A local distribution pattern of Triatoma sordida and Rhodnius neglectus is described after an intensive investigation on natural and artificial ecotopes. The work was carried in a region at north of the State of São Paulo, Brazil. Measures of dispersion pattern were made by the Morisita’s indices showing contagious distributions to both bugs. The T. sordida population was clumped at houses and surrounding dwellings, while R. neglectus presented the same aspect but relater to palm trees. The first bug showed […]

Investigations on triatomids behaviour in the counties Guaira and Sertãozinho of São Paulo State, Brazil, are presented. Precipitin tests showed differents blood meals in Triatoma sordida, and mainly from avian source in Rhodnius neglectus. Nevertheless it was probably due to opportunities and not to any hematofagous preference on birds or mammals. Investigation at artificial ecotopes, represented by houses and outbuildings, showed common invasion of these dwellings by Triatoma sordida and, in a very scarce manner, by Rhodnius neglectus. This leads […]

An evident structural process allowing the distinction between the Rhodnius neglectus and R. prolixus eggs is described. The former presents a complete collar occupying the preopercular region whilst in the latter species this formation is lacking.

Third and fourth instars of Rhodnius neglectus and Triatoma infestans were fed on wild opossums (Didelphis) with natural infeccions by Trypanosoma cruzi and, examined at regular 3.5 days intervals. Best results were obtained with rectum examinations and the infeccion was more easily detected from the 15th to the 20th days. R. neglectus showed better performance than T. infestans and so its utilisation in the xenodiagnosis technique is suggested.

The results of observation of sylvatic triatominae population in a region of intensive agricultural and cattle breeding activity are reported. Important environmental changes had occurred in the area, including destruction of the primitive vegetation and intensive use of pesticides. Nevertheless, these modifications apparently did not affect the survival of Triatominae, since they were found in the remaining vegetation. Moreover, this destruction seems to have favored, to some extent, survival of Triatoma sordida by increasing the available ecotopes. This species, as […]

Spontaneous colonies of Triatoma sordida, Panstrongylus megistus, and Rhodnius neglectus developed in experimental fowlhouses were observed for the conditions for their development and the variation and permanence of their components. T. sordida colonization and dispersal is favored by open areas, mainly pasture lands where many dry trees remain as the result of primitive vegetation destruction. Development of P. megistus occurs near residual forests, and it seems that artificial environment attraction is due mainly to the number of peridomestic dwellings. R. […]

The results of observations made on triatominae bug domiciliation, after house cleaning using chemical substances, are reported. The work was carried out during the period January 1975 to January 1979. The region studied is part of the endemic center formed by the “cerrados” (doy up-land forests) of Central Brazil. Original local bug domiciliation found before house treatment, was composed of Triatoma infestans and Triatoma sordida populations. After desinsectization, surveillance research showed the start and development of a new, thowgh slower, […]

Spontaneous colonies of Triatoma infestans, T. sordida and Rhodnius neglectus developed in experimental fowlhouses were observed for the conditions under which they developed, their variations, permanence, annual cycles and survival. Of nine of these colonies three were mixed, one of them with T. infestans and T. sordida and two with T. sordida and R. neglectus. For all the triatomine species the colonies’ development showed a cyclic rhythm with an increase of the production of adults in the first semester of […]

The results of observations made on triatominae bug domiciliation, after house cleaning using chemicals are reported. The work was carried out in a region beloging to the Tropical Atlantic System of Eastern Brazil considered to be as the dispersal center of the Panstrongyius megistus. The observations were made during the period March 1976 to October 1978, in areas where the original bug domiciliation found before house treatment, was composed by Triatoma infestans and Panstrongylus megistus populations. After desinsectization, surveillance research […]

The results of observations on triatominae bugs in three localities, one of them under to active annual regular surveillance and the other two which had undergone house treatment six months and one and half years before, respectively, are reported. Two of these localities were situated in the dispersal center region of Panstrongylus megistus, and the third in the dispersal center region of Triatoma sordida. At two-monthly periods each area was submitted to dwelling inspection in the search for triatominae bugs […]