O presente trabalho tem a finalidade de estudar o comportamento de triatomíneos no interior de ecótopos artificiais. Para tanto, construiu-se galinheiro experimental com paredes internas formadas por blocos de barro desmontáveis, abrigando aves como fonte alimentar. O galinheiro foi subdividido em 4 áreas, duas destas separadas por telas e tijolos furados, sendo a menor o local de soltura dos triatomíneos e a maior o galinheiro propriamente dito. Dessa maneira buscou-se a coleta de informações a respeito do deslocamento, sobrevida e locais de abrigo de ninfas do 4º estádio de Triatoma brasiliensis, na certeza de que os mesmos iriam se acomodar nas proximidades da fonte alimentar. As paredes do galinheiro foram desmontadas e pesquisadas mensalmente durante 6 meses e as ninfas encontradas, marcadas com diferentes cores de acordo com o mês da leitura e a posição das mesmas nas áreas. Os resultados alcançados mostraram que 88,5% das ninfas estavam engorgitadas e foram encontradas próximas ao local de repouso (poleiro) da fonte alimentar. Após a primeira alimentação, não abandonavam as proximidades da fonte. Os resultados alcançados apresentam, não apenas interesse epidemiológico, como também interesse na área de controle dos vetores da doença de Chagas, tendo em vista as possíveis implicações quanto aos procedimentos na aplicação do inseticida.

In order to study the behavior of triatomine bugs under artificial ecotopic conditions, an experimental, double-walled poultry coop was built. Its inside walls were made of sun-dried clay blocks which could be broken apart for better access to the insects hiding in their crevices. The coop was subdivided into two main areas of different sizes using wire netting and a wall made of perforated bricks. The chickens, the only food source available for the triatomines, were kept in the larger, rectangular area, further subdivided diagonally. The triatomines were released in the smaller area and were allowed to migrate to the larger one though the holes in the bricks. Information about migration, survival, and hiding places of fourth-stage nymphs of Triatoma brasiliensis was thus gathered. At 30-day intervals, over a period of six months, the inner walls of the house were taken apart and inspected. The nymphs were marked with different colors according to the month and place of capture. It was found that 88.5% of the nymphs were captured near the roost and found engorged. After having taken their first blood meal, they would remain in the vicinity of their food source. The results obtained are considered epidemiologically relevant, and particularly so as pertaining to the control of the vectors of Chagas’ disease.

O presente trabalho tem a finalidade de estudar o comportamento de triatomíneos no interior de ecótopos artificiais. Para tanto, construiu-se galinheiro experimental com paredes internas formadas por blocos de barro desmontáveis, abrigando aves como fonte alimentar. O galinheiro foi subdividido em 4 áreas, duas destas separadas por telas e tijolos furados, sendo a menor o local de soltura dos triatomíneos e a maior o galinheiro propriamente dito. Dessa maneira buscou-se a coleta de informações a respeito do deslocamento, sobrevida e locais de abrigo de ninfas do 4º estádio de Triatoma brasiliensis, na certeza de que os mesmos iriam se acomodar nas proximidades da fonte alimentar. As paredes do galinheiro foram desmontadas e pesquisadas mensalmente durante 6 meses e as ninfas encontradas, marcadas com diferentes cores de acordo com o mês da leitura e a posição das mesmas nas áreas. Os resultados alcançados mostraram que 88,5% das ninfas estavam engorgitadas e foram encontradas próximas ao local de repouso (poleiro) da fonte alimentar. Após a primeira alimentação, não abandonavam as proximidades da fonte. Os resultados alcançados apresentam, não apenas interesse epidemiológico, como também interesse na área de controle dos vetores da doença de Chagas, tendo em vista as possíveis implicações quanto aos procedimentos na aplicação do inseticida.

In order to study the behavior of triatomine bugs under artificial ecotopic conditions, an experimental, double-walled poultry coop was built. Its inside walls were made of sun-dried clay blocks which could be broken apart for better access to the insects hiding in their crevices. The coop was subdivided into two main areas of different sizes using wire netting and a wall made of perforated bricks. The chickens, the only food source available for the triatomines, were kept in the larger, rectangular area, further subdivided diagonally. The triatomines were released in the smaller area and were allowed to migrate to the larger one though the holes in the bricks. Information about migration, survival, and hiding places of fourth-stage nymphs of Triatoma brasiliensis was thus gathered. At 30-day intervals, over a period of six months, the inner walls of the house were taken apart and inspected. The nymphs were marked with different colors according to the month and place of capture. It was found that 88.5% of the nymphs were captured near the roost and found engorged. After having taken their first blood meal, they would remain in the vicinity of their food source. The results obtained are considered epidemiologically relevant, and particularly so as pertaining to the control of the vectors of Chagas’ disease.

In paralel with several other epidemiologic and entomologic data of 19 Municipalities of Espírito Santo State, Brazil, the feeding pattern of 222 Triatoma vitticeps is studied through precipitin tests. Very high levels of natural infection with Trypanosoma cruzi are observed in adult insects, in contrast with the abscence or minimum degrees of infection among nymphs and human individuals. The precipitin tests showed the contact of the insects with multiple blood sources, chiefly human and birds, followed by rodents and marsupials. The data suggest that T. vitticeps in spite of being highly antropophilic, become infected by T. cruzi in sylvatic ambient and occasionally invade houses. The species doesn't seem to be - at least until now - a good vector in the domestic cycle of Chagas' disease. Several factors seem to be involved in this conclusion, mainly the low density of the insect in the houses, its hardness to coloniza them, its slowness concerning to suction and defecation and possibly its low susceptibility to different T. cruzi strains.