Aspects of the male reproductive system in Triatoma species (Hemiptera, Reduviidae, Triatominae)

Nos Triatominae, Triatoma rubrofasciata é uma espécie cosmopolita, encontrada em alguns municípios da costa brasileira e Triatoma brasiliensis é o principal vetor da doença de Chagas no Nordeste brasileiro, distribuindo-se no sertão dos Estados do Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Bahia e Minas Gerais. Recentes estudos, em relação a esta última, demonstraram tratar-se do complexo brasiliensis , constituído por: Triatoma brasiliensis brasiliensis, T. brasiliensis macromelasoma, T. melanica e T. juazeirensis. No presente estudo foram relacionadas as características morfológicas e citoquímicas do sistema reprodutor masculino envolvidas a aspectos taxonômicos e reprodutivos em espécies de Triatoma. Os folículos testiculares em T. rubrofasciata apresentaram quatro categorias, um longo, dois médios, dois curtos e dois muitos curtos, enquanto que as demais espécies mantiveram a classificação descrita para Triatoma, dois longos, dois médios e três curtos. Em relação às glándulas acessórias de T. rubrofasciata, T. brasiliensis e T. melanica, grânulos secretores são vistos no epitélio glandular, antes do quinto dia de vida adulta, nos machos em jejum alimentar. A produção de carboidratos e proteínas, possivelmente para a formação do espermatóforo, inicia-se em T. melanica antes de T. brasiliensis, porém nesta última a produção é mais intensa a partir do quinto dia. Sendo o espermatóforo essencial para o transporte e manutenção do esperma nos insetos, estudos sobre as funções secretoras das glândulas acessórias masculinas podem contribuir para o desenvolvimento de novas estratégias de controle dos vetores da doença de Chagas.In Triatominae, Triatoma rubrofasciata is a cosmopolitan species, found in some cities of the Brazilian coast and Triatoma brasiliensis is main vector of Chagas disease in the Northeastern Brazil, distributed in the States of Maranhão, Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Bahia and Minas Gerais. Recent studies showed the existance of the brasiliensis complex constituted by: T. brasiliensis brasiliensis, T. brasiliensis macromelasoma, T. juazeirensis and T. melanica. In present study were related the morphological and citochemical caracteristics of the male reproductive system involved with taxonomics and reproductives aspects in Triatoma species. The follicles testis in T. rubrofasciata presented four categories, a long one, two medium, two short and two very short follicles, whereas the other species maintened the normal classification for Triatoma, two long, two medium and three short follicles. In relation to the accessory glands of T. rubrofasciata, T. brasiliensis and T. melanica, secretory granules we seen in the glandular epithelium before the fifth day of adult life, in males starved. Carbohidrates and proteins production, possibly for spermatophore formation, begin in T. melanica before than in T. brasiliensis. However in this last species this production is more intense from the fifth day. Being the spermatophore essential for the transport and maintenance of sperm in insects, studies on the secretory functions of the male accessory glands may contribute to the development of new control strategies of vectors of Chagas disease.Fundação de Amparo a Pesquisa do Estado de Minas Gerai

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