Triatoma sordida (Stål, 1859) (Hemiptera, Triatominae): a Chagas Disease vector or a complex of vectors?

Abstract

Triatoma sordida is one of the main species with vector competence for the transmission of Chagas' disease in Brazil, which also occurs in Argentina, Bolivia, Paraguay and Uruguay. Several studies indicate a polymorphism in T. sordida, which led to the suggestion of the cryptic speciation phenomena in this species and, above all, the recent characterization of three possible different taxa, namely T. sordida sensu stricto, T. sordida Argentina and T. sordida La Paz. Taking into account that the realization of experimental crosses can help in different aspects, such as the understanding of taxonomy, systematics and isolation mechanisms that limit gene flow, as well as the possibility of evaluating the role of natural hybridization in the generation of new genetic variants (which may lead to adaptive evolution and or the foundation of new evolutionary lineages), the present project aims to analyze the possible barriers of reproductive isolation (pre or post zygotic) present between T. sordida sensu stricto, T. sordida Argentina and T. sordida La Paz, by means of experimental crosses and analysis of the resulting hybrids until the second generation (F2), with emphasis on the analysis of the evolutionary dynamics of experimental crosses (interspecific copulation, oviposition, hatching and hybrids development), as well as in the analysis of the reproductive viability of the hybrids (spermatogenesis and morphology of the male and female gonads). These results will allow elucidating evolutionary and taxonomic questions about T. sordida and the process of cryptic speciation.