Populations of wasps,Vespulaspp., on a 22-acre peach orchard near The Dalles, Oregon, were successfully depressed during the summers of 1969 and 1971 with traps containing the highly potent specific lures, 2,4-hexadlenyl butyrate or heptyl butyrate placed around the orchard' periphery. Moreover, the yellowjackets, mostlyVespula pensylvanica(Saussure), were reduced below troublesome levels within four days after the traps were placed. In 1969 about 200,000 wasps were captured in 114 carton traps and four large Malaise traps; in 1971 about 65,000 wasps were taken in seventy 87-oz (2.5-liter) plastic-container traps.