The ability of wild male European corn borer (ECB), Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), to aggregate to both live female ECB and pheromone lures in Bt-corn fields was examined over two summers during the second generation ECB flight in Rosemount, Minnesota. Each year six Hartstack pheromone traps were placed in a Bt-corn field at varying distances to the nearest refuge field (min 30m, max 630m). All traps on a given day were baited with either pheromone lures or lab-reared ECB females. Male ECB catches were counted on each day of the second generation flight. There were no significant differences either in absolute number or in proportion of moths caught per trap by distance from refuge. Since 630m is approximately 0.4 miles, this data supports the resistance management requirement of planting a refuge within a half mile of a Bt-corn field, and leaves open the possibility of extending this distance further.