Trap captures and species-specific responses (trap specificity) with four different, blends composed of four components of synthetic western obliquebanded leafroller,Choristoneura rosaceana(Harris) (Lepidoptera: Tortricidae) sex pheromone were assessed in British Columbia, using seasonal trap catches of obliquebanded leafroller and the ratio of obliquebanded leafroller toArchips rosanus(L.) (Lepidoptera: Tortricidae). A four-component blend containingZ11-14:0Ac,E11-14:0Ac,Z11-14:ALD, andZ11-14:0H in a 100:2:1:0.75 ratio captured the greatest number of obliquebanded leafrollers and had a degree of trap specificity. In addition, differences in trap captures and the degree of trap specificity also were assessed for eastern (Quebec) and western (British Columbia) populations of obliquebanded leafroller. Comparisons were made using three different blends composed of either three or four components of the obliquebanded leafroller sex pheromone with the ratios 100:2:1:1.5, 100:5:0:5, and 100:2.5:0:2.5ofZ11-14:0Ac,E11-14:0Ac,Z11-14:ALD, andZ11-14: OH. In British Columbia, the four-component blend (100:2:1:1.5)captured the greatest number of obliquebanded leafrollers and had a high degree of trap specificity. In Quebec, no differences in trap captures among the blends were observed. These results suggest that qualitative differences may exist between the sex pheromone of eastern and western populations of obliquebanded leafroller and indicate the need for considering regional differences when monitoring obliquebanded leafroller with commercial synthetic pheromone blends.