We describeArge bellaWei & Du sp. nov., a large and beautiful species of Argidae from south China, and report its mitochondrial genome based on high-throughput sequencing data. We present the gene order, nucleotide composition of protein-coding genes (PCGs), and the secondary structures of RNA genes. The nearly complete mitochondrial genome ofA. bellahas a length of 15,576 bp and a typical set of 37 genes (22 tRNAs, 13 PCGs, and 2 rRNAs). Three tRNAs are rearranged in theA. bellamitochondrial genome as compared to the ancestral type in insects:trnMandtrnQare shuffled, whiletrnWis translocated from thetrnW-trnC-trnYcluster to a location downstream oftrnI. All PCGs are initiated by ATN codons, and terminated with TAA, TA or T as stop codons. All tRNAs have a typical cloverleaf secondary structure, except fortrnS1. H821 ofrrnSand H976 ofrrnLare redundant. A phylogenetic analysis based on mitochondrial genome sequences ofA. bella, 21 other symphytan species, two apocritan representatives, and four outgroup taxa supports the placement of Argidae as sister to the Pergidae within the symphytan superfamily Tenthredinoidea.

Accurate identification and precise classification of freshwater mussel species that are among the most threatened freshwater taxa in the world, play a crucial role in informing conservation and management efforts for these organisms. However, due to the variability in shell morphology, relying solely on shell characteristics for species taxonomy poses significant challenges, thereby impeding effective conservation planning and management. The freshwater mussel genus Ptychorhynchus Simpson, 1900 is one such group in need of study. We integrate molecular phylogeny, shell morphology and soft-body anatomy to examine the classification of Ptychorhynchus denserugata (Haas, 1910) and Ptychorhynchus resupinatus (von Martens, 1902). The COI barcoding data support the clustering of P. denserugata and Nodularia douglasiae within a single clade, and P. denserugata shares the diagnostic feature of the genus Nodularia, i.e. knobs or bumps on the inner mantle surface in the excurrent aperture. Therefore, by integrating molecular data and anatomical characteristics, we confirm that the nominal species P. denserugata syn. nov. is a new synonym for N. douglasiae. The multi-locus (COI + ND1 + 16S rRNA + 18S rRNA + 28S rRNA) phylogeny and mitochondrial phylogenomics support the transfer of P. resupinatus from Ptychorhynchus to the newly elevated genus Cosmopseudodon stat. rev., as Cosmopseudodon resupinatus stat. rev. that is still considered the designated type species. We also describe a new species based on integrative taxonomy, i.e. Cosmopseudodon wenshanensis sp. nov. The comprehensive understanding of the taxonomy and diversity of the revised Cosmopseudodon species, and shell heteromorphism of N. douglasiae (=P. denserugata syn. nov.), will serve as a crucial foundation for further scientific assessment and conservation strategies pertaining to these taxa. ZooBank: urn:lsid:zoobank.org:pub:E48968B1-DF0F-42AD-8F31-B8C95F23CE57

A new genus with a new species of the tribe Hoplocampini of Hoplocampinae was described from China:Analcellicampa xanthosomaWei & Niu,gen. et sp. nov.Hoplocampa danfengensisG. Xiao 1994 was designated as the type species of the new genus. The characters ofAnalcellicampa danfengensis(G. Xiao)comb. nov.were briefly discussed. A key to the tribes and known genera of Hoplocampinae was provided. The nearly complete mitochondrial genome ofA. xanthosomawas characterized as having a length of 15,512 bp and containing 37 genes (22 tRNAs, 13 protein-coding genes (PCGs), and 2 rRNAs). The gene order of this new specimen was the same as that in the inferred insect ancestral mitochondrial genome. All PCGs were initiated by ATN codons and ended with TAA or T stop codons. All tRNAs had a typical cloverleaf secondary structure, except fortrnS1. Remarkably, the helices H991 ofrrnSand H47 ofrrnLwere redundant, while helix H563 ofrrnLwas highly conserved. A phylogeny based on previously reported symphytan mitochondrial genomes showed thatA. xanthosomais a sister group toMonocellicampa pruni, with high support values. We suggest thatA. xanthosomaandM. prunibelong to the tribe Hoplocampini of Hoplocampinae.

Anhoplocampa is redescribed based on new material. Anhoplocampa bicoloricornis sp. n. from China is described. A. yunanensis (Haris & Roller, 1999) comb. n.

The systematic status of the genus Athalia and related genera is a perennial controversy in sawfly taxonomy. Several authors have hypothesized that the placement of Athalia within the Tenthredinidae is artificial, but no studies have focused on this topic. If the hypothesis that Athalia does not belong to Tenthredinidae can be supported, the taxonomic framework of Tenthredinoidea needs revision. We present a comprehensive phylogenomic study of Tenthredinoidae, focusing on the positions of Athalia and related genera by sampling 80 representatives mainly of the Tenthredinoidea, including Heptamelinae and Blasticotomidae. Our phylogenetic reconstructions based on nuclear genes and mitochondrial (mt) sequences support Athalia and related genera as a distinct clade sister to Tenthredinidae + (Cimbicidae + Diprionidae). A comparison of symphytan mitochondrial genomes reveals an innovative gene rearrangement pattern in Athaliidae, in which Dentathalia demonstrates a more ancestral pattern than Athalia and Hypsathalia. The lineage specificity of mt rRNA secondary structures also provides sufficient support to consider Athaliidae as a separate family. In summary, the phylogeny and genomic structural changes unanimously support the taxonomic treatment of Athaliidae as a family and the re-establishment of Dentathalia as a valid genus.