RESUMO
In Brazil, Triatoma rubrovaria (Blanchard, 1843) is the most important species in epidemiological terms in the State of Rio Grande do Sul, due to its wide geographical distribution in this state, followed by T. carcavalloi (Jurberg, Rocha & Lent, 1998) and T. circummaculata (Stål, 1859). Structural analysis of the ventral region of the head (rostrum and buccula), thorax (stridulatorium sulcus and scutellum), and external female genitalia of adults of T. rubrovaria, T. carcavalloi, and T. circummaculata is described here. Scutellum, head, rostrum, and part of the thorax (prosternum) containing the stridulatory sulcus, in both male and female, and the sixth abdominal segment of the female, containing the external genitalia, were processed for scanning electron microscopy studies as routine. Morphological differences in the analyzed structures for all the three Triatoma species studied were detected under scanning electron microscopy. This study confirms the grouping of the T. rubrovaria, T. carcavalloi, and T. circummaculata in 'T. rubrovaria subcomplex' by their morphological similarities.
