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Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958) (Hemiptera: Reduviidae: Triatominae) under laboratory conditions
Villacís, Anita G;Arcos-Terán, Laura;Grijalva, Mario J;
Memórias do Instituto Oswaldo Cruz , 2008, DOI: 10.1590/S0074-02762008000700011
Abstract: rhodnius ecuadoriensis is the second most important vector of chagas disease (cd) in ecuador. the objective of this study was to describe (and compare) the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of manabí (coastal region) and loja (andean region)]. egg-to-adult (n = 57) development took an average of 189.9 ± 20 (manabí) and 181.3 ± 6.4 days (loja). mortality rates were high among lojan nymphs. pre-feeding time (from contact with host to feeding initiation) ranged from 4 min 42 s [nymph i (ni)] to 8 min 30 s (male); feeding time ranged from 14 min 45 s (ni)-28 min 25 s (male) (manabí) and from 15 min 25 s (ni)-28 min 57 s (nymph v) (loja). the amount of blood ingested increased significantly with instar and was larger for manabí specimens (p < 0.001). defecation while feeding was observed in manabí specimens from stage nymph iii and in lojan bugs from stage nymph iv. there was a gradual, age-related increase in the frequency of this behaviour in both populations. our results suggest that r. ecuadoriensis has the bionomic traits of an efficient vector of trypanosoma cruzi. together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic r. ecuadoriensis populations in the coastal and andean regions may have a significant impact for cd control in ecuador and northern peru.
Aspectos morfológicos de ovos de triatominae: II - Características macroscópicas e exocoriais de dez espécies do gênero Rhodnius Stal, 1859 (Hemiptera - Reduviidae)
Barata,José Maria Soares;
Revista de Saúde Pública , 1981, DOI: 10.1590/S0034-89101981000500006
Abstract: morphological studies of exochorial patterns of rhodnius (hemiptera-reduviidae) genus were made. ten species were studied by scanning and common microscopy, and data were described mainly for systematic purposes. the species included are rhodnius domesticus neiva & pinto, 1923; r. ecuadoriensis lent & leon, 1958; r. nasutus stal, 1959; r. neglectus lent, 1954; r. neivai lent, 1953; r. pallescens barber, 1932; r. paraensis sherlock, guitton & miles, 1977; r. pictipes stal, 1872; r. prolixus stal, 1859; and r. robustus larrousse, 1927. general aspects of eggs and shells such as shape, color patterns, and size measurements are also presented. data about changes of coloration occurred during egg maturation were recorded and related to the embryonic development. the characteristics described were utilized to work out identification keys for these triatominae eggs, both by optical and scanning electron microscopy.
Observations on the Domestic Ecology of Rhodnius ecuadoriensis (Triatominae)
Abad-Franch, F;Aguilar V, HM;Paucar C, A;Lorosa, ES;Noireau, F;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000200010
Abstract: rhodnius ecuadoriensis infests peridomiciles and colonises houses in rural southern ecuador. six out of 84 dwellings (7%) surveyed in a rural village were infested (78 bugs/infested domicile; 279 bugs were collected in a single dwelling). precipitin tests revealed r. ecuadoriensis fed on birds (65%), rodents (31%), marsupials (8%), and humans (15%) - mixed bloodmeals detected in 37.5% of individual samples. trypanosoma cruzi from opossums and rodents may thus be introduced into the domestic cycle. wasp parasitoidism was detected in 6.5% of 995 r. ecuadoriensis eggs (only in peridomestic habitats). control strategies should integrate insecticide spraying (indoors and peridomestic), better management of poultry, and housing improvements. a possible inefficacy of malathion is reported.
Observations on the Domestic Ecology of Rhodnius ecuadoriensis (Triatominae)  [cached]
Abad-Franch F,Aguilar V HM,Paucar C A,Lorosa ES
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: Rhodnius ecuadoriensis infests peridomiciles and colonises houses in rural southern Ecuador. Six out of 84 dwellings (7%) surveyed in a rural village were infested (78 bugs/infested domicile; 279 bugs were collected in a single dwelling). Precipitin tests revealed R. ecuadoriensis fed on birds (65%), rodents (31%), marsupials (8%), and humans (15%) - mixed bloodmeals detected in 37.5% of individual samples. Trypanosoma cruzi from opossums and rodents may thus be introduced into the domestic cycle. Wasp parasitoidism was detected in 6.5% of 995 R. ecuadoriensis eggs (only in peridomestic habitats). Control strategies should integrate insecticide spraying (indoors and peridomestic), better management of poultry, and housing improvements. A possible inefficacy of Malathion is reported.
