In an air permeation test in a pear orchard in 1975, 98% disruption of trap capture was achieved for 7 wk with the antipheromone of the codling moth,Laspeyresia pomonella(L.), (E,E,)-8,10-dodecadien-1-olacetate, permeating the test area at an initial rate of 127 mg h−1ha−1and decreasing to a final rate of 62 mg h−1ha−1. When the antipheromone and the sex pheromone, (E,E,)-8, 10-dodecadien-1-ol, were compared for disruption efficiency in an apple orchard in 1976, a minimum evaporation rate of 25 mg h−1ha−1of the antipheromone and 15 mg h−1ha−1of the sex pheromone were required to effect 98% disruption of trap capture.