Aspectos morfológicos, filogenéticos, morfométricos e biológicos de espécies do “Subcomplexo Rubrovaria” (Hemíptera: Reduviidae : Triatominae)

Abstract

In this thesis we studied three species of "subcomplex rubrovaria": T. carcavalloi, T. circummaculata and T. rubrovaria wild habits that have potential in transmission of Chagas disease. These species are often found in domiciles in the state of Rio Grande do Sul, Brazil. Comparisons were made between the three species by morphology using the technique of optical microscopy and scanning electron microscopy. We illustrate the morphostructural differences adults in scutellar region and only one species showed heart-shaped median depression, T. circummaculata. T. carcavalloi and T. rubrovaria presented in the form of W. It was also observed concentration of sensilla on the surfaces of the scutellum of these three species. In analyzes of the cephalic region, the stridulatory sulcus is "U" shaped in T. circummaculata and "V" shaped in T. carcavalloi and T. rubrovaria, the buccula T. carcavalloi and T. rubrovaria presented in the form of "U" and T. circummaculata "V" shaped. The rostrum of T. carcavalloi, T. circummaculata and T. rubrovaria presented in apex two lateral rifts 1+1. Were analyzed and shown significant differences in the length, width and diameter of the body and operculum of the eggs of T. rubrovaria, T. carcavalloi and T. circummaculata. In the morphological analysis of antennas T. carcavalloi it was verified the occurence in both sexes more than 14 trichobotrium, in the thrird and fourth antennal articles. T. carcavalloi presented on head 1+1 post-ocelares spots. In the legs, a pair of subapical denticles in femures of male and female was found. Spongy fossette were found only in the males, in the tíbias of the anterior and medium legs. The results of morphological T. carcavalloi showed that some structures are important for the specific characterization, such: antennas, spongy fossette and subapical denticles. Morphological studies placed T. carcavalloi in "complex infestans" and "subcomplex rubrovaria" as well as T. rubrovaria, while T. circummaculata was placed in the "complex circummaculata". The phylogeny of the group consists of 16 species of triatomines was reassessed with the inclusion of T. carcavalloi by Bayesian analysis of mtDNA sequences of subunits 12S and 16S ribosomal RNA, and cytochrome oxidase I gene (COI). The phenotypic relationship between T. carcavalloi related triatomines was also inferred from morphometry. Phylogenetic results indicate that T. carcavalloi is a sister species to T. rubrovaria, and both were relocated in close relationship with T. circummaculata. Morphometrics studies confirmed the proximity of T. carcavalloi, T. rubrovaria and T. circummaculata, placing the latter species the "complex infestans" and "subcomplex rubrovaria". Regarding biological parameter, the average incubation period of the eggs in T. carcavalloi was 22.7 days. The highest number of eggs/female/week was observed during the hottest months. The first meal took place at 3.13 days after hatching. The intermoulting period N1-N2 was on average 18.52 days, N2-N3 62.77, N3-N4 86.93, N4-N5 119.05 and N5–adult 193.43. The average of feedings during the nymphal development was 13.4. Resistance to fasting in all nymph and adult (males and females) stages indicated that nymphs of 3rd, 4th and 5th stages presented higher resistance than adults, and in this case males were less resistant than females. The highest mortality rate was registered in N3 (22.2%). The average adult survival was 25.6 weeks. The total life cycle was highly long with average of 503.4 days. This is the first report on the biology of T. carcavalloi fed mice. This study enable expand the bionomic knowledge of this species, besides contribute to better maintenance colony and thus understand the possible participation in the transmission of T. cruzi.