The Triatomines of Northern Peru, with Emphasis on the Ecology and Infection by Trypanosomes of Rhodnius ecuadoriensis (Triatominae)
Cuba Cuba, César A;Abad-Franch, Fernando;Roldán Rodríguez, Judith;Vargas Vásquez, Franklin;Pollack Velásquez, Luis;Miles, Michael A;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000200005
Abstract: information on the distribution and synanthropic behaviour of triatomines is essential for chagas disease vector control. this work summarises such information from northern peru, and presents new data on rhodnius ecuadoriensis - an important local vector infesting 10-35% of dwellings in some zones. three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the mara?ón river system. r. ecuadoriensis and triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern peru. confirmation of this hypothesis would result in a local eradication strategy being recommended. presence of trypanosome natural infection was assessed in 257 r. ecuadoriensis; trypanosoma rangeli was detected in 4% of bugs. six further triatomine species are potential disease vectors in the region (t. carrioni, p. chinai, p. rufotuberculatus, p. geniculatus, r. pictipes, and r. robustus), whilst eratyrus mucronatus, e. cuspidatus, cavernicola pilosa, hermanlentia matsunoi, and belminus peruvianus have little or no epidemiological significance. a strong community-based entomological surveillance system and collaboration with ecuadorian public health authorities and researchers are recommended.
The Triatomines of Northern Peru, with Emphasis on the Ecology and Infection by Trypanosomes of Rhodnius ecuadoriensis (Triatominae)  [cached]
Cuba Cuba César A,Abad-Franch Fernando,Roldán Rodríguez Judith,Vargas Vásquez Franklin
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: Information on the distribution and synanthropic behaviour of triatomines is essential for Chagas disease vector control. This work summarises such information from northern Peru, and presents new data on Rhodnius ecuadoriensis - an important local vector infesting 10-35% of dwellings in some zones. Three species are strongly synanthropic and may be suitable targets for chemical control of domestic/peridomestic bug populations. Panstrongylus herreri, the main domestic vector in the area, is probably present in sylvatic ecotopes in the Mara ón river system. R. ecuadoriensis and Triatoma dimidiata seem exclusively domestic; biogeographical and ecological data suggest they might have spread in association with humans in northern Peru. Confirmation of this hypothesis would result in a local eradication strategy being recommended. Presence of trypanosome natural infection was assessed in 257 R. ecuadoriensis; Trypanosoma rangeli was detected in 4% of bugs. Six further triatomine species are potential disease vectors in the region (T. carrioni, P. chinai, P. rufotuberculatus, P. geniculatus, R. pictipes, and R. robustus), whilst Eratyrus mucronatus, E. cuspidatus, Cavernicola pilosa, Hermanlentia matsunoi, and Belminus peruvianus have little or no epidemiological significance. A strong community-based entomological surveillance system and collaboration with Ecuadorian public health authorities and researchers are recommended.
Adult and nymphs of Microtriatoma trinidadensis (Lent, 1951) (Hemiptera: Reduviidae) caught from peridomestic environment in Bolivia
De la Riva, J;Matias, A;Torrez, M;Martínez, E;Dujardin, JP;
Memórias do Instituto Oswaldo Cruz , 2001, DOI: 10.1590/S0074-02762001000700001
Abstract: this is the first report of adult and nymphs (20 nymphs of all stages and 4 adults) of microtriatoma trinidadensis (lent 1951) (hemiptera: reduviidae: triatominae) collected in peridomestic environment, in the department of la paz, bolivia. these specimens were associated to rhodnius stali lent, jurberg & galv?o 1993. the exceptional finding of m. trinidadensis in peridomestic environment, illustrates the general tendency of triatominae to adapt to human dwellings and dependences.
