Spathius agrili was released in August 2007 against the emreald ash borer, Agrilus planipennis, at three sites in Michigan. This parasitoid was recovered in substantial numbers at one of the release locations. Studies were conducted in 2008 to assess dispersal away from the release point. Releases continued at more sites in 2008, and we report on the long-term plan to quantify parasitoid establishment and impact on EAB population density and tree health.