Species-specific differences in the egg exochorium of the sympatric taxa Triatoma costalimai and Triatoma jatai (Hemiptera: Reduviidae: Triatominae).

Triatoma costalimai and Triatoma jatai are related species, which occur in sympatry in Paranã, Tocantins, Brazil, in rocky outcrops and in peridomicile and intradomicile environments. This study compared morphologic and morphometric aspects of the eggs of these species using optical microscopy (OM) and scanning electron microscopy (SEM). Operculum cells (OP) and egg body (EB) were drawn and photographed, their surfaces were measured, and spots were quantified. Statistical analyses were performed using ANOVA and t-tests. OM showed an egg exochorium with spots in T. costalimai and a predominance of short lines in T. jatai. We found significant differences in egg length and width, which were larger in T. costalimai. SEM analysis showed that the operculum of both species had cells with straight and/or rounded rims, with a smooth aspect, random spots, and predominantly pentagonal shape. In the EB, hexagonal cells were predominant, with indices exceeding 60% in both species. Triatoma costalimai cells were flat, with a discrete definition of the rims, whereas T. jatai cells were smooth with well-defined rims. Statistical tests showed significant differences for EB, where T. costalimai cells were larger and have more spots than T. jatai. The eggs can thus be differentiated, thereby contributing to integrative taxonomy.

External female genitalia of Triatoma jatai, Triatoma costalimai and Triatoma williami (Hemiptera: Reduviidae: Triatominae).

BACKGROUND: Taxonomic identification of triatomines is generally performed based on aspects of their external morphology. However, the use of a multidisciplinary approach, considering morphological aspects of the external genitalia, morphometry, genetics, and phylogeography has been suggested, especially for similar and/or cryptic species. The rupestral species Triatoma jatai Gonçalves et al., 2013, Triatoma costalimai Verano & Galvão, 1959 and Triatoma williami Galvão et al., 1965, which are morphologically similar, have been found naturally infected with Trypanosoma cruzi (Chagas, 1909) in wild, peridomestic, and intradomestic environments, representing a risk of new outbreaks of Chagas disease. This study presents morphological description complementation of these species, with an emphasis on the structures of the female external genitalia, using scanning electron microscopy. METHODS: The females of T. jatai and T. costalimai (n = 10 of each) were captured in the Brazilian municipalities of Paranã and Aurora do Tocantins and were identified with the use of a dichotomous key for the Matogrossensis subcomplex. Females of T. williami (n = 5), were obtained from a laboratory colony. The females were cut transversely at the sixth abdominal segment and examined under scanning electron microscopy (SEM) at the Oswaldo Cruz/Fiocruz Institute Electronic Microscopy Platform. RESULTS: It was possible to differentiate the three species based on the characteristics of urotergites VII, VIII and IX and urosternite VII, as well as the genital plaques, gonocoxites, and gonapophyses. To our knowledge, morphological differences in the spines present on gonapophysis 8 in triatomines are described here for the first time. CONCLUSIONS: The results show that external genitalia of females are useful structures to differentiate T. costalimai, T. jatai and T. williami. SEM analysis contributes to and corroborates, together with other tools morphological and molecular, the distinction of the three species.

Interactions between malnutrition, soil-transmitted helminthiasis and poverty among children living in periurban communities in Maranhao State, Northeastern Brazil.

