No abstract

We present here a multisource approach that takes advantage of several disciplines to address a taxonomic issue. A triatomine related to Rhodnius robustus Larrousse, 1927 was recently found in the state of Rondônia, Brazil. The name Rhodnius montenegrensis n. sp. is suggested because it was found in the municipality of Monte Negro. The main differences between these two species can be detected in the female and male genitalia, but there are also noticeable differences in their eggs. Molecular analysis using PCR-RFLP technique and Bayesian inferences based on a fragment of the Cytochrome b (Cyt b) gene corroborated the morphological findings. We used this integrative approach to address the taxonomic decision for a new Rhodnius species and its relationship with others of this genus. Results obtained herein stress that morphology must be used as the major approach for obtaining phenotypic information, and molecular data should be taken as a complementary tool.

A colony was formed from eggs of a Rhodnius sp. female collected in Taquarussu, Mato Grosso do Sul, Brazil, and its specimens were used to describe R. taquarussuensis sp. n. This species is similar to R. neglectus, but distinct characters were observed on the head, thorax, abdomen, female external genitalia and male genitalia. Chromosomal differences between the two species were also established.

Triatoma melanocephala is a rare species of Hemiptera that belongs to the Brasiliensis subcomplex. This subcomplex is composed of cryptic species, and the basic number of chromosomes for triatomines of this subcomplex is 2n = 22; however, T. melanocephala showed a karyotype of 2n = 24 (20A + X(1)X(2)X(3)Y). Thus, this study allowed us to describe the karyotype of the species and, more specifically, to propose the exclusion of T. melanocephala, as well as T. vitticeps and T. tibiamaculata, which also has fragmentation of the X chromosome, from the Brasiliensis subcomplex.