmental and metabolic gene families in B. rufiventris, and branch-site analysis identified 265 positively selected genes, some of which are enriched in sensory-system development, including compound eye morphogenesis and multiple sensory perception processes. Transcriptomic profiling showed strong male-biased expression of phototransduction genes (eg ninaE, Arr2, and inaD) in heads, which may explain the enhanced visual processing capability in males. We also find a coordinated regulation pattern across melanin, pteridine, ommochrome, and heme-biliverdin pathways appears to underlie the female-specific coloration. These findings yield novel insights into sexual dimorphism in B. rufiventris in terms of pigment metabolism, visual system specialization, and sensory adaptation. This study also adds to our understanding of the genetic basis and evolutionary diversification of sexual traits in Bibionidae and other Diptera.

AbstractDeep learning offers a promising pathway for automated species recognition, yet model generalizability is often constrained by image datasets that lack multi-angle views of specimens. Using four tephritid species as a model system, we quantitatively evaluate how specimen imaging angles affect classification performance. Multi-angle imaging substantially improved model generalization even with fewer specimens, and greater angular diversity required substantially fewer specimens to achieve comparable performance—though this advantage diminished under extreme scarcity. Stronger data augmentation and extended training epochs could not compensate for limited angular diversity, whereas selecting appropriate architectures partially mitigated this limitation: lightweight convolutional neural networks sufficed for small species sets, while transformers became increasingly advantageous as taxonomic diversity grew. These patterns held when scaling to a larger dataset of 26 tephritid species, confirming the generalizability of our findings. Together, this study demonstrates that angular diversity provides irreplaceable information for model generalization, a benefit that in silico alternatives cannot replicate. This work provides a quantitative, resource-efficient framework for artificial intelligence-assisted insect identification, offering practical guidance for dataset construction in quarantine surveillance, biodiversity monitoring and taxonomic research.

The nemourid genera Indonemoura and Nemoura are recorded for the first time from Chongqing Municipality in southwestern China. We illustrate five nemourid species with colour photographs, including Indonemoura yintiaolinga sp. n., and four species newly recorded from Chongqing, and establish a new synonymy: Amphinemura annulata Du and Ji Amphinemura unihamata (Wu). The new species is compared with related congeners.http://www.zoobank.org/urn:lsid:zoobank.org:pub:09E1DA80-8086-4758-A798-9856E8141D29

The article describes four new species of Amphinemura Ris, 1902 from China, namely Amphinemura hystrix Wang, Wang and Li sp. nov., Amphinemura hanma Wang, Wang and Li sp. nov., Amphinemura jinfoshan Wang, Wang and Li sp. nov. and Amphinemura qinba Wang, Wang and Li sp. nov.. All species are described based on male and female specimens, compared with similar taxa, and illustrated with detailed descriptions and photographs.

A new species of crane fly, Tipula (Pterelachisus) jingkei sp. nov., is described from Beijing, China. The new species is distinguished from related species by the characteristic wing pattern and the structure of the male hypopygium, particularly the nearly truncate caudal margin of tergite 9 bearing two spinous median extensions and a small median spur. Illustrations and detailed morphological descriptions of the adult are provided. This species represents the first record of the subgenus Pterelachisus from Beijing and expands the known diversity of the group in northern China.

Background The adaptation of aquatic insects to freshwater habitats is a key question for understanding insect evolution. Many aquatic insects undergo significant morphological and physiological changes during the aquatic-terrestrial life-style transition. However, changes of internal anatomical structures and organs with the process of transformation have yet to be comprehensively investigated. Results Here we document the anatomical transformations of the skeletal-muscular system, nervous system, digestive system, and tracheal system during the aquatic-terrestrial life-style transition in an aquatic insect species Protohermes xanthodes Navás, 1914 (Megaloptera: Corydalidae), using micro-CT and 3D reconstruction. Notably, unlike the rapid, concentrated breakdown of other organ systems, the tracheal system undergoes a prolonged, stepwise, and tightly orchestrated disintegration‑reconstruction process during the major developmental stages. The digestive system is markedly modified but without complete disintegration across these stages. For predation and sensation under water, the larvae possess powerful mandibles and prothoracic muscles, and short but well-developed antennal nerves. In addition, the well-developed mesothoracic, metathoracic, and abdominal muscles at the filament base of the larvae enable underwater swimming. Conclusions This study provides new insights into the dynamic adaptations during the aquatic-terrestrial transition in insects and sheds light on coordinated evolution across multiple functional systems in response to environmental pressures.