Poverty, malnutrition and neglected tropical diseases such as soil-transmitted helminthiases (STHs) interact in a multi-causal feedback network. This study aimed to assess the relationships between STHs, income and nutritional status of children in impoverished communities in the city of Caxias, Maranhao State, Northeastern Brazil. A cross-sectional survey (n=259 children) was carried out with the collection of fecal samples and assessment of sociodemographic, anthropometric, dietary and sanitation data. Hookworm infection and ascariasis presented prevalence rates of 14.3% and 9.3%, respectively. The logistic regression analysis showed that hookworm infection was more frequent in males (odds ratio [OR]=3.43; 95% confidence interval [CI]=1.45-8.08), children aged 11-15 years old (OR=3.72; 95% CI=1.19-11.62), children living in poor families (OR=2.44; 95% CI=1.04-5.68) and those living in rented houses (OR=5.74; 95%CI=1.91-17.25). Concerning ascariasis, living in the Caldeiroes community (OR=0.01; 95%CI=0-0.17) and belonging to the 11-15 years age group (OR=0.21; 95%CI=0.04-1.02) were protection factors. Poor children have a significantly lower frequency of consumption of meat, milk, vegetables, tubers and fruits than not poor children. The frequent consumption of meat, milk and tubers was associated with significant higher values in the parameter height-for-age, whereas the consumption of meat and milk positively influenced the weight-for-age. The frequencies of stunting, underweight and wasting were 8.1%, 4.9% and 2.9%, respectively. The multivariate model demonstrated that stunting was significantly associated with economic poverty (OR=2.82; 95%CI=1.03-7.70) and low weight was associated with male sex (OR=6.43; 95% CI=1.35-30.68). In conclusion, the study describes the interactions between the dimensions of development represented by income, STHs and nutritional status revealing the importance of raising income levels to improve the living conditions of families in impoverished communities in Northeastern Brazil.

Morphological Aspects of Antennal Sensilla of the Rhodnius brethesi Matta, 1919 (Hemiptera: Reduviidae) from the Negro River, Amazon Region of Brazil.

Studies conducted in river Ererê located in the left margin of Negro River, municipality of Barcelos, state of Amazonas, have confirmed that Rhodnius brethesi has as its natural habitat the palm tree Leopoldinia piassaba. By scanning electron microscopy, sensillum type was studied on the antennae of R. brethesi. The specimens used come from the field and laboratory colony. No differences were observed between R. brethesi and other Triatominae studied. In the R. brethesi antennas, differences were observed only between the antennal segments and in the dorsal and ventral portions. Trichobothria sensilla show a difference with a lamellar base, suggesting that this conformation of the base of the sensilla is a synapomorphic feature of the genus. Another important observation is that, considering that R. brethesi is a specialist, infesting only one type of palm tree, trichoidea sensilla may be involved with plant-derived odorants. The knowledge of such functions could benefit the understanding of the likely biological role of these structures in chemical communication and also provide basic information for future studies of niche recognition, since this species of triatomine is only found in the L. piassaba palm.

Triatomine dispersion rates and their association with socioeconomic and environmental conditions in Northeastern Brazil, from 2009 to 2013.

Triatomines are vectors of Trypanosoma cruzi , the etiological agent of Chagas disease, which affects between 6 and 12 million people in Latin America, with an incidence rate of 12 thousand cases per year. In the Ceara State, the predominance of the caatinga biome, coupled with a large rural area with precarious human habitations, provides several s shelters for these insects. In this study, we determined the spatiotemporal distribution of triatomine dispersion rates in the Cariri region, Southern Ceara and ascertained the possible association between these rates with socioeconomic and environmental factors. Dispersion rates (number of positive localities/number of searched localities × 100) were analyzed regarding 13 municipalities from the Ceara State, from 2009 to 2013. Socioeconomic and environmental variables collected from national research institutes were associated with the dispersion rates and their local empirical Bayesian estimates. All the municipalities recorded dispersion rates over 10% in all years, and 11 municipalities had average rates over 40% for the period of study. Significant differences were observed among the municipality means. The highest rates were observed in Antonina do Norte and Potengi. According to the correlation analysis, the proportion between the occupied population and the total population showed a significant negative correlation, as well as the percentage of the population who lives under adequate sanitary conditions. Both, the percentage of revenues from external sources and the percentage of urban households in reforested blocks had a significant positive correlation. Our results show that socioeconomic and environmental variables can be factors that contribute to both, the maintenance and the reduction of the elevated dispersion rates observed in the study area. Similar researches that encompass more municipalities from that region may reinforce Chagas disease surveillance and control in the Northeast of Brazil.

