An area with natural foci of Triatoma arthurneivai Lent & Martins, 1940, is recorded at the place of Itupararanga in the county of Salto de Pirapora, São Paulo State, Brasil. These foci were represented by ecotopes placed between sliced stones, similar to the ones previously described in surrounding regions. An association with lizards Tropidurus torquatus Wied. it was suspected to be of feeding nature. Nevertheless the triatomids showed to eat quickly and intensively white mice, under laboratory conditions. Beside this, the experimental infection by Trypanosoma cruzi was easily obtained. These data led the authors to suspect that T. arthurneivai may play some transmission role in nature.