The monoterpenoid citral synergized the electroantennogram (EAG) response of male Grapholita molesta (Busck) antennae to its main pheromone compound Z8–12:OAc. The response to a 10-µg pheromone stimulus increased by 32, 45, 54, 71 and 94% with the addition of 0.1, 1, 10, 100 and 1,000 µg of citral, respectively. There was no detectable response to 0.1, 1, or 10 µg of citral; the response to 100 and 1,000 µg of citral was 31 and 79% of the response to 10 µg of Z8–12:OAc. In a flight tunnel, citral affected the mate-seeking behavior of males. There was a 66% reduction in the number of males orientating by flight to a virgin calling female when citral was emitted at 1,000 ng/min ≈1 cm downwind from a female. Pheromone and citral induced sensory adaptation in male antennae, but citral did not synergize the effect of pheromone. The exposure of antennae to 1 ng Z8–12:OAc/m³ air, 1 ng citral/m³ air, 1 ng Z8–12:OAc 1 ng citral/m³ air, or to 1 ng Z8–12:OAc 100 ng citral/m³ air for 15 min resulted in a similar reduction in EAG response of 47–63%. The exposure of males to these same treatments for 15 min had no effect on their ability to orientate to a virgin calling female in a flight tunnel. The potential for using citral to control G. molesta by mating disruption is discussed.