Environmental DNA (eDNA) serves as the material foundation for biodiversity research. As a revolutionary biomonitoring tool, eDNA technology offers significant advantages such as being non-invasive, efficient, and cost-effective. Understanding the eDNA research landscape in China is important for global scholars, both for tracking progress in this field and for observing how an advanced biodiversity monitoring technology is systematically validated and applied in a major biodiversity-rich country. This study employs the CiteSpace bibliometric analysis tool, based on 304 publications from the CNKI database, to systematically map the research landscape in this field. The results indicate a consistent upward trend in the number of publications within China’s eDNA research domain, which has evolved through three stages. The field involves numerous researchers, with the top three prolific authors being Xiao-wei Zhang, Jiang-hua Yang, and Zhi Chen. Some research institutions have formed clusters, but a close cross-institutional collaborative network has yet to be established. Chinese eDNA research is oriented toward technological application and addressing ecological issues, with current hotspots focusing on applying eDNA technology to biodiversity studies through biomonitoring, biomass assessment, and biological community structure analysis, targeting phytoplankton, benthic animals, fish, and environmental microorganisms, among others. However, it also faces common global challenges. This study provides a reference for environmental DNA-related research and contributes Chinese experience and insights to global biodiversity monitoring.

ABSTRACT Due to climate change damaging terrestrial ecosystems and threatening biodiversity, the conservation of cave‐endemic lineage has garnered growing attention, as they serve as unique model systems for studying climate sensitivity, distributional constraints, and extinction risk. Given the limited research on endemic species, this study aims to identify the limiting factors, distribution range, and future changes in suitable habitats for the endemic species Bisetocreagris, thereby providing a scientific basis for the conservation of cave ecosystems. We used 44 distribution points and a MaxEnt model to predict Bisetocreagris distribution, integrating seven environmental variables and three emission scenarios to assess climate‐driven habitat changes. The results indicate that factors such as Bio14, Bio2, and Bio7 collectively characterize the dependence of cave‐endemic lineages on stable microenvironments and the potential limits of their physiological tolerance, reflecting the niche specialization that has evolved in the genus Bisetocreagris during its long‐term adaptation to cave environments. Under current climate conditions, Bisetocreagris has a highly suitable growth area of 97.1877 × 104 km2, which is primarily concentrated in southeastern China, with the widest distribution in Guizhou Province. Under various carbon emission scenarios, the potential suitable area consistently decreases. The high‐carbon‐emission SSP5–8.5 pathway has the most significant impact on high‐suitability area, resulting in a 97.8808% reduction by the 2090s compared to the present, leaving an area of only 2.0596 × 104 km2. The narrow distribution ranges, specialized ecological niches, and limited dispersal capacity observed in Bisetocreagris are traits shared by many arachnids. The response patterns revealed in this study may therefore extend beyond the focal genus to reflect broader vulnerabilities within the class Arachnida. Consequently, this research not only provides a scientific basis for habitat conservation and priority area identification for Bisetocreagris but also offers a transferable framework for assessing climate change vulnerability across other arachnids.

