Phylogeny and molecular taxonomy of the Rhodniini derived from mitochondrial and nuclear DNA sequences

Eleven species of Rhodnius and one of Psammolestes were compared by DNA seq uence analysis of fragments of the mitochondrial large subunit ribosomal RN A (mtlsurRNA), the mitochondrial cytochrome b (mtCytb), and the D2 variable region of the 28S nuclear RNA (D2), totaling 1,429 base pairs. The inferre d phylogeny, using Triatoma infestans as an outgroup, revealed two main cla des within the Rhodniini-one, including the prolixus group of species (Rhod nius prolixus, Rhodnius robustus, Rhodnius neglectus, and Rhodnius nasutus) together with Rhodnius domesticus and Rhodnius neivai, and the other compr ising two groups formed by Rhodnius pictipes plus Rhodnius brethesi, and Rh odnius ecuadoriensis plus Rhodnius pallescens. Psammolestes tertius appeare d most closely related to the prolixus group. The analysis strongly support s the validity of R. robustus as a species distinct from others of the prol ixus group, but suggests higher genetic structuring of R. robustus populati ons compared to the other species. Although R. robustus has been found natu rally infected by Trypanosoma cruzi, the fact that it is apparently entirel y sylvatic and unable to establish in homes suggests that it is of no great importance as a Chagas disease vector in humans.