Mitogenomes of three Sinoxylon species and the phylogenetic analysis of Bostrichoidea   (Coleoptera)
The family Bostrichidae is a well-known pest of agriculture, forest, and quarantine. In this study, we employed next-generation sequencing (NGS) to sequence the complete mitochondrial (mt) genomes of three Bostrichidae species, i.e., Sinoxylon japonicum, S. pygmaeum, and S. flabrarius. Comparative mitochondrial genomic analysis revealed that the mitogenomes of these species ranged from 15,543 to 16,009 bp, containing 37 genes (13 protein-coding genes, 22 transfer RNAs, and two ribosomal RNAs) and a control region. The gene order and content are consistent with the conserved mitogenomic architecture of Coleoptera. Notably, distinct variations were identified in the start codons of two PCGs (COX1 and ND6) and the stop codon of CYTB across the three species. Phylogenetic analyses based on maximum likelihood (ML) and Bayesian inference (BI) methods provide robust support for the monophyly of the subfamily Bostrichinae and establish Bostrichidae as the sister group to Ptinidae, Dermestidae, and Nosodendridae. Our findings elucidate the genomic characteristics of Bostrichidae and reconstruct the evolutionary relationships within this taxon, offering a foundational reference for future taxonomic and phylogenetic studies in the family.