Jader de Oliveira

Multiple mitochondrial genes of some sylvatic Brazilian Triatoma: Non-monophyly of the T. brasiliensis subcomplex and the need for a generic revision in the Triatomini

Multiple fragments of mitochondrial DNA genes (cytochrome b, cytochrome oxidase I, and 16S rDNA) were used to evaluate the phylogenetic relationships among Triatoma melanocephala, Triatoma tibiamaculata, Triatoma vitticeps, and other members of Triatoma brasiliensis subcomplex under a Bayesian framework and maximum parsimony criterion. With the addition of new sequences of T. tibiamaculata and T. vitticeps, Triatoma juazeirensis, Triatoma melanica and the newly sequenced T. melanocephala, the three first sylvatic species, T. melanocephala, T. tibiamaculata and T. vitticeps, were strongly recovered into a clade separate from the other with the remaining Triatoma species from South America, such as the members of T. brasiliensis subcomplex. Panstrongylus megistus was recovered as a sister to T. tibiamaculata, whereas T. vitticeps was a sister to T. melanocephala. This study revealed the non-monophyly of the T. brasiliensis subcomplex, and the polyphyly of Triatoma was reinforced by the placement of these three sylvatic species with Dipetalogaster, Meccus, Mepraia, and Panstrongylus. The results herein shown highlight the need of generic revision in Triatomini.

Description of Rhodnius marabaensis sp n. (Hemiptera, Reduviidade, Triatominae) from Para State, Brazil

Abstract Rhodnius marabaensis sp. n. was collected on 12 May 2014 in the Murumurú Environmental Reserve in the city of Marabá, Pará State, Brazil. This study was based on previous consultation of morphological descriptions of 19 Rhodnius species and compared to the identification key for the genus Rhodnius. The examination included specimens from 18 Rhodnius species held in the Brazilian National and International Triatomine Taxonomy Reference Laboratory in the Oswaldo Cruz Institute in Rio de Janeiro, Brazil. The morphological characteristics of the head, thorax, abdomen, genitalia, and eggs have been determined. Rhodnius prolixus and Rhodnius robustus were examined in more detail because the BLAST analysis of a cyt-b sequence shows they are closely related to the new species, which also occurs in the northern region of Brazil. The most notable morphological features that distinguish Rhodnius marabaensis sp. n. are the keel-shaped apex of the head, the length of the second segment of the antennae, the shapes of the prosternum, mesosternum and metasternum, the set of spots on the abdomen, the male genitalia, the posterior and ventral surfaces of the external female genitalia, and the morphological characteristics of the eggs. Rhodnius jacundaensis Serra, Serra & Von Atzingen (1980) nomen nudum specimens deposited at the Maraba Cultural Center Foundation - MCCF were examined and considered as a synonym of Rhodnius marabaensis sp. n.

Study of the external female genitalia of 14 Rhodnius species (Hemiptera, Reduviidae, Triatominae) using scanning electron microscopy

BackgroundAmong the vectors of Chagas disease (Hemiptera: Reduviidae:Triatominae), there are eighteen Rhodnius species described and some are difficult to identify. The aim of this article is to contribute to the specific identification of fourteen Rhodnius spp. through morphological characters of the external female genitalia.MethodsFemale abdomens were cut transversely. The specimens were then prepared for examination by using scanning electron microscopy.ResultsThe careful examination of the dorsal, posterior and ventral sides revealed characteristics that allowed the identification of each of the fourteen species.ConclusionThe use of external female genitalia as characteristics are proposed as a tool for specifically identifying Rhodnius species, and an identification key for these species is presented.

Nucleolar persistence during spermatogenesis of the genus Rhodnius (Hemiptera, Triatominae)

The Triatominae subfamily is comprised of 18 genera and six tribes. The tribe Rhodniini is comprised of two genera (Rhodnius and Psammolestes). Nucleolar persistence is defined by the presence of the nucleolus or nucleolar corpuscles during the meiotic metaphase. To date, this phenomenon has been described for 13 species of triatomine that are included in the genera Triatoma, Rhodnius, and Panstrongylus. Thus, because the phenomenon of nucleolar persistence has been described in only two species of the genus Rhodnius, we have analyzed the nucleolar behavior during spermatogenesis of eight species of the genus Rhodnius (R. colombiensis, R. montenegrensis, R. nasutus, R. neglectus, R. neivai, R. pictipes, R. prolixus, and R. robustus), with a focus on nucleolar persistence. By means of cytogenetic analysis with silver ions, nucleolar behavior during spermatogenesis is described in the eight species of Rhodnius analyzed. In all of them nucleolar behavior was similar and the phenomenon of nucleolar persistence was often observed. Therefore, we confirm nucleolar persistence as a peculiarity of the genus Rhodnius. However, it is emphasized that new cytogenetic analysis should be performed in the Triatominae subfamily, more specifically among the 15 genera that do not exhibit the nucleolar behavior described, in order to assess whether this phenomenon is truly a synapomorphy of these hematophagous insects.