Accurate and rapid identification of quarantine-significant tephritids is critical to global agricultural biosecurity, but the application of deep learning is limited by the lack of large public image datasets. We present Tephritid26, a multi-angle image dataset of 26 tephritid species to address this gap. The dataset includes 38,081 images from 1,473 specimens across seven genera and two subfamilies, assembled through a global collaborative effort to source these regulated species. Specimens were mounted using a novel protocol combining varied thoracic attachment points and pin angles, and a rotational imaging setup then systematically captured each specimen from multiple perspectives to mimic real inspection conditions. The dataset is formatted for machine learning workflows. To demonstrate its utility, we trained deep learning models for species identification. ResNet-50, ConvNeXt-B, Vit-Small and Swin-Tiny all attained high species-level accuracy (Macro-Averaged F1-score > 96.75). Gradient-weighted Class Activation Mapping confirmed that the models focused on taxonomically informative morphological regions. This dataset serves as a benchmark for developing automated identification tools in phytosanitary applications.

Previously, nine species of the genus Dasymallomyia Brunetti, 1911 were known worldwide, of which three were known from China: D. clausa Alexander, 1940, D. persignata Alexander, 1932 and D. signata Brunetti, 1911. Here, the following four new species of this genus are described from China: D. bifurcata sp. nov., D. curvispina sp. nov., D. dentata sp. nov. and D. immaculata sp. nov. A key to the world species of Dasymallomyia is presented.

The 14 species of Coproica Rondani now known from China are reviewed and keyed, including two new species (C. spiculata sp. nov. and C. tapera sp. nov.), and one newly recorded species (Coproica thaii Papp, 2008).

Freshwater biodiversity underpins ecosystem functioning and human well-being. As the most diverse taxonomic groups in freshwater ecosystems, benthic invertebrates are widely employed as bioindicators for aquatic monitoring and health assessment. In this study, environmental DNA (eDNA) metabarcoding was used to reveal the diversity and spatiotemporal variations in benthic invertebrates in the Hun River Basin (the middle and upper reaches). Sampling was conducted in spring, summer, and autumn, with sites arranged to cover both anthropogenic activities and watershed environmental conditions. A total of 3 phyla, 7 classes, 18 orders, 56 families, 114 genera, and 161 species were detected. Insecta was the predominant class, and the combined EPT taxa (Ephemeroptera, Plecoptera, and Trichoptera) along with Diptera accounted for 64.71%, 74.18%, and 68.75% of the total taxa in spring, summer, and autumn. Community composition exhibited variations across both seasonal and spatial scales, as reflected by differences in OTU richness, dominant taxa and their relative sequence abundances, and alpha diversity indices. The top 10 dominant genera were all regionally common taxa, among which seven belonged to Insecta (including four from Chironomidae), whereas Sulcospira was the most spatially widespread dominant genus. Alpha and beta diversity analyses revealed significant seasonal differentiation but no significant spatial structuring. The SIMPER analysis identified the key genera that contributed substantially to observed community dissimilarity among sampling groups. This study provides fundamental data for freshwater biodiversity conservation and validates the potential applicability of eDNA metabarcoding for benthic invertebrate monitoring, while also revealing the current limitations of this technique.

Urbanization can act as a powerful ecological filter, restructuring biodiversity through species loss, replacement, and altered resource pathways. While urban green spaces (UGS) are recognized as potential biodiversity refuges, the effectiveness and mechanisms for conserving insect diversity across the urban-to-natural gradient remain poorly understood. Here, we combine full-season Malaise trapping (April–November) with MinION-based DNA barcoding to test two predictions about how urbanization reshapes Diptera communities across five sites in Haidian District, Beijing, ranging from residential areas and urban parks to a nearby shallow mountain reserve (BWM). Based on 5528 barcoded individuals, we identified 686 putative species from 39 families. As predicted, β-diversity between urban and mountain sites was overwhelmingly driven by species turnover rather than nestedness, demonstrating that cities do not simply receive subsets of the surrounding fauna but actively reassemble communities. This filtering effect was, however, trophic-guild specific. Detritivores showed the highest replacement, consistent with a shift from natural to anthropogenic resource subsidies, while predators/parasitoids exhibited significant nested loss, aligning with their hypothesized sensitivity at higher trophic levels. Vegetation structure further clarified these patterns: vegetation density, not plant species richness, was the primary bottom-up driver for herbivore and predator/parasitoid diversity, whereas detritivores were decoupled from living plant biomass. These findings demonstrate that urban and near-natural habitats maintain distinct species pools via guild-specific assembly pathways, highlighting the need for guild-specific conservation strategies for urban biodiversity conservation. Extending beyond compositional analysis, we propose a temporal-abundance framework, classifying species by persistence and abundance, as a diagnostic tool for assessing ecological integrity and guiding conservation in urbanizing landscapes.

