(1) Background: The three sloe bugs, Dolycoris baccarum, Dolycoris indicus, and Dolycoris penicillatus, 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 Dolycoris 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 Dolycoris species identified based on morphological characters. A clear-cut barcode gap was discovered between the interspecific and intraspecific genetic distances of the three Dolycoris species. Phylogenetic analyses strongly supported the monophyly of Dolycoris, with interspecific relationship inferred as (D. indicus + (D. baccarum + D. penicillatus)); (4) Conclusions: Our study provides the first insight into the species boundaries and phylogenetic relationships of the three Dolycoris species distributed across the Chinese mainland.

The mitochondrial genome (mitogenome) has been widely used for structural comparisons and phylogenetic analyses of Hemiptera groups at different taxonomic levels. However, little is known about the mitogenomic characteristics of species from Antheminia and Carpocoris, two morphologically similar genera in the Pentatomidae family, and their phylogenetic relationships need to be further confirmed. In this study, the mitogenomes of Antheminia varicornis (Jakovlev, 1874) and Carpocoris purpureipennis (De Geer, 1773) were sequenced and analyzed. Coupled with previously published mitogenomes of Pentatomidae, we performed a phylogenetic analysis. The mitogenomes of A. varicornis and C. purpureipennis are conserved in terms of genomic structure, base composition, codon usage, and tRNA secondary structure. Each mitogenome contains the typical 37 genes and a control region and all genes are arranged in the same order as in the ancestral insect mitogenome. Nucleotide composition is highly biased with the third codon in PCGs displaying the highest A + T content. Phylogenetic analysis strongly supports the sister relationship between A. varicornis and C. purpureipennis. The phylogenetic trees show a strong support for the monophyly of Asopinae and Phyllocephalinae, while the monophyly of Pentatominae and Podopinae was rejected. Our study enriches the mitochondrial genome database of the genera Antheminia and Carpocoris and provides a valuable resource for further phylogenetic and evolutionary analyses of the Pentatomidae.

(1) Background: The identification of Tropidothorax cruciger and T. sinensis is often complicated by the presence of the “intermediate form”. Due to the lack of molecular data, the taxonomic status of the “intermediate form” and the species boundaries between T. cruciger and T. sinensis remain uncertain; (2) Methods: In this study, we integrated morphological, molecular, and ecological data to delimit species boundaries of these two species using multiple species delimitation approaches; (3) Results: Most species delimitation analyses based on the cytochrome c oxidase subunit I (COI) fragment suggested that T. cruciger and the “intermediate form” comprised a single species, with T. sinensis representing a separate species. This delimitation result was also supported by the analyses of BFD* and genetic clustering based on genome-wide SNPs. Under this species delimitation scenario, a clear-cut barcode gap was discovered between the interspecific and intraspecific genetic distances. In addition, environmental-related analyses showed highly similar ecological requirements of T. cruciger and the “intermediate form”, supporting their recognition as a single species; (4) Conclusions: This study clarifies the taxonomic status of the “intermediate form” and the species boundaries between T. cruciger and T. sinensis, which is essential for further studies of ecology and evolution of these species.