t. pallidipennis was found naturally infected in localities of domestic, peridomestic and wild areas in the state of morelos, méxico. in agreement with the triatomines high potentiality like vectors of t. cruzi, protozoan that causes chagas' disease and the knowledge of these bugs in méxico, the aim of the present research was to collect triatomines for assessment of t. cruzi infection, to characterize and compare life cycles, identification of feeding preferences and observe indexes of experimental infectivity. seven isolates of t. cruzi were obtained, from differents localities which curves of parasites showed different behaviors. histopathological study, carried out by counting of amastigotes nests, which affected the gastrocnemius muscle and heard was observed. the life cycles of t. pallidipennis was completed in 131 days. the feeding preferences were rats, cats and pigs.