Cladistics of South American Triatoma (Hemiptera: Reduviidae): a morphological overview of T. infestans complex

BACKGROUND Triatoma infestans complex comprises 39 species of South American triatomines, organised into different subcomplexes. These species act as vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. However, the evolutionary relationships among the subcomplexes remain unresolved. OBJECTIVES In this study, we present the most comprehensive morphological cladistic analysis of these species to date. METHODS Phylogenetic relationships were examined in a new analysis based on morphological data. We analysed a data matrix comprising 48 terminal taxa and 72 morphological characters, coded under implicit parsimony weights, with a range of concavities (k1-80). FINDINGS Our results indicate that the T. infestans and Triatoma rubrovaria subcomplexes constitute monophyletic groups, while Triatoma brasiliensis, Triatoma matogrossensis and Triatoma sordida subcomplexes are merophyletic. We also confirm that Triatoma maculata does not belong to the homonymous subcomplex. MAIN CONCLUSIONS The study presents the first cladistic analysis and provides a solid foundation for understanding phylogenetic relationships within of the T. infestans complex.