(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 flower bugs genus Anthocoris consists of small predatory insects with 2 major species groups, the A. nemorum group and the A. thibetanus group, are predominantly found in the high-altitude regions of the Qinghai–Tibet Plateau (QTP) and its surrounding mountains. Their small size and subtle morphological differences make it difficult to delimit species using only morphological characteristics, and no molecular studies have yet assessed whether the diversification of these groups was driven by the same period of plateau uplift. To address these challenges, this study employs comprehensive delimitation methods, including morphological analysis and single-locus and multilocus analyses, to classify species within the A. nemorum and A. thibetanus groups. Six new species are described: A. neomontanus Tang & Bu, sp. nov., A. neonemorum Tang & Bu, sp. nov., A. renae Tang & Bu, sp. nov., A. kangdingensis Tang & Bu, sp. nov., A. fuae Tang & Bu, sp. nov., A. liui Tang & Bu, sp. nov. Four data sets with hundreds of loci but fewer individuals, BPP may serve as a suitable delimitation method. Combined with our analyses of examined gene tree discordance, and divergence time estimations, the repeated rapid uplifts of the QTP and surrounding mountains are likely the primary drivers of the complex reticulate evolutionary history of these two species groups. Our findings indicate that a BUSCO library at the order level, based on genome skimming, can provide a sufficient number of loci and has the potential for effective species delimitation in cases involving complex reticulate evolution.