The efficacy of technical pyriproxyfen and diflubenzuron was evaluated at the laboratory level against Aedes aegypti, where we achieved adult emergence inhibition (EI50) values of 0.048 and 1.59 ppb (microg/liter), respectively. We compared these data with values obtained for temephos. We prepared emulsifiable concentrate formulations of pyriproxyfen and diflubenzuron in the laboratory and obtained EI50 values of 0.01 and 0.02 ppb, respectively. We also obtained 100% adult emergence inhibition with 0.1% slow-release sand formulations of pyriproxyfen and diflubenzuron. In a simulated field study, the granular sand formulations of pyriproxyfen, diflubenzuron, and temephos remained active for over 4 mo. In a field study, a 0.2% granular formulation of diflubenzuron and 1% temephos showed a similar performance.