Adult and nymphs of Microtriatoma trinidadensis (Lent, 1951) (Hemiptera: Reduviidae) caught from peridomestic environment in Bolivia
De la Riva J,Matias A,Torrez M,Martínez E
Memórias do Instituto Oswaldo Cruz , 2001,
Abstract: This is the first report of adult and nymphs (20 nymphs of all stages and 4 adults) of Microtriatoma trinidadensis (Lent 1951) (Hemiptera: Reduviidae: Triatominae) collected in peridomestic environment, in the department of La Paz, Bolivia. These specimens were associated to Rhodnius stali Lent, Jurberg & Galv o 1993. The exceptional finding of M. trinidadensis in peridomestic environment, illustrates the general tendency of triatominae to adapt to human dwellings and dependences.
ULTRASTRUCTURAL OBSERVATIONS ON Trypanosoma (Herpetosoma) rangeli IN THE SALIVARY GLANDS OF Rhodnius ecuadoriensis (Hemiptera, Reduvidae)
KITAJIMA,ELLIOT W; CUBA CUBA,CESAR A; BRENER,ZIGMAN;
Parasitología al día , 1998, DOI: 10.4067/S0716-07201998000300002
Abstract: an electron microscopy study was carried out on the salivary glands of the triatomine bug rhodnius ecuadoriensis experimentally infected with a peruvian strain of trypanosoma (herpetosoma) rangeli. epimastigotes forms of t. rangeli were found in large numbers in the haemolymph surrounding the salivary gland. some of them were closely associated with the basal lamina of the gland epithelium, apparently in a process of cell invasion, in which the flagellum breaking through the basal lamina. within the cytoplasm of the gland epithelial cells, there were rounded forms of t. rangeli, consisting of tightly coiled sphaeromastigotes. the gland lumen was filled with large numbers of mostly epimastigotes forms of the flagellate; only few paramastigotes and trypomastigotes forms could be unequivocally identified. the presence of paramastigotes in the life cycle of t. rangeli has yet to be fully assessed
ULTRASTRUCTURAL OBSERVATIONS ON Trypanosoma (Herpetosoma) rangeli IN THE SALIVARY GLANDS OF Rhodnius ecuadoriensis (Hemiptera, Reduvidae)
ELLIOT W KITAJIMA,CESAR A CUBA CUBA,ZIGMAN BRENER
Parasitología al día , 1998,
Abstract: An electron microscopy study was carried out on the salivary glands of the triatomine bug Rhodnius ecuadoriensis experimentally infected with a Peruvian strain of Trypanosoma (Herpetosoma) rangeli. Epimastigotes forms of T. rangeli were found in large numbers in the haemolymph surrounding the salivary gland. Some of them were closely associated with the basal lamina of the gland epithelium, apparently in a process of cell invasion, in which the flagellum breaking through the basal lamina. Within the cytoplasm of the gland epithelial cells, there were rounded forms of T. rangeli, consisting of tightly coiled sphaeromastigotes. The gland lumen was filled with large numbers of mostly epimastigotes forms of the flagellate; only few paramastigotes and trypomastigotes forms could be unequivocally identified. The presence of paramastigotes in the life cycle of T. rangeli has yet to be fully assessed Fué realizado un estudio ultraestructural de las glándulas salivares del triatomino Rhodnius ecuadoriensis experimentalmente infectado por el tripanosomatídeo, Trypanosoma (Herpetosoma) rangeli, con la finalidad de documentar los aspectos básicos de la infección glandular por este flagelado. Gran número de formas epimastigotes fueron encontradas en la hemolinfa que ba a la parte externa de las glándulas en el hemoceloma. Algunos flagelados parecían íntimamente asociados a la membrana basal del epitelio glandular y varios de ellos parecían estar iniciando el proceso de su invasión, rompiendo la lámina basal con el flagelo. En el interior de las células glandulares observamos que, T. rangeli se presentaba en la forma de esferomastigotes, células redondeadas rodeadas externamente por un flagelo, que envolvía apretadamente el parásito. En la luz glandular también observamos gran número de epimastigotes mezclados con los productos de la secreción glandular; el material presentó apenas pocas formas paramastigotes y trypomastigotes identificadas de manera inequívoca. El significado de los paramastigotes en el ciclo evolutivo del T. rangeli aguarda futuros estudios
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