Of 21 wetlands in the Minneapolis-St. Paul area that supported similar densities of Coquillettidia perturbans larvae, 7 wetlands were treated with Altosid methoprene pellets at 5.6 kg/ha on May 28, 1992, 7 were treated with Altosid XR extended residual methoprene briquets at 1 briquet/9.3 m2 in March 1992, and the final 7 remained untreated. Emergence data collected from May 28 through late August in all sites indicated pellet and briquet treatments achieved greater than 90% control.