(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.

Ishikawaella is an obligate gut bacterium in stinkbugs that belong to Plataspidae family (Hemiptera: Heteroptera). It is vertically transmitted to newborn nymphs through capsules laid on eggs by maternal stinkbugs. Previous research has established a pattern of strict cospeciation between Plataspidae stinkbugs and Ishikawaella . However, the possibility of host–symbiont coevolution at the population level within Plataspidae stinkbugs has not been thoroughly explored. This study analyzed the samples of Megacopta cribraria from three phylogenetic clades to investigate host–symbiont coevolution in this insect species. We compared data from third‐generation sequencing (PacBio), next‐generation sequencing (Illumina), and first‐generation sequencing (Sanger), and the results indicated that Illumina sequencing most accurately represents the composition of gut bacterial communities. All stinkbug individuals shared a dominant amplicon sequence variant (ASV), which accounted for an average of 65.99% of Ishikawaella sequences (ranging from 58.68% to 87.01%). The top five ASVs (ASV0–ASV4) represented 99.82% of all Ishikawaella sequences. Among these, the number of base substitutions between any two ASVs ranged from 1 to 3, significantly lower than the number of substitutions between the main and minor ASVs. This finding suggests that closely related strains are likely to coexist in the same host. Beta diversity analyses revealed significant differences in Ishikawaella composition among the three phylogenetic clades, providing evidence for host–symbiont coevolution at the population level in Plataspidae stinkbugs.

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.

Rice (Oryza sativa) provides a major food resource worldwide, playing an important role in the global economy. Leptocorisa acuta (Hemiptera: Alydidae), commonly known as the rice seed bug, is a major pest of paddy crops in many rice-growing regions and it is considered a potential invasive pest in the United States. Here, we investigated the genetic structure and demographic history of 18 populations sampled from China and southeast Asia using double-digest restriction site-associated DNA sequencing (ddRAD-seq). Then, we performed niche modeling based on occurrence records under current and future climate scenarios. Our analyses suggested that the lack of genetic structure among populations of L. acuta is related to recent diversification, strong flight, and dispersal capability, leading to a high level of gene flow. The demographic history was not strongly affected by the last glacial maximum. Ecological niche modeling predicts that future suitable areas will expand in Asia and America, relative to the current conditions. The ecological niche results demonstrated that L. acuta is a potentially invasive pest to the United States (mainly Florida and nearby areas) under current and future scenarios. Moreover, the moderately and highly suitable areas will increase in America (primarily located in North America, namely Florida and nearby areas, and Mexico), Central American and Caribbean countries, and some regions of South America. Some South American countries have extensive rice crops and broadly suitable habitats that may indicate a higher invasion risk. Through population genetics, our study supports the strong dispersal capacity of this insect pest and calls for vigilance against its invasion in some countries in the Americas.