Molecular characterization of Rhodnius robustus specimens, potential vectors for Chagas disease in French Guiana, South America

Insects of the genus Rhodnius are broadly involved in Chagas disease transmission. In French Guiana, where the disease remains a public health problem, R. robustus and R. pictipes are vectors, but so far few genetic analyses of these local species have been reported. Here, we explored three mitochondrial genes (Cytb, Lsu-rRNA, and ND1) and one nuclear gene (D2) in 49 adult specimens morphologically characterized as R. robustus. We analyzed genetic polymorphisms and haplotype distributions, and we built phylogenetic trees using the available GenBank sequences from R. robustus and related species. The molecular taxonomy analysis confirmed that 35 insects, closely related to Brazilian species and separated by a few mutations, truly belong to R. robustus; two others were attributed to the R. prolixus complex and for 12 no sequence was obtained. The geographical haplotype distribution indicates a likely geographical structuring and evidenced true differentiation between the two main urban centers, Cayenne and Saint-Laurent-du-Maroni.