(Z)-9-tetradecenyl formate (Z-9-TDF) had no disruptive effect inSpodoptera littoraliswhen released at high rates from 4 evaporators located at 3.5 m radius from the attractant. At this distance, (Z)-9-tetradecenyl acetate (Z-9-TDA) was an effective disruptant, somewhat less effective at 7 m radius and totally ineffective at 32 m. At 32 m, (Z,E)-9,12-tetradecadienyl acetate (Z,E-9,12-TDDA) was also ineffective. However, (Z,E)-9,11-tetradecadienyl acetate (Z,E-9,11-TDDA), the synthetic sex pheromone ofS. littoralis, was an effective disruptant even when released 44.5 m away from the attractant: 80–90% disruption was achieved at release rates of 2 to 4 mg/h/ha.