DNA barcoding for biodiversity assessment: Croatian stoneflies (Insecta: Plecoptera)

Species Delimitation and Cryptic Diversity in Rheotanytarsus Thienemann & Bause, 1913 (Diptera: Chironomidae) Based on DNA Barcoding

The genus Rheotanytarsus Thienemann & Bause, 1913 (Diptera: Chironomidae) currently includes more than 120 recognized species worldwide, but precise species-level identification based solely on morphology remains challenging. Pronounced morphological differences among life stages and the time-consuming inefficiency of rearing larvae further complicate life-stage matching in this genus. In this study, we assessed species diversity by integrating morphological examination and DNA barcoding, analyzing 911 DNA barcodes from newly collected samples and a public database. Based on these results, we further constructed a relatively complete life-history framework. Our results show that 911 Rheotanytarsus DNA barcodes belong to 69 putative species. The maximum intraspecific divergence reached 7.35% in R. pentapoda, and the average minimal interspecific distance was 11.44%. Substantial intraspecific divergence in certain species complexes suggests the presence of cryptic species. Therefore, to resolve these potential cryptic species issues, more extensive sampling and morphological examination of specimens from geographically distant regions-supplemented by nuclear and ecological data-are required.

Gone with Water or Mountain: The Population Genetic Diversity of Rhopalopsole sinensis Yang and Yang, 1993 in China

Rhopalopsole sinensis Yang and Yang, 1993 is one of the most widely distributed stoneflies in southern China. In this study, the genetic structure of nine different geographical populations of R. sinensis was studied based on three datasets of the 18S, COI and ITS2 genes. The phylogenetic trees showed that there had been a great degree of genetic differentiation among its nine geographical populations, but the hypothesis of random mating did not support the formation of reproductive isolation among different geographical populations, indicating that R. sinensis did not form cryptic species. The establishment of the 18S gene and ITS2 gene supports the population of (Guangdong + Shaanxi + Sichuan + Guizhou + Fujian) as independent branches, while the population of (Anhui + Zhejiang + Hunan) is another branch. The establishment of COI gene tree supports (Shaanxi + Sichuan + Guizhou + Fujian) as one branch, while the other independent branch is composed of (Anhui + Zhejiang + Guangxi + Hunan + Guangdong) groups. The possible reasons for this situation based on geography and biology are discussed. Our results provide the first reference for the genetic differentiation in Chinese Rhopalopsole stoneflies.

Data on insect biodiversity in a Chinese potato agroecosystem from DNA metabarcoding

Potato (Solanum tuberosum) is a staple crop important in global food security. As a leading potato producer, China faces significant challenges from insect pest infestations that compromise yield and quality. However, insect communities within Chinese potato fields remain poorly characterized. This study aimed to explore insect diversity in potato fields in Yunnan Province. From autumn 2021 to summer 2022, five Malaise traps were strategically deployed to capture insect samples. In total, 245 samples were collected over 49 weeks, and DNA metabarcoding was performed on bulk samples. The generated sequences were curated and analyzed using the Barcode of Life Data System and the Multiplex Barcode Research and Visualization Environment. The analysis assigned sequences to 1,688 Barcode Index Numbers (BINs) as species proxies derived from the Global Insecta Library, along with 166 BINs from the China Insecta dataset. This research provides valuable insights for barcoding local biodiversity and developing regional reference libraries and presents a comprehensive dataset of insect biodiversity within potato agroecosystems, encompassing 1,707 BINs linked to known insect taxa.

Overview of the Caucasian Perla Geoffroy, 1762 (Plecoptera: Perlidae) based on morphological and molecular data with description of two new species

Six species of Caucasian Perla are reviewed, and diagnostic morphological characteristics of all stages of development (where possible) are described, supplemented, and illustrated in detail with comparative light microscope and scanning electron microscopy images. The DNA barcoding of five species is presented. Two new morphologically and genetically distinct species, Perla schapsugica sp. nov. and Perla palatovi sp. nov., are described for both sexes and all life stages in the North Caucasus, Russia, Krasnodar Kray. Reinstatement of Perla persica Zwick, 1975, as a valid species distinct from P. caucasica Guérin-Méneville, 1843, is proposed. A new record of P. persica is reported for the Greater Caucasus, Russia, North-Ossetia-Alania for the first time. Morphologically, these two latter species can be separated in male adults by the shape of the hemitergal hook on terga X, an additional ventral brush on the penis of P. caucasica, wing length, and color.

