Both the (Z) and the (E) pheromone strains of Ostrinia nubilalis (Hubner) were found to occur sympatrically in North Carolina. Traps baited with a blend of 97%Z and 3%E 11-tetradecenyl acetate (11–14: Ac) caught significantly more male moths than did traps baited with a 4%Z:96%E blend. An intermediate number of males was caught in traps baited with blends of 50%Z:50%E or 35%Z:65%E 11–14:Ac. Correlations between the numbers of moths caught in traps baited with the different blends were not consistently significant. The sex pheromone baited traps were far less effective than a BL trap for monitoring seasonal activity of the European corn borer moth population.