Characterization of the Buccula, Rostrum, Stridulatory Sulcus, Scutellum, and External Female Genitalia of Triatoma carcavalloi (Jurberg, Rocha & Lent, 1998), Triatoma circummaculata (Stål, 1859), and Triatoma rubrovaria (Blanchard, 1843) (Hemiptera, Reduviidae, Triatominae).

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.

Spermatological Morphology of Triatoma Species (Hemiptera: Reduviidae: Triatominae).

Spermatozoa are among the most diverse cell types, and their morphologies often provide data that can be used to reliably evaluate phylogenetic relationships. They can also help to clarify the nature of 'specific complexes', which are common among triatomines. In the present study, we evaluated the copulation behavior of Triatoma rubrovaria Blanchard 1843 (Hemiptera: Reduviidae: Triatominae) and the structural morphology of sperm from T. carcavalloi Jurberg Rocha & Lent, 1998, T. infestans Klug, 1834, T. pintodiasi Jurberg Cunha & Rocha, 2013, and T. rubrovaria. Copulatory behavior was described from the moment males and females genitalia joined until they separated. Insemination was confirmed by the presence of a spermatophore in the female's bursa copulatrix. To measure their sperm, males were dissected and their seminal vesicles were removed, squashed on glass slides, and then spread, fixed, and observed under a photomicroscope. The images obtained were analyzed to measure the sperm. Seminal vesicles were also prepared for transmission electron microscopy. We performed K-means clustering separately for each species to group their sperm based on morphology. The differences in spermatozoa length among species of Triatominae, sperm types, and the interaction between species and sperm type were assessed with a two-way analysis of variance (ANOVA). The copulation time in T. rubrovaria was 3 to 5 min, which was sufficiently long for spermatophore transfer. All taxa showed polymorphic (short and long) sperm, with significant differences in the lengths of sperm among taxa. Using electron microscopy, the sperm cells of the four taxa examined were found to have similar ultrastructural morphology, confirming the hypothesized synapomorphies of sperm within the suborder Heteroptera (Hemiptera).

New sex-determination system in the genus Panstrongylus (Hemiptera: Reduviidae) revealed by chromosomal analysis of Panstrongylus lutzi.

BACKGROUND: Panstrongylus lutzi (Neiva & Pinto, 1923) is a triatomine species native to Caatinga habitats in north-eastern Brazil. It is considered an important vector of Chagas disease in this region, presenting high rates of natural infection with Trypanosoma cruzi Chagas, 1909, and readily invading houses by flight. This study describes a previously unknown chromosomal sex system in the genus Panstrongylus based on P. lutzi. METHODS: Fifth-instar and male adults of P. lutzi originating from municipality of Várzea Alegre, Ceará (Brazil) were analysed. Chromosomal analyses of male meiotic process were done by Giemsa staining. RESULTS: Chromosomal analyses of male meiosis reveal a diploid chromosome number of 24 chromosomes (20 autosomes plus X1X2X3Y). During meiotic prophase I, the sex chromosomes remained close together, forming four heteropycnotic chromocenters in zygotene, and a single chromocenter in pachytene and diplotene. Still at the diplotene stage, each one of the ten autosomal bivalents showed an evident chiasma. In metaphase I, the four sex chromosomes appeared clearly separated. The three X chromosomes were the smallest of the complement and isopycnotic with respect to the Y chromosome. Two bivalents appear larger, whereas the other eight showed no significant difference in size. CONCLUSION: Karyotype analysis of P. lutzi revealed a new sex system in the genus Panstrongylus. This result is of utmost importance to karyosystematics of P. lutzi, and demonstrates the need for further studies of this type in the subfamily Triatominae.