A new species of Rhodnius from Brazil (Hemiptera, Reduviidae, Triatominae)

Abstract 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.

First report of Rhodnius stali (Hemiptera, Reduviidae, Triatominae) in the State of Acre and in the Brazilian Amazon.

INTRODUCTION This paper reports, for the first time, the presence of Rhodnius stali in the state of Acre and in the Brazilian Amazon. METHODS Specimens of R. stali were collected by the Federal University of Acre in Rio Branco. RESULTS The number of Triatominae species in the State of Acre increased from five to six. This was also the first report of R. stali in the Brazilian Amazon. CONCLUSIONS The occurrence of R. stali is worrisome, since this species has been found naturally infected by Trypanosoma cruzi and there has been evidence of its domiciliation capabilities.

Chromosomal characteristics and distribution of constitutive heterochromatin in the Matogrossensis and Rubrovaria subcomplexes

Since 1966 the triatomines were grouped in complexes and specific subcomplexes. Although the complex and subcomplexes not have taxonomic importance, should be monophyletic groups and cytogenetic tools have proved to be of great importance to characterize these species groupings. Based on this, this paper aims to describe the chromosomal characteristics and heterochromatic pattern of Matogrossensis and Rubrovaria subcomplexes, in order to contribute to the taxonomic and evolutionary relationships of these vectors. In this study, at least three males from each species (Triatoma baratai, Triatoma costalimai, Triatoma guazu, Triatoma jurbergi, Triatoma matogrossensis, Triatoma vandae, Triatoma williami, Triatoma carcavalloi, Triatoma circummaculata, Triatoma klugi, Triatoma pintodiasi and Triatoma rubrovaria) were analyzed by means analyzed by means of cytogenetic techniques of C-banding. All species showed the same cytogenetic characteristics: 22 chromosomes, low variation in the size of autosomes, sex chromosome Y larger than X, initial prophase composed of only one heterochromatic chromocenter formed by the sex chromosomes X and Y (except for T. pintodiasi that presented the sex chromosomes individualized during all stages of prophase) and presence of constitutive heterochromatin restricted to sex chromosome Y. These characteristics, although common to Matogrossensis and Rubrovaria subcomplexes allow to distinguish these species of species grouped in most of South America subcomplexes, as Brasiliensis, Maculata, Sordida and Insfestans. Thus, the cytogenetic analysis was of extreme importance to differentiate both subcomplexes of the other subcomplexes of South America. However, probably due to evolutionary proximity existing between these subcomplexes was not possible to observar species differences that make up the Matogrossensis subcomplex of the Rubrovaria subcomplex. Therefore, we emphasize that new comparative analyzes, as experimental hybrid crosses and molecular cytogenetic analysis are necessary to clarify the evolutionary relationship between these important subcomplexes of vectors.

Cystic spermatogenesis in three species of the prolixus complex (Hemiptera: Triatominae)

Abstract The reproductive biology of triatomines and, more specifically, the general aspects of spermatogenesis and spermiogenesis are well known. However, reported structural analyses of the testicles are restricted to the genus Triatoma. Thus, this paper describes the spermatogenesis of three species of the genus Rhodnius (R. neglectus, R. prolixus and R. robustus), by means of structural analysis. The general analysis of semi-thin sections of testicular follicles of R. prolixus, R. robustus and R. neglectus revealed that spermatogenesis is cystic in these species. Furthermore, the structural analysis of the spermatogenesis of R. prolixus (Colombia and Costa Rica), R. robustus and R. neglectus showed stages of spermatogenesis. In this paper, the analysis of spermatogenesis of three Rhodnius species shed light on this cystic spermatogenesis phenomenon; no intraespecific differences were observed among R. prolixus from different countries. Thus, although new structural analyses in other genera of the subfamily Triatominae should be performed, this paper describes cystic spermatogenesis in three species of the genus Rhodnius. These results contribute to the knowledge of the class Insecta and allow for a more detailed study of the reproductive biology of these important vectors of Chagas disease.

Taxonomic status of Panstrongylus herreri Wygodzinsky, 1948 and the number of Chagas disease vectors

Univ Estadual Paulista, Lab Parasitol, Dept Ciencias Biol, Fac Ciencias Farmaceut, Araraquara, SP, Brazil

First report of Triatoma sordida Stål, 1859 (Hemiptera, Reduviidae, Triatominae) in the State of Acre and Brazilian Western Amazon

INTRODUCTION The occurrence of Triatoma sordida in the Brazilian Western Amazon is reported for the first time. METHODS Triatoma sordida specimens were collected from a Gallus gallus nest in a peridomiciliary area of Senador Guiomard municipality in the state of Acre. RESULTS The number of triatomine species in Acre increased from six to seven with this first report of T. sordida in the Brazilian Western Amazon. CONCLUSIONS The occurrence of T. sordida in Acre is of concern since it is among the most captured triatomines in peridomiciliary environments in Brazil, and carries a high potential for vector transmission.