The principal sex pheromone ofFeltia jaculifera(Guenée) was identified as (Z)-11-hexadecenyl acetate by electrophysiology, chemical analysis, and behavioral tests. Field traps baited with 10–100 µg of this compound captured manyF. jaculiferamales, but incorporation of ca. 0.05% (Z)-7-dodecenyl acetate in the lure greatly increased numbers taken. Addition also of ca. 0.1% (Z)-9-tetradecenyl acetate gave a still stronger lure. Flight tunnel studies confirmed these compounds' synergistic action.