Surveillance of Chagas disease vectors in municipalities of the state of Ceará, Brazil

The present study aimed to analyse the dwelling infestation rates and the distribution and natural Trypanosoma cruzi infection rates, among triatomines captured in the 13 municipalities of the state of Ceará. The records relating to the capture of intradomicile and peridomicile triatomines during the Chagas disease control program of 1998-2008 were available. Among the triatomines captured and in all of the municipalities studied, Triatoma brasiliensis presented the highest incidence in intradomicile and Triatoma pseudomaculata in peridomicile and some were positive for infection by T. cruzi. We emphasise that it is important to have sustainable epidemiological surveillance in the region, since when the control measures decreased, the incidence of T. pseudomaculata in intradomicile grew.

Surveillance of Chagas disease vectors in municipalities of the state of Ceará, Brazil.

The present study aimed to analyse the dwelling infestation rates and the distribution and natural Trypanosoma cruzi infection rates, among triatomines captured in the 13 municipalities of the state of Ceará. The records relating to the capture of intradomicile and peridomicile triatomines during the Chagas disease control program of 1998-2008 were available. Among the triatomines captured and in all of the municipalities studied, Triatoma brasiliensis presented the highest incidence in intradomicile and Triatoma pseudomaculata in peridomicile and some were positive for infection by T. cruzi. We emphasise that it is important to have sustainable epidemiological surveillance in the region, since when the control measures decreased, the incidence of T. pseudomaculata in intradomicile grew.

Vigilância entomológica dos vetores da doença de Chagas no município de Farias Brito, Estado do Ceará, Brasil / Entomological surveillance of Chagas' disease vectors in Farias Brito city, State of Ceará, Brazil

Este artigo tem por finalidade descrever a situação entomológica do Programa de Controle da Doença de Chagas Humana no município de Farias Brito, Estado do Ceará, no período 2001-2002. Dados secundários referentes à captura triatomínica de sete áreas do Programa Saúde da Família: Barreiro do Jorge, Carás dos Alcântaras, Cariutaba, Carnaúba dos Ribeiros, Monte Pio, Nova Betânia e Quincuncá são apresentados. Os resultados obtidos referentes à taxa de infestação, a dispersão e a distribuição geográfica das espécies possibilitaram avaliar a capacidade de colonização. Paralelamente, foi feita uma estimativa da prevalência dos índices de infecção natural dos triatomíneos pelo Trypanossoma cruzi. Das cinco espécies vetoras autóctones, Triatoma brasiliensis, Triatoma psedomaculata, Panstrongylus megistus, Panstrongylus lutzi e Rhodnius nasutus, as duas primeiras são nativas, ubiquistas, predominantemente peridomiciliares e de difícil controle. Um trabalho de vigilância epidemiológica de caráter contínuo se faz necessário, uma vez que a desativação regional da Fundação Nacional de Saúde impõe a absorção das atividades pelo município.

Fine structure of the male accessory glands of Triatoma rubrofasciata (De Geer, 1773) (Hemiptera, Triatominae).

Male of Triatoma rubrofasciata has four elongated sac-like reproductive mesodermic accessory glands, lined by an inner single layer of secretory cells, with basal plasma membrane infolds and short apical microvilli, and externally enveloped by a thin visceral muscle layer. The secretory cells have a well-developed rough endoplasmic reticulum, Golgi complex, mitochondria, and secretory granules. In one day old adult the gland cells are poorly developed, presenting small, electron-transparent secretory granules scattered among the rough endoplasmatic reticulum, whereas in three days old adult these cells have the cisternae of the rough endoplasmatic reticulum varing size degree, filled with granular electrondense content. In five days old males the secretory granules increase in diameter, being released to the gland lumen. Therefore, there is an increase of the secretory activity according to male maturation.

