The gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), has been gradually expanding its range in North America since its accidental release approximately 135 years ago. Under the USDA Cooperative Management Program Slow-the-Spread (STS), colonies ahead of the population front are targeted for eradication to prevent their growth and coalescence, which could accelerate gypsy moth spread. The principle control tactic in STS is mating disruption, in which synthetic sex pheromone is aerially applied to foliage to interfere with the male moth’s ability to locate females. We were motivated by a previous study that suggested potential residual effects of this tactic in subsequent years beyond what was previously thought. We thus used data collected under STS in Wisconsin, Illinois, Indiana, Ohio, West Virginia, Virginia, and North Carolina from 1996-2004 to evaluate the effects of mating disruption on colony abundance one and two years following treatment.