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RESUMOUma nova espécie críptica de Triatoma é descrita dentro do subcomplexo T. rubrovaria. As diferenças entre T. pintodiasi sp. nov. e T. circummaculata incluem, entre outras, o padrão cromático e diferenças morfológicas nas estruturas fálicas, como nos parâmeros, suporte do falosoma, processo do endosoma e vesica. Análises bioquímicas realizadas na hemolinfa e a comparação morfométrica da cabeça também registraram diferenças entre as duas espécies e outras do subcomplexo T. rubrovaria. Palavras

Triatoma nitida is a wild species occurring in Mexico and Central America. In order to establish the length of its life cycle andtransmission potential, the following parameters were observed: the incubation period, the interval between hatching, or moulting, and the first feeding; the number of blood meals and the time of development. The time-lapse before the bite, the length of feeding and the interval between the end of the blood meal and defecation, as well as the site of defecation were also analyzed. Average length of the egg incubation period was 18.2 days. Time interval between the food source offering and the bite was less than 4 min in 60% of the analyzed cases, except in the fifth instar, where only 38% of the insects began feeding in less than 5 min. The blood-sucking period was long and rising until the fifth instar, decreasing in adults, and ranging from 1 min to 2 and a half hours. Only 26% of the blood meals were followed by defecations within 20 min. The average length of the life cycle was 897.5 days.

Biology of

Descritores Rhodnius

R. brethesi is a sylvatic species from the Amazon region; it has been incriminated as responsible for the transmission of Chagas disease in collectors of piacaba in this region. The aim of present study was to investigate the efficiency of these insects as potential vectors of Trypanosoma cruzi. Aspects related with feeding and defecation patterns, life time, and mortality had been observed in each instar of R. brethesi. We use 5th instar nymphs to get adults virgins, after the moulting 3 groups with 6 females and 2 males each were created to obtain eggs. After hatching, 1st instar nymphs had been weighed and kept in bottles until the next moult. Insects were fed once a week in mice. Results showed that the average period of incubation was 17 days, the number of blood meal was increasing from the 1st to the 5th instar nymph with 7 (average) to become adult, a significative numbers of the defecations occurring immediately after the bloodmeals. The total percentual of mortality was 16%. This results suggests that this species presents a good exploitation of blood meals and a brief nymphal development in laboratory conditions reflecting its behavior in sylvatic environments.

Resumo O objetivo do presente trabalho foi observar o desenvolvimento de R. neglectus em diferentes condições de temperatura e umidade. Três grupos foram formados:33/40 (33+/-1 o C e 40% +/-5% UR), 33/70 (33+/-1 o C e 70% +/-5% UR), e 28/70 (28+/-1 o C e 70% +/-5% UR). Todos os grupos foram observados diariamente para avaliação do período de incubação dos ovos, período de desenvolvimento dos estádios ninfais, percentual de mortalidade por estádio, número de repastos realizados, e período de desenvolvimento da eclosão a muda imaginal. O desenvolvimento embrionário apresentou diferenças significativas em todos os tratamentos, o grupo 33/40 apresentou o menor período de incubação. O menor número de repastos foi observado no grupo 33/40 exceto para o primeiro estádio (grupo 28/70). O período de desenvolvimento ninfal foi significativamente reduzido no grupo 33/40; entretanto, o percentual de mortalidade deste grupo foi alto, e os insetos não conseguiram realizar a muda imaginal. Palavras-chaves: Rhodnius neglectus. Triatominae. Doença de Chagas. Temperatura. Umidade. AbstractThe objective of the present paper was to study the development of R. neglectus in the laboratory under different conditions of temperature and humidity. Three groups were prepared: 33/40 (33+/-1 o C and 40% +/-5% UR), 33/70 (33+/-1 o C and 70% +/-5% UR), and 28/70 (28+/-1 o C and 70% +/-5% UR). All these groups were observed daily to evaluate the eggs' incubation period, the development period of each instar nymph, the mortality rate of each stage, the frequency of feeding and the hatching -adult ecdysis period. The embryonic development showed significant differences between the treatment given, the group 33/40 presented the lowest incubation period. The lowest bloodmeals number was observed in the group 33/40 except for the first instar (group 28/70). The period of nymphal development was significantly reduced in the group 33/40, however, the mortality was high and the specimens did not reach the adult phase.

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