Development, survival and reproduction of Podisus nigrispinus (Dallas, 1851) (Heteroptera: Pentatomidae) with salt and amino acids solutions supplementary diet

O presente estudo mostra o efeito da suplementação alimentar com soluções de aminoácidos e salina (NaCl) no desenvolvimento, sobrevivência e reprodução de Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae). Ambas soluções causaram efeito deletério na sobrevivência ninfal, peso dos adultos, longevidade das fêmeas e nos números de posturas, de ovos/fêmea, de ovos/postura e de ninfas, bem como na viabilidade dos ovos de P. nigrispinus quando comparado com estes insetos que além de presa receberam água. Estes resultados são discutidos em comparação com o efeito positivo que a suplementação alimentar com plantas tem sido relatada para esses predadores e sugerem que o uso de plantas é melhor que a substituição por solução de aminoácidos em sistemas de criação em laboratório desses predadores.

Fontes alimentares de Triatoma pseudomaculata no Estado do Ceará, Brasil / Feeding patterns of Triatoma pseudomaculata in the state of Ceará, Brazil

OBJETIVO: Triatoma pseudomaculata, espécie peridomiciliar, é encontrada apresentando baixa taxa de infecção por Trypanosoma cruzi. Com o objetivo de identificar os possíveis reservatórios de T. cruzi, investigou-se a ocorrência desse triatomíneo no domicílio, bem como suas fontes alimentares. MÉTODOS: De janeiro de 2001 a julho de 2002 foram capturados 921 espécimes de T. pseudomaculata em 13 municípios do sul do Estado do Ceará. O conteúdo intestinal dos triatomíneos foi retirado, espalhado em disco de papel de filtro e analisado por precipitina para os seguintes anti-soros: ave, roedor, cão, gambá, lagarto, boi/cabra, gato, porco, barata e humano. A investigação da presença de T. cruzi foi feita observando-se parte do conteúdo intestinal dos insetos a fresco, entre lâmina e lamínula, e pela sua semeadura em meio de cultura. RESULTADOS: Do total examinado, 184 (90,6 por cento) foram positivos para os anti-soros testados: ave (62,5 por cento)> roedor (33,7 por cento)> cão (20,1 por cento)> gambá (9,8 por cento)> lagarto (5 por cento)> boi-cabra (5 por cento)> gato (2,7 por cento)> porco (2,2 por cento)> barata (2,2 por cento)> humano (1,6 por cento). As alimentações variaram de zero (não reagiram) a quatro da seguinte forma: não reagiram (9,4 por cento), uma (57,1 por cento), duas (26 por cento), três (7 por cento) ou quatro (0,5 por cento). Das fontes alimentares identificadas apenas três espécimes (1,6 por cento) foram positivos para T. cruzi. CONCLUSÕES: A baixa incidência de sangue humano mostra que T. pseudomaculata está bem adaptado ao peridomicílio. Porém, a vigilância epidemiológica na região sul do Estado do Ceará se faz necessária tendo em vista a proximidade da espécie ao domicílio.

[Feeding patterns of Triatoma pseudomaculata in the state of Ceara, Brazil]. / Fontes alimentares de Triatoma pseudomaculata no Estado do Ceará, Brasil.

OBJECTIVE: T. pseudomaculata, a peridomicilar species, has low rates of T. cruzi infection. The occurrence of this triatomine in the domicile and its feeding patterns was investigated to identify potential T. cruzi reservoirs. METHODS: Nine-hundred and twenty-one specimens of T. pseudomaculata were captured from January 2001 to July 2002 in 13 southern municipalities of the state of Ceara, Brazil. The intestinal contents of the triatomines was removed, spread in a filter paper and tested for the following antisera: bird, cat, cockroach, dog, human, lizard, opossum, ox/goat, pig, and rodent. The presence of T. cruzi was investigated by wet mount microscopic exam and culture (NNN+LIT) of intestinal contents. RESULTS: Of the total studied, 184 (90.6%) were positive for the tested antisera: bird (62.5%)> rodent (33.7%)> dog (20.1%)> opossum (9.8%)> lizard and ox/goat (5%)> cat (2.7%)> pig and cockroach (2.2%)> human (1.6%). Blood meals ranged from none (non-reactive) to four as follows: non-reactive (9.4%), one (57.1%), two (26%), three (7%), and four (0.5%). Only three specimens (1.6%) had T. cruzi infection. CONCLUSIONS: The low incidence of human blood meal shows that T. pseudomaculata is well-adjusted to the peridomicile. However, the epidemiological vigilance in this region is key due to this species' proximity to domiciles.

