AbstractSex attraction studies were carried out to investigate the mate-finding behaviour of invasiveVespula vulgaris(Linnaeus) (Hymenoptera: Vespidae) wasps. Delta traps were baited with live, caged males, and gynes (virgin queens) ofV. vulgaristo determine whether either sex produced a long-range sex attractant. Traps baited with gynes caught 71 males, while the controls and live-male wasp baited traps did not catch gynes. Wind tunnel trials were performed to verify if the signal produced by the gynes was chemical in nature. First,V. vulgarismales were flown to live caged gynes, where more than half of the males tested flew upwind in a zigzagging pattern and made contact with caged gynes. Males were also flown to hexane rinses of gynes and flew upwind in a zigzagging pattern towards the gyne extract, although none made contact with the cotton roll stimulus. The results presented here demonstrate conclusively thatV. vulgarisgynes produce a sex pheromone.