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BACKGROUND:Chagas disease is caused by the parasite Trypanosoma cruzi and is transmitted through triatomines (Hemiptera: Reduviidae). In the last year, many studies of triatomine gut microbiota have outlined its potential role in modulating vector competence. However, little is known about the microbiota present in the salivary glands of triatomines. Bacterial composition of salivary glands in selected triatomine species was investigated, as well as environmental influences on the acquisition of bacterial communities.METHODOLOGY/PRINCIPAL FINDINGS:The diversity of the bacterial communities of 30 pairs of salivary glands of triatomines was studied by sequencing of the V1- V3 variable region of the 16S rRNA using the MiSeq platform (Illumina), and bacteria isolated from skin of three vertebrate hosts were identified based on 16S rRNA gene sequence analysis (targeting the V3-V5 region). In a comparative analysis of microbiota in the salivary glands of triatomine species, operational taxonomic units belonging to Arsenophonous appeared as dominant in Triatoma spp (74% of the total 16S coverage), while these units belonging to unclassified Enterobacteriaceae were dominant in the Rhodnius spp (57% of the total 16S coverage). Some intraspecific changes in the composition of the triatomine microbiota were observed, suggesting that some bacteria may have been acquired from the environment.CONCLUSIONS AND SIGNIFICANCE:Our study revealed the presence of a low-diversity microbiota associated to the salivary glands of the evaluated triatomines. The predominant bacteria genera are associated with triatomine genera and the bacteria can be acquired in the environment in which the insects reside. Further studies are necessary to determine the influence of bacterial communities on vector competence.

INTRODUCTION: Studying the feeding preferences of triatomines is an important entomological surveillance tool, since continuous surveillance of the disease is necessary. METHODS: The precipitin reaction was used to describe the feeding preferences of triatomines along with their natural infection by flagellates similar to Tyrpanosoma cruzi. Six hundred eighty-seven insects were examined, including Triatoma brasiliensis, Triatoma pseudomaculata, and Panstrongylus lutzi. RESULTS: Sixty-nine (10%) of 687 triatomines examined tested positive for flagellates similar to T. cruzi, and 8 (1.2%) of these fed on human blood. CONCLUSIONS: This study found potential transmitters of Chagas disease both inside and outside the domiciliar environment.

Chagas disease is most frequently transmitted to humans through contact with feces of insects from the Triatominae subfamily. In Brazil, there are 65 species of triatomines distributed throughout the country's 27 states. Among the species in the state of Rio Grande do Sul, Triatoma rubrovaria, Triatoma oliveirai, Triatoma pintodiasi, Triatoma klugi, Triatoma carcavalloi, and Triatoma circummaculata (with the addition Triatoma limai, which is endemic to Argentina) form the T. rubrovaria subcomplex. The last species described and grouped into this subcomplex was T. pintodiasi Thus, this study characterized the genetic distance between T. pintodiasi and of the other members of the T. rubrovaria subcomplex to evaluate the specific status of T. pintodiasi The genetic distance observed between T. pintodiasi and the other species of the T. rubrovaria subcomplex was large, a finding which highlights the specific status of the species considered to be cryptic of T. circummaculata.

Triatoma infestans is a mandatory haematophagous vector of Chagas disease in Brazil. Despite a large number of studies on the anti-haemostatic molecules present in its saliva, the role of its salivary components on parasite transmission is poorly understood. Here, we show that the bioactive lipid molecule, lysophosphatidylcholine (LPC), is present in the salivary gland of T. infestans. We characterized the lipid profiles of each unit of the T. infestans salivary gland. We noticed that LPC is present in the three units of the salivary gland and that the insect feeding state does not influence its proportion. T. infestans saliva and LPC can enhance T. cruzi transmission to mice by dramatically altering the profile of inflammatory cells at the site of inoculation on mouse skin, facilitating the transmission of T. cruzi to the vertebrate host. Consequently, the mortality curves of either saliva- or LPC-injected mice display significant higher mortality rates than the control. Altogether, these results implicate LPC as one of key salivary molecule involved in Chagas disease transmission.

Triatoma pintodiasi has been described and recently grouped in the Rubrovaria subcomplex. T. pintodiasi was initially compared to T. carcavalloi by staining and subsequently identified as T. circummaculata. However, after thorough examination, it was observed to be a cryptic species of T. circummaculata, and was described based on morphological features, morphometric data, and biochemical patterns of hemolymph. Thus, this paper aims to describe the karyotype of, and spermatogenesis in, T. pintodiasi, in order to elucidate the reproductive biology and taxonomy of the species. Sex chromosomes of T. pintodiasi formed a heteropyknotic chromocenter, and compaction of chromatin was observed during prophase. However, in contrast to observations in T. carcavalloi and T. circummaculata, in T. pintodiasi it was observed individualization of the sex chromosomes. The diploid chromosome set of the species 2n = 22 (20A + XY) is described through analysis of metaphases I and II. Initial cytogenetic characteristics of T. pintodiasi are described and the observed differences in the chromocenter are suggested as a possible cytotaxonomic tool. To gain a better understanding of the specific status of this cryptic species, however, we emphasize the need for further cytogenetic, molecular, biological, and biogeographical analysis, in addition to experimental hybrid crosses with other species of the Rubrovaria subcomplex.

