Surveys for Aedes aegypti were conducted in Lima, Peru in 2004 and 2005. Simple random sampling was used in house selection, and two-stage sampling was used in block selection. A total of 19,713 houses were surveyed covering a total area of 3.079 Km2 . The spatial distribution of the mosquito and associated environmental risk factors will be presented. Additionally, the effects of pyriproxyfen were tested against a local population of Ae. aegypti in the Amazonian city of Iquitos, Peru. Results indicate that, when applied to late instars, pyriproxyfen prevented adult emergence at extremely low concentrations (LC50, 0.012 ppb). There was no adult emergence from water sampled from storage tanks that had been seeded with the equivalent of 50 - 83 ppb (AI) pyriproxyfen. Additional laboratory studies suggest that water treated with pyriproxyfen might act as sinks for mosquito reproduction and/or such sites might act as dissemination sources for the horizontal transfer of larvicides to new environments by mature females.