Triatoma chiarii sp. nov. (Hemiptera, Reduviidae, Triatominae): a new species in the Triatoma brasiliensis complex from Rio Grande do Norte state, Brazil

Abstract Background A new triatomine species was discovered in the semiarid Caatinga region of Rio Grande do Norte, Brazil, where it coexists with Triatoma brasiliensis in both natural and artificial habitats. Methods Triatomine specimens were captured in peridomestic and sylvatic environments in Rio Grande do Norte. Their identification was based on a combination of analyses, including morphology using dichotomous keys, head and hemelytron morphometry, and phylogeny using cytochrome b and internal transcribed spacer markers. Results The new species exhibits morphological traits that are intermediate between those of Triatoma brasiliensis and Triatoma petrocchiae, but has distinct characteristics, leading to its designation as Triatoma chiarii sp. nov. Geometric morphometric analysis of its wings and head clearly distinguished T. chiarii sp. nov. from T. brasiliensis and T. petrocchiae, while phylogenetic reconstruction confirmed its placement within the T. brasiliensis species complex. Both approaches consistently supported T. chiarii sp. nov. as a species closely related to T. petrocchiae, but with sufficient phenotypic and genotypic divergence to warrant its recognition as a new taxonomic entity. Conclusions Since T. chiarii sp. nov. was also found in the peridomestic environment, its possible role in the eco-epidemiology of Chagas disease warrants further investigation.