Abstract: In this paper, the titre and precise ratio of multi-components of Ancylis sativa Liu sex pheromone were determined by using analytical technique of single sex pheromone gland. The results showed that: (1)the female sex pheromone contained two isomers, i.e. E9-12∶Ac and Z9-12∶Ac, (2) the sex pheromone production of females had a diel periodicity. The female moths began to produce sex pheromone at the onset of the scotophaes and the quantity increased gradually. Pheromone production peak occurred at the 6.5 hour of the second scotophase, (3) the pheromone titres released by females of various generations are different. The pheromone titre released by females of the overwintering generation or the second generation was much higher than that of the first generation, but the ratios of the 2-isomeric components in different generations were the same.

Key words: Ancylis sativa Liu, sex pheromone, chemical communication system