Detailed DNA barcoding of mayflies in a small European country proved how far we are from having comprehensive barcode reference libraries

Mayflies (Ephemeroptera) are among the crucial water and habitat quality bioindicators. However, despite their intensive long-term use in various studies, more reliable mayfly DNA barcode data have been produced in a negligible number of countries, and only ~40% of European species had been barcoded with less than 50% of families covered. Despite being carried out in a small area, our study presents the second-most species-rich DNA reference library of mayflies from Europe and the first comprehensive view from an important biodiversity hotspot such as the Western Carpathians. Within 1153 sequences, 76 morphologically determined species were recorded and added to the Barcode of Life Data System (BOLD) database. All obtained sequences were assigned to 97 BINs, 11 of which were unique and three represented species never barcoded before. Sequences of 16 species with high intraspecific variability were divided into 40 BINs, confirming the presence of cryptic lineages. Due to the low interspecific divergence and the non-existing barcoding gap, sequences of six species were assigned to three shared BINs. Delimitation analyses resulted in 79 and 107 putative species respectively. Bayesian and maximum-likelihood phylogenies confirmed the monophyly of almost all species and complexes of cryptic taxa and proved that DNA barcoding distinguishes almost all studied mayfly species. We have shown that it is still sufficient to thoroughly investigate the fauna of a small but geographically important area to enrich global databases greatly. In particular, the insights gained here transcend the local context and may have broader implications for advancing barcoding efforts.

Assessing arthropod biodiversity with DNA barcoding in Jinnah Garden, Lahore, Pakistan

Previous difficulties in arthropod taxonomy (such as limitations in conventional morphological approaches, the possibility of cryptic species and a shortage of knowledgeable taxonomists) has been overcome by the powerful tool of DNA barcoding. This study presents a thorough analysis of DNA barcoding in regards to Pakistani arthropods, which were collected from Lahore's Jinnah Garden. The 88 % (9,451) of the 10,792 specimens that were examined were able to generate DNA barcodes and 83% (8,974) of specimens were assigned 1,361 barcode index numbers (BINs). However, the success rate differed significantly between the orders of arthropods, from 77% for Thysanoptera to an astounding 93% for Diptera. Through morphological exams, DNA barcoding, and cross-referencing with the Barcode of Life Data system (BOLD), the Barcode Index Numbers (BINs) were assigned with a high degree of accuracy, both at the order (100%) and family (98%) levels. Though, identifications at the genus (37%) and species (15%) levels showed room for improvement. This underscores the ongoing need for enhancing and expanding the DNA barcode reference library. This study identified 324 genera and 191 species, underscoring the advantages of DNA barcoding over traditional morphological identification methods. Among the 17 arthropod orders identified, Coleoptera, Diptera, Hemiptera, Hymenoptera, and Lepidoptera from the class Insecta dominated, collectively constituting 94% of BINs. Expected malaise trap Arthropod fauna in Jinnah Garden could contain approximately 2,785 BINs according to Preston log-normal species distribution, yet the Chao-1 Index predicts 2,389.74 BINs. The Simpson Index of Diversity (1-D) is 0.989, signaling high species diversity, while the Shannon Index is 5.77, indicating significant species richness and evenness. These results demonstrated that in Pakistani arthropods, DNA barcoding and BOLD are an invaluable tool for improving taxonomic understanding and biodiversity assessment, opening the door for further eDNA and metabarcoding research.

Utilising public sequence databases to investigate genetic diversity of stoneflies in Medvednica Nature Park

In Medvednica Nature Park, near Croatia's capital Zagreb, urbanisation significantly impacts the fauna. Comprehensive field research has never been conducted in this area, despite the presence of diverse microhabitats and the discovery of several rare species previously unknown in the Croatian fauna. This study provides the Park with first insight into the genetic and morphological diversity of stoneflies, one of the most endangered groups of organisms. Phylogenetic reconstructions and species delineation methods revealed intraspecific haplotype variation in most species (e.g. Brachypteraseticornis, Isoperlagrammatica and Leuctrabraueri), except for Leuctraprima. Additionally, our study has identified isolated populations that merit further in-depth investigation concerning morphology, genetics and ecology.

A comprehensive DNA barcoding reference database for Plecoptera of Switzerland

DNA barcoding is an essential tool in modern biodiversity sciences. Despite considerable work to barcode the tree of life, many groups, including insects, remain partially or totally unreferenced, preventing barcoding from reaching its full potential. Aquatic insects, especially the three orders Ephemeroptera, Plecoptera, and Trichoptera (EPT), are key freshwater quality indicators worldwide. Among them, Plecoptera (stoneflies), which are among the most sensitive aquatic insects to habitat modification, play a central role in river monitoring surveys. Here, we present an update of the Plecoptera reference database for (meta)barcoding in Switzerland, now covering all 118 species known from this country. Fresh specimens, mostly from rare or localized species, were collected, and 151 new CO1 barcodes were generated. These were merged with the 422 previously published sequences, resulting in a dataset of 573 barcoded specimens. Our CO1 dataset was delimited in 115 CO1 clusters based on a priori morphological identifications, of which 17% are newly reported for Switzerland, and 4% are newly reported globally. Among the 115 CO1 clusters, 85% showed complete congruence with morphology. Distance-based analysis indicated local barcoding gaps in 97% of the CO1 clusters. This study significantly improves the Swiss reference database for stoneflies, enhancing future species identification accuracy and biodiversity monitoring. Additionally, this work reveals cryptic diversity and incongruence between morphology and barcodes, both presenting valuable opportunities for future integrative taxonomic studies. Voucher specimens, DNA extractions and reference barcodes are available for future developments, including metabarcoding and environmental DNA surveys.