Reconstructing Sordida subcomplex (Hemiptera, Reduviidae, Triatominae) phylogeny across species distribution range

BACKGROUND The conformation of the Sordida subcomplex has been a topic of prolonged debate, with diverse methodological approaches employed to discern its constituent species. Up to now, Triatoma sordida, T. garciabesi and T. rosai comprise part of this subcomplex. Distinguishing and identifying these three species pose significant challenges due to their pronounced morphological similarity, overlapping distributions, and presence of natural hybrids. OBJECTIVES This study aims to uncover the genetic diversity and geographic spread of these three species. METHODS We analysed a mitochondrial cytochrome b gene fragment and complemented it with chromosomal studies across natural populations from an extensive geographical range, including Argentina, Bolivia, Brazil, and Paraguay. FINDINGS Phylogenetic analyses revealed genetic distances that suggest the presence of at least six putative species, rather than the three currently recognised. MAIN CONCLUSIONS The present findings underscore the potency and significance of molecular analyses from natural populations for species identification and highlight the limitations of morphology in classifying Triatominae species.