Abstract Mosquitoes rank among the most deadly organisms worldwide, facilitating >700,000 human deaths annually through transmission of vector-borne pathogens. Culex are famous as vectors of multiple pathogens affecting both animals and humans. This study presents the first mitogenome sequencing and comparative analysis of seven species within Culex. Our findings demonstrated conserved structural features and nucleotide composition across the mitogenomes of these species. This study performed phylogenetic analysis of Culex based on mitochondrial genome data under both homogeneous and heterogeneous models separately, and estimated the divergence times. Phylogenetic analyses revealed that Culex is paraphyletic, with Lutzia nested within it. Both Cx. (Neoculex) and Cx. (Culex) were non-monophyletic. The two species of Cx. (Neoculex) were placed in separate lineages, with Cx. fergusoni as the sister group to all other Culex. Meanwhile, Cx. (Culex) was rendered paraphyletic by the inclusion of Cx. (Culiciomyia) and Cx. (Oculeomyia) within its clade. Divergence time estimation placed the basal split of Culicidae in Late Triassic, followed by the Culicinae-Anophelinae divergence in Late Jurassic (~147 Mya), with all speciation events within Culex postdating these splits and clustering in Neogene. This study provides a fundamental basis for understanding the mitogenomic architecture and phylogenetic relationships within the genus Culex, and also establishes a theoretical foundation for transmission mechanisms and control strategies of common mosquito-borne diseases.

The Amphinemura sinensis species group is distributed in China and Vietnam and is characterized by the horn-shaped lateral processes of the dorsal sclerite and the pointed ventral sclerite of the male epiproct. Species in the group are often difficult to distinguish because of their similar morphology and the limited number of reliable diagnostic characters. In this study, we examined the A. sinensis species using morphological and molecular data. COI sequences were obtained for 16 of the 34 recognized species, including the four new species described herein. Detailed examination of male genital structures and comparisons with previously described species support the recognition of four new species. The four new species are described and illustrated. With these additions, the A. sinensis species group now comprises 34 species.

The superfamily Nemouroidea (Plecoptera) represents one of the most diverse and ecologically significant groups of stoneflies, with nymphs serving as crucial bioindicators of freshwater ecosystem health due to their sensitivity to water quality. However, the evolutionary and genomic studies of this group have been hindered by the lack of high-quality reference genomes. Here, we present a chromosome-level genome assembly for Rhopalopsole triangulispina Mo and Li, 2025 within Nemouroidea, generated by integrating PacBio HiFi long reads, Illumina short reads, and Hi-C chromatin interaction data. The final assembly spans 347.119 Mb with a scaffold N50 of 27.479 Mb, and 96.91% (336.39 Mb) of the genome is anchored to 13 pseudochromosomes. BUSCO assessment reveals a high completeness of 98.4% (insecta_odb10). The genome contains 48.50% repetitive elements (168.35 Mb) and encodes 12,857 protein-coding genes, which were comprehensively annotated using homology, transcriptomic, and ab initio evidence. This high-quality genome provides a foundational resource for resolving phylogenetic relationships within Nemouroidea, advancing studies on insect genome evolution, and enhancing freshwater biomonitoring efforts through genomic tools.