[The prevalence, infection indices and feeding habits of the Triatominae captured in an area of epidemiological surveillance].

Prevalence of triatomines and their infection by Trypanosoma cruzi, were studied during 1974-1981, in the Administrative Region of Campinas, São Paulo, Brazil. This investigation was continued (1982-1986), blood meal tests with bird, marsupial, rodent and human antisera having been added. Panstrongylus megistus, predominant in the region, whose winged instars are often found infected by T. cruzi in inhabited houses, displayed and alimentary eclecticism. From a sample of 7,785, 14.78 percent reacted positively with human antisera. A similar, but less marked behaviour was observed in Rhodnius neglectus. Triatoma sordida, the second most important species in the Region, was neither demonstrated to be feeding on humans nor to be infected by T. cruzi. Changes in their natural habitat probably caused sharp rises in T. arthurneivai populations in the human dwellings. The capture of three specimens of Microtriatoma borbai marks the first occurrence of this species in the State São Paulo. "Focus investigation" in areas in the surveillance phase can detect triatomines in the process of domiciliation.