The geometric isomers (E,E)-, (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1- yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males of Cydia and Grapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds. Pammene, as well as other Grapholita and Cydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini, Hedya, Epiblema, Eucosma, and Notocelia trimaculana were also attracted to 8,10-dodecadien-1-yl acetates, but several other Notocelia to 10,12-tetradecadien-1-yl acetates. The female sex pheromones of C. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella and Notocelia roborana were identified. (E,E)- and (E,Z)-8,10-dodecadien-1-yl acetate are produced via a common E9 desaturation pathway in C. splendana. Calling C. nigricana and C. fagiglandana females are attracted to wingfanning males.