Abstract
The role of the sex pheromonal components (Z)-9-tetradecen-1-ol acetate ((Z)-9-TDA) and (Z)-11-tetradecen-1-ol acetate ((Z)-11-TDA) in sexual isolation between the smaller tea tortrix (STT) and the summer-fruit tortrix (SFT) was evaluated. Release rates of the pheromonal components from virgin females were almost equal (1×10-2 μg/female/night) between the two species. The ratio of the two components, (Z)-9- and (Z)-11-TDAs, was 63 : 37 in STT and 82 : 18 in SFT. Under laboratory conditions, male moths of each species were sexually stimulated more strongly by teh synthetic mixture of conspecific ratio. The difference in the male responses of each species to the two synthetic mixtures was amplified by the difference in the mating times between the two species. Species-specific attraction by virgin females in a field cage, however, was explained by neither the difference in the ratio of the two pheromonal components nor the difference in the time of mating. Intensity and species-specificity of attractiveness of virgin females in comparison with the synthetic mixtures suggested the presence of at least one additional pheromonal component in each species.