vector control strategies against indigenous species is not easy, due to their capacity to reinvade treated premises from sylvatic ecotopes. between august 1996 and december 1997 we conducted a study on reinfestation of houses after spraying in a county in the state of ceará. of 277 houses examined, 113 (40.8%) were infested (21.7% intradomiciliary and 35.4% peridomiciliary). of the 433 triatominae collected, 207 were triatoma brasiliensis (49% of which intradomiciliary, with a mean of 1.8 insects/house) and 226 were triatoma pseudomaculata (97% peridomiciliary). the age structure of the two indicated a univoltine development cycle for t. brasiliensis and two cycles per year for t. pseudomaculata. four months after spraying with deltamethrin sc 25mg ia/m2, 9.7% of the houses were still positive, mainly with peridomestic infestations. intradomiciliary wall bioassays showed persistence of the insecticide up to 9 months after spraying. considering the high potential for recolonization of treated premises from sylvatic foci, we propose an operational strategy combining traditional evaluations and community-based surveillance with increased selective interventions and community education.