The quarantine pest, Opisina arenosella Walker, poses a significant threat to 34 palm plant species, including economically vital coconut trees. Its adaptability and rapid spread raise concerns about global tree invasion and potential economic and environmental impacts. Utilising advanced sequencing technology, this study aims to analyse O. arenosella mitochondrial genome, comparing it with three Lepidoptera families to explore its phylogenetic status. The complete mitochondrial genome (15,389 bp) was sequenced using the Illumina HiSeq platform, with tRNA genes validated using tRNAScan-SE and MITOS WebServer. Comparative analysis involved 13 protein-coding genes and 2 ribosomal RNA genes, comparing them with outgroup species like Agapanthia amurensis. The results revealed that O. arenosella genome’s nucleotide composition is 39.24% A, 41.33% T, 12.02% C, and 7.41% G. The phylogenetic tree was constructed using maximum likelihood (ML) and Bayesian inference (BI) methods. Interestingly, in the BI analysis, (O. arenosella + Ripeacma umbellate) clustered together with ((Promalactis suzukiella + Promalactis odaiensis) + (Stathmopoda auriferella + Casmara patrona)), forming a clade with high node support, while ML lacked high node support. Additionally, both methods indicated a monophyletic clade with high node support for Comparmustilia, Oberthueria, Pseudandraca, and Andraca. This research provides valuable mitochondrial genome data, contributing to phylogenetics and taxonomy studies, establishing a foundation for future research in this field.

The genus Bursaphelenchus has attracted significant attention due to its economically devastating and quarantined species – notably the pine wood nematode B. xylophilus and B. cocophilus. Despite their ecological and agricultural importance, genomic data for this genus remain scarce. In this study, we sequenced and assembled the complete mitochondrial genomes of three Bursaphelenchus species (B. chengi, B. parantoniae, and B. sinensis) using high-throughput sequencing. The circular mitogenomes exhibited size variation, with B. chengi (17,670 bp), B. parantoniae (15,021 bp), and B. sinensis (18,386 bp) each containing the typical nematode mitochondrial gene complement: 12 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, and 22 transfer RNA (tRNA) genes. Phylogenetic analysis based on the concatenated amino acid sequences of the 12 PCGs revealed that these species form a sister clade to B. xylophilus and B. mucronatus. Comparative mitogenomic analysis demonstrated a conserved gene arrangement shared among Bursaphelenchus, Aphelenchoides, Caenorhabditis, Cruznema tripartitum, and Pristionchus pacificus, suggesting strong evolutionary conservatism across the families Aphelenchoididae, Neodiplogasteridae, and Rhabditidae. Our study enriched the mitochondrial genomic resources for Bursaphelenchus and advanced resolution of their intrageneric phylogenetic relationships.

To clarify deep relationships among species lineages within Bacidia s. str., and to investigate the robustness of the deeper branches, we combined data from three traditionally used RNA-coding genes (nrITS, nrLSU and mtSSU) with two protein-coding genes (RPB1 and RPB2). The multigene phylogeny contained 48 newly generated sequences from the Russian Far East and all Bacidia s. str. sequences from GenBank (131 sequences). We subjected the alignments for the single and concatenated data sets to Bayesian inference (BI) and two maximum likelihood (ML) analyses (RAxML and IQ-TREE). The topologies of phylogenetic trees recovered from BI and ML analyses were highly concordant. The multilocus phylogeny of Bacidia s. str. was congruent with previous results based on nrITS sequences from the Russian Far East but with considerably higher support values for most of the deeper branches. A correlation between the recovered clades and apothecial pigments in the upper part of the hymenium and lateral exciple was observed. Based on morphological and molecular evidence, Bacidia obtecta is described as new to science. It was recovered as the sister lineage of B. elongata. The two species are alike in having up to four enlarged lumina cells along the exciple edge, but B. obtecta differs in the abundant crystals found in the upper hymenium and lateral exciple, and by having spores with fewer septa.