Background: Acanthosomatidae (Hemiptera: Pentatomoidea), commonly known as parent bugs, is a comparatively small pentatomoid family whose biological distinctiveness is exemplified by the repeated evolution of maternal egg–nymph guarding in several lineages; however, mitogenomic data for this group remain limited. Acanthosoma murreeanum is an important representative of Acanthosoma, yet its complete mitochondrial genome and comparative mitogenomic characteristics have not been comprehensively studied. Methods: Here, we obtained the complete mitochondrial genome of A. murreeanum through sequencing, assembly, and annotation. We then characterized its mitogenomic structure, nucleotide composition, codon usage, RNA structural features, control-region organization, nucleotide diversity, evolutionary rates, and phylogenetic position. In addition, control-region characteristics were compared among available acanthosomatid mitogenomes to evaluate structural variation in the AT-rich region. Results: The sequenced mitochondrial genome of A. murreeanum is a circular molecule of 15,718 bp, comprising the standard set of 37 mitochondrial genes and a control region of 1104 bp. The genome exhibits a strong A + T bias (74.04%) and retains the typical mitochondrial gene order without gene rearrangement. Most protein-coding genes start with standard ATN codons, except COX1, which begins with TTG, whereas COX2 and ND5 terminate with incomplete stop codons. Most predicted tRNA genes displayed the conventional cloverleaf configuration, whereas trnS1 lacked a complete DHU arm and instead formed a simple loop. The control region was characterized by a 60 bp tandem-repeat unit and several conserved sequence motifs. Comparative analysis showed that control-region length, AT content, repeat-unit size, and motif composition varied among sampled Acanthosomatidae, while A. murreeanum and A. haemorrhoidale shared similar 60 bp tandem-repeat organization. Among the mitochondrial PCGs, ATP8 exhibited the highest level of variation, whereas COX1 was the most conserved. The Ka/Ks values of all genes were lower than 1, suggesting that these genes have evolved under purifying selection. Phylogenetic analyses based on maximum-likelihood and Bayesian-inference methods consistently supported a sister relationship between A. murreeanum and A. haemorrhoidale. Conclusions: This study provides a new mitogenomic resource for Acanthosomatidae and represents the first detailed comparative mitogenomic analysis within Acanthosoma. The results suggest that A. murreeanum retains a conserved mitochondrial genomic architecture, whereas variation in the AT-rich control region provides additional evidence for lineage-specific mitogenomic differentiation. These results provide useful insights into mitogenome evolution and phylogenetic relationships within Acanthosoma and closely related acanthosomatid groups.
Ye et al. (Sat,) studied this question.