Mitogenomes Provide Insights into the Species Boundaries and Phylogenetic Relationships among Three Dolycoris Sloe Bugs (Hemiptera: Pentatomidae) from China

(1) Background: The three sloe bugs, , and , are found in the Chinese mainland and are morphologically similar. The species boundaries and phylogenetic relationships of the three species remain uncertain; (2) Methods: In this study, we generated multiple mitochondrial genomes (mitogenomes) for each of the three species and conducted comparative mitogenomic analysis, species delimitation, and phylogenetic analysis based on these data; (3) Results: Mitogenomes of the three species are conserved in nucleotide composition, gene arrangement, and codon usage. All protein-coding genes (PCGs) were found to be under purifying selection, and the ND4 evolved at the fastest rate. Most species delimitation analyses based on the COI gene and the concatenated 13 PCGs retrieved three operational taxonomic units (OTUs), which corresponded well with the three species identified based on morphological characters. A clear-cut barcode gap was discovered between the interspecific and intraspecific genetic distances of the three species. Phylogenetic analyses strongly supported the monophyly of , with interspecific relationship inferred as ( + ( + )); (4) Conclusions: Our study provides the first insight into the species boundaries and phylogenetic relationships of the three species distributed across the Chinese mainland.