Abstract: [Objective] The aim of this study is to reveal the population dynamics of Grapholitha molesta (Lepidotera; Tortricidae) and control effect by sexual pheromone on mating disruption of the pest in the apple orchards with the non-bagged-fruit cultivation pattern.[Method] The occurrence dynamics of G. molesta in the field and the rate of bored fruits in non-bagged-fruit cultivation orchards were monitored via sexual pheromone inducer in Yantai, Weihai and Tai'an respectively. According to the occurrence dynamics, the control effect of sexual pheromone was explored by releasing the sexual pheromone in eclosion prophase of the overwintering generation, the first generation and the second generation.[Result] The result showed that the adults of G. molesta in 2017 emerged from mid or late March to early April in Yantai, Weihai and Tai'an, and ended in early October. There were five obvious occurrence peaks, which were concentrated from July to September. The year-round number of G. molesta caught by sexual pheromone (ranging from 213 to 1837 insects per trap) in non-bagged apple orchards of three regions was significantly lower than that in bagged orchards (ranging from 729 to 3715 insects per trap) (P<0.05). However, the rate of bored fruits in non-bagged apple orchards (ranging from 3.38% to 6.13%) was significantly higher than that in bagged orchards (ranging from 0.13% to 0.50%) (P<0.05). In bagged apple orchards, sexual pheromone released in eclosion prophase of the overwintering generation, the first generation and the second generation all exhibited obvious disruption effect on the mating action of G. molesta male adults, however, the rates of mating disruption in different periods were significantly different (ranging from 87.28% to 99.80%) (P<0.05). In the larvae damaging peak of G. molesta (the fifth generation) from September 11 to October 8, the control effect of sex pheromone that was released before the first generation and the second generation eclosion (respectively being 92.89% and 95.53%) of Grapholitha molesta were significantly higher than that was released before the winter overwintering eclosion (81.77%) (P<0.05).[Conclusion] There was no significant difference in the occurrence dynamics, peak period of adults and duration between the bagged and non-bagged apple orchards in Yantai, Weihai and Tai'an, but the damage of G. molesta in non-bagged apple orchards was significantly more serious than that in bagged orchards. In non-bagged orchards, the combination of sex pheromone and chemical pesticide was more effective than single chemical pesticide, and the sex pheromone released before the first generation and the second generation eclosion of G. molesta obtained the best control effect.

Key words: The apple orchards with non-bagged-fruit cultivation pattern, Grapholitha molesta, population dynamics, sexual pheromone