The first report of the occurrence of Panstrongylus geniculatus (Latreille) 1811 was reported in the state of Pernambuco. Therefore its distribution was amplified, and now, such as P. megistus, is the most widely distributed species in Brazil. P. geniculatus was found by health workers in intradomiciliary environments in Vitoria de Santo Antao, testing positive for flagellates observed by direct examination of intestinal contents, and Giemsa staining.

The first report of the occurrence of Panstrongylus geniculatus (Latreille) 1811 was reported in the state of Pernambuco. Therefore its distribution was amplified, and now, such as P. megistus, is the most widely distributed species in Brazil. P. geniculatus was found by health workers in intradomiciliary environments in Vitoria de Santo Antao, testing positive for flagellates observed by direct examination of intestinal contents, and Giemsa staining.

Using classic morphometric techniques to examine the head and thorax of Triatoma specimens, researchers identified a possible taxonomic problem involving T. arthurneivai (Lent & Martins) and T. wygodzinskyi (Lent). A recent geometric morphometric study indicated that the insects captured outside the Serra do Cipó region, State of Minas Gerais, Brazil, were T. wygodzinskyi. The misidentification of T. arthurneivai as T. wygodzinskyi could result in several problems associated with entoepidemiological lifting, the biological characterization of the species, and phylogenetic reconstruction. For the first time, we describe the use of cytogenetic analysis as a tool for differentiation between T. arthurneivai and T. wygodzinskyi. The results indicated that both species had the same number of chromosomes 2n = 22 (20A + XY). However, analyses of spermatocytes during early prophase indicated that it was possible to differentiate T. arthurneivai and T. wygodzinskyi, because only T. arthurneivai exhibited heteropycnotic blocks distributed in the chromatin. Therefore, we highlight the analysis of spermatocytes as a taxonomic tool for the characterization of T. arthurneivai and T. wygodzinskyi, and suggest that the technique can be used for entoepidemiological lifting in vector control programs. Thus, the results presented here, in conjunction with morphometric analyses, are of utmost taxonomic and epidemiological importance for the identification of T. arthurneivai and T. wygodzinskyi specimens.

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Spermatogenesis is composed of three distinct phases: spermatocytogenesis, which is the proliferation phase; meiosis, which is the division phase; and spermiogenesis, which is the differentiation phase (Johnson et al. 1997).In insects the spermatogenesis is cystic (Dumser 1980). In cystic spermatogenesis, the meiotic divisions are synchronous within a given cyst (Smith 1916). This phenomenon has been confirmed in the subfamily Triatominae (Silistino-Souza et al. 2011; Alevi et al. 2015).

Objectives: To underscore the importance of geographic distribution and behavior of vectors ofChagas disease in the state of Pernambuco. Methods: The material analyzed included 100% of theinsects infected with Trypanosoma spp., and 40% of negative insects, examined at the EndemicDisease Laboratory for taxonomic confirmation, searching for the parasite in feces of the insects,with Quality Control to confirm the diagnosis. Results: A total of 3,323 triatomines. Naturalinfection by trypanosomes was detected in 21.3% of the specimens. Triatoma brasiliensis wasthe most frequent intradomiciliary species (24.3%), outside the home Triatoma pseudomaculata(14.9%) and Panstrongylus megistus had a natural infection rate proportionally superior to the others(40.8%). Conclusion: The current knowledge of the geographical distribution of Chagas diseasevectors is important as a platform to integrate actions between health services, contributing to theentomological surveillance and control of the insects.

