matsuone (1), female sexpheromone of Matsucoccus resinosae pine scales, were convergently synthesized in high optical purities. The absoluteconfiguration of the natural product has been assigned as (2E, 4E, 6R, 10R)-4,6,10,12-tetramethyltridecan-2,4-dien-7-one. Bioassays with M. resinosae using these stereoisomers reveal that the unnatural (6R, 10S)-isomer mimics the natural pheromone.