Traps baited with live virgin females or trans-8, trans-10-dodecadien-1-ol, the synthetic sex pheromone ofLaspeyresia pomonella(L.), were used to determine population levels of this pest in a sprayed and in a nonsprayed orchard. The syntheticpheromone traps captured far more male codling moths than those baited with virgin females for most of the season. In August, male captures were slightly higher in the female-baited traps.In the sprayed orchard, the average weekly male codling moth capture from femalebaited and pheromone traps per trap site was less than 2 except for one period, August 17, when the average was 2.0. A few recent codling moth larval entries were noted in late August, and the grower applied a spray of azinphosmethyl on September 6. This was the only codling moth spray applied in contrast to a 3-spray program the previous year. At harvest, the codling moth infestation was less than 0.5% injured fruit.In contrast to the sprayed orchard, female-baited traps in a nonsprayed orchard captured an average of 11.3 male moths per trap per week. The infestation in this orchard averaged 12.7% injured fruit at harvest.These data indicate that codling moth pheromone traps are useful for estimating native populations and for indicating the need for chemical control.