Resumen En Peru, se han reportado 18 especies de triatominos y como vector principal de Trypanosoma cruzi a Triatoma infestans . En el nororiente del Peru habitan varias especies de triatominos encontradas infec­tados en forma natural con trypanosomatideos compatibles a T. cruzi y/o T. rangeli. Su actual area de dispersion en ecotopos peridomiciliares, domiciliares y posiblemente silvestres es desconocida y pobre­mente estudiada, por lo que el objetivo del presente trabajo es establecer diferencias en las observaciones de campo y parametros biologicos de los triatominos, importantes para la planificacion de estrategias de programas de control vectorial. La busqueda y colecta de especimenes se realizo mediante la tecnica activa de captura manual hombre/hora en distintas localidades en el nororiente del Peru. Fue registrada la presencia de huevos, exoco­rion, ecdisis, ninfas y adultos machos y hembras en ambientes clasicamente descritos como habitat de triatominos domiciliares (dormitorios, tarimas, grietas en paredes). Gallineros y cuyeros localizados en el peridomicilio tambien fueron infestados. Se presenta el analisis de la informacion de campo y los parametros biologicos de Triatoma carrioni, Panstrongylus lignarius, P. chinai, Hermanlentia matsunoi y P. rufotuberculatus capturados en las locali­dades de Asiayaco y Socchabamba (Ayabaca), Chiple (Cutervo) y Lamas (San Martin), Guitarras y Jibito (Sullana), Pias (Pataz) y Suyo (Ayabaca), con sus respectivas semejanzas y diferencias. A pesar de que en las especies estudiadas no se ha encontrado infeccion natural por Trypanosoma , la frecuente migracion de la poblacion condiciona su potencial como vectores de la Enfermedad de Chagas; por lo que se recomienda vigilancia entomo-epidemiologica para estas especies que coexisten simpatri­camente en esta region del Peru. Palabras clave : Hermanlentia matsunoi Triatoma carrioni, Panstrongylus lignarius, P. chinai, P. rufotuber­culatus, Triatominae, vectores, enfermedad de Chagas. Abstract In Peru, has been reported 18 species of triatomines and as the main vector of Trypanosoma cruzi to Triatoma infestans ; in the northeast of Peru several species of triatomine were found infected naturally with compatible trypanosomatideos to T. cruzi and/or T. rangeli . The current dispersion area in domiciliary, peridomiciliaries, and possibly wild ecotopes is unknown and poorly studied. The objective of the present is to report field observations and some biological parameters for planning strategies of vector control pro­grams. The search and collection of specimens was carried out using active manual capture man/hour in different towns of northeast of Peru. It was registered the presence of eggs, exocorion, ecdysis, nymphs and adult males and females in classically described environments as habitats of triatomines domiciliary (bedrooms, decking, cracks in walls). Chicken coops and cuyeros located in the peridomiciliary were also infested. It´s presented information with similarities and differences from field observations and biolo­gical parameters of Triatoma carrioni, Panstron­gylus lignarius, P. chinai, Hermanlentia matsunoi and P. rufotuberculatus captured in the towns of Asiayaco (Ayabaca), Chiple (Cutervo) and Lamas (San Martin), guitars (Sullana), Pias (Pataz) and (Ayabaca), respectively. In spite hat natural infec­tion by Trypanosoma not be found in the studied species, the frequent migration of the population could determines its potential as vectors of Cha­gas disease; so it is recommended entomo-epide­miological surveillance for these species that co-exist sympatrically in this region of Peru. Key words : Hermanlentia matsunoi Triatoma ca­rrioni, Panstrongylus lignarius, P. chinai, P. rufotu­berculatus, Triatominae, vectors, Chagas disease.

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.

INTRODUCTION:The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection.METHODS:The fieldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at five selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads.RESULTS:In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher efficiency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests.CONCLUSIONS:Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruziin the Pantanal region.

The members of the subfamily Triatominae (Heteroptera, Reduviidae) are vectors of Trypanosoma cruzi (Chagas), the causative agent of Chagas disease or American trypanosomiasis. As important vectors, triatomine bugs have attracted ongoing attention, and thus, various aspects of their systematics, biology, ecology, biogeography, and evolution have been studied for decades. In the present chapter, the authors summarize the current knowledge on the systematics, phylogeny, evolution, and biology of these vectors and discuss the implications for human health.

Triatoma rubrofasciata (De Geer) is the first species of triatomine described, and little is known on its vector biology. Studies are restricted to starvation resistance, interspecific morphometric variability, morphometry of testis follicles, coloration of the testicular peritoneal sheath, ultrastructure of the male accessory glands, phylogeny and cytogenetics. Thus, this study aims to address the karyosystematics of T. rubrofasciata and the possible events related to karyotype evolution of this species. Four adult males were analyzed cytogenetically. The analysis of meiotic metaphases of T. rubrofasciata allowed to confirm the karyotype of species, out more, 2n = 25 (22A + X1X2Y). This number is very important for taxonomic and evolutionary inferences on the species, because of the 88 triatomine species with described karyotype, only T. rubrofasciata exhibits 25 chromosomes. Based on the hypothesis of the karyotype 2n = 22 (20A + XY) as ancestral for triatomines, we propose three evolutionary hypotheses for the emergence of the karyotype of T rubrofasciata, all supported by agmatoploidy events (fission). Basically the hypotheses are 1) fission for a pair of autosomes, resulting in 22 autosomes and later fission of sex chromosome X; 2) fission of pair of autosomes and the sex chromosome X concomitantly; 3) fission of sex chromosome X and subsequently fission of pair of autosomes. Thus, this study highlights for the first time the importance of the number of chromosomes of T. rubrofasciata as characteristic diagnosis in Triatominae subfamily and describes three evolutionary hypotheses that possibly led the emergence of karyotype of this insect of global importance.