Mitochondrial genomes from RNA-Seq reveal phylogeny and selection in Mepraia (Hemiptera: Reduviidae).

Despite the epidemiological importance of triatomine bugs as vectors of Trypanosoma cruzi, mitogenomic resources remain limited for many lineages, restricting evolutionary and comparative analyses. The endemic Chilean genus Mepraia is a notable example, with scarce mitochondrial genomic information despite its relevance to Chagas disease ecology and vector evolution. Here, we reconstructed partial mitochondrial genomes, including all 13 protein-coding genes, from RNA-Seq data for three Mepraia species. Phylogenetic analyses confirmed the monophyly of Mepraia and resolved interspecific relationships, whereas comparative analyses revealed heterogeneous patterns of intraspecific diversity, with elevated variation in M. parapatrica. Codon-based tests detected pervasive purifying selection together with localized signals of positive selection in oxidative phosphorylation genes, particularly NAD5, NAD6, NAD1, and COIII. These results show that transcriptomic data provide a reliable source for mitochondrial genome reconstruction in non-model insects and that adaptive signals can coexist with strong functional constraint in triatomine mitogenomes. Overall, this study expands mitogenomic resources for Triatominae, improves evolutionary inference in Mepraia, and provides a foundation for future integrative studies on diversification, mitochondrial evolution, and vector biology.