Sexual behavior of male moths after prolonged exposure to the 1-ng pheromone/m³ air previously measured in orchards treated with pheromone for mating disruption was examined in a flight tunnel. The exposure of Grapholita molesta (Busck) to 1-ng (Z)-8-dodecen-l-yl acetate (Z8–12:OAc) /m³ air for 15 min had no effect on their ability to fly upwind to a conspecific, virgin calling female. After 30 min of exposure, males exposed to a control treatment were 1.4× more likely orient to a female than males exposed to pheromone-treated air. Some G. molesta males retained the ability to orient to a female after a 30-min exposure period when the aerial concentration of Z8-12:OAc was increased 500,000× to 0.5 gm/m³. Prolonged exposure to Z8–12:OAc did not affect response to a synthetic pheromone lure. The time required to initiate behavioral responses to a female or a lure was not affected by pheromone exposure. Male Choristoneura rosaceana (Harris) exposed to a control treatment for 15 min were 38.5× more likely to orient to a conspecific, virgin calling female than males exposed to 1-ng (Z)-11-tetradecen-1-yl acetate (Z11-14:OAc)/m³ air for 15 min. After 30 min of exposure males were unable to fly upwind to a female. Males exposed to a control treatment for 15 min were 4.3× more likely to fly upwind to a synthetic pheromone lure than males exposed to 1-ng Z11–14:OAc/m³ air for 15 min. The time required to initiate behavioral responses to a female or a lure was not affected by exposure to pheromone.