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.
American trypanosomiasis; Xenodiagnosis; Rhodnius neglectus; Triatoma infestans; Trypanosomiasis; Didelphis; Trypanosoma cruzi