[Occurrence of Panstrongylus lutzi, in peridomiciliary areas, State of Ceará, Brazil]. / Ocorrência de Panstrongylus lutzi no peridomicílio, Estado do Ceará, Brasil.

From January 2001 to October 2002 captures were made in domicile and peridomiciliary areas of 13 cities of region of Cariri, south of the State of Ceará. As results, the occurrence of P. lutzi in this area was noticed, for the first time, in three cities: the presence of one adult in chicken house in Altaneira, one adult flying, in Salitre and 18 nymphs in Varzea Alegre(13 in bricks pile and five in roofing tile pile). In Varzea Alegre city it was observed the colonization in the peridomicile.

Ocorrência de Panstrongylus lutzi no peridomicílio, Estado do Ceará, Brasil / Occurrence of Panstrongylus lutzi, in peridomiciliary areas, State of Ceará, Brazil

Durante o período de janeiro de 2001 a outubro de 2002, foram feitas capturas no domicílio e peridomicílio de 13 municípios da região do Cariri, sul do Estado do Ceará. Como resultados, foi registrada pela primeira vez nessa região a ocorrência de P. lutzi em três municípios: presença de um adulto em galinheiro em Altaneira, um adulto voando, em Salitre; e de 18 ninfas, em Várzea Alegre (13 foram coletadas em amontoado de tijolos e cinco em amontoado de telhas). Em Várzea Alegre, foi observada a colonização no peridomicílio.

[Influence of anthropic habits in the dispersion of Triatoma pseudomaculata Corrêa & Espínola, 1964 through Mimosa tenuiflora (Willdenow) (Mimosaceae) in the State of Ceará, Brazil]. / Influência de hábitos antrópicos na dispersão de Triatoma pseudomaculata Corrêa & Espínola, 1964, através de Mimosa tenuiflora (Willdenow) (Mimosaceae) no Estado do Ceará, Brasil.

Triatoma pseudomaculata was captured in the phloem of the black acacia bush (Mimosa tenuiflora) in seven municipalities in the State of Ceará, Brazil. This bush is widespread in the caatinga (scrub forest) and is used extensively by the rural population for kindling. Peridomiciliary presence of triatomines in the Cariri region may be associated with the use of infested M. tenuiflora wood by the population, thus facilitating the triatomines' mobilization and dispersion.

Influência de hábitos antrópicos na dispersão de Triatoma pseudomaculata Corrêa & Espínola, 1964, através de Mimosa tenuiflora (Willdenow) (Mimosaceae) no Estado do Ceará, Brasil / Influence of anthropic habits in the dispersion of Triatoma pseudomaculata Corrêa & Espínola, 1964 through Mimosa tenuiflora (Willdenow) (Mimosaceae) in the State of Ceará, Brazil

Triatoma pseudomaculata foram capturados em entrecascas de Mimosa tenuiflora (jurema-preta) em ecótopo silvestre de sete municípios do Estado do Ceará. Esta planta apresenta alta taxa de cobertura geográfica nas áreas de caatingas, sendo freqüentemente utilizada pela população rural. A presença de triatomíneos no peridomicílio, na região do Cariri, pode estar associada ao uso pela população da madeira de M. tenuiflora, quando trazida do ambiente silvestre, repleta de triatomíneos, facilitando conseqüentemente sua mobilização e dispersão.