Abstract: 【Aim】 Grapholita molesta is a fruit pest that poses a significant threat to fruit production globally. Sex-pheromone-mediated mating disruption technology is a highly specific, efficient, non-toxic, and ecologically beneficial control method. The control efficacy of this technology mainly depends on the dosage of sex pheromones and the density of the mating disruption products. This study aims to explore the accurate use of sex-pheromone-mediated mating disruption technology, and to provide new data support for effectively improving the green control level of G. molesta and realizing the safety of fruit production in China. 【Methods】 In this study, G. molesta adults were treated with the sex pheromone containing four components ［(Z)-8-dodecenyl acetate, (E)-8-dodecenyl acetate, (Z)-8-dodecen-l-ol, and dodecanol］ at five different dosages (0.0131, 0.131, 1.31, 13.1 and 131 mg). The electroantennogram (EAG) responses of unmated and once-mated male adults to different dosages of sex pheromone were measured. The number of mating pairs, mating duration and mating day-old age of female and male adults, as well as the change characteristics of the number of eggs laid per female, number of eggs hatched and egg hatching rate were measured in the environments with different dosages of sex pheromone using an indoor cage method. The rate of mating disruption of sex pheromone to G. molesta and the fruit-boring control efficacy were validated in the field. 【Results】 The EAG response results showed that, as the sex pheromone dosage increased, the EAG response of unmated male adults of G. molesta became stronger, reaching the maximum at the dosage of 13.1 mg. However, the sex pheromone dosage had no significant effect on the EAG response of once-mated male adults. Indoor cage test indicated that the sex pheromone at the dosages of 1.31-131 mg significantly reduced the number of mating pairs between female and male adults compared to the control (n-hexane). Although there were no significant differences in mating duration, mating day-old age, and the number of eggs laid per female between the sex pheromone treatment group and the control group, all the five dosages of sex pheromone significantly reduced the number of eggs hatched and egg hatching rate. When pregnant females were directly exposed to different dosages of sex pheromone, the number of eggs laid per female showed no significant change, but the sex pheromone at the dosages of 0.131-131 mg significantly reduced the number of hatched eggs and egg hatching rate compared to the control. In the field, the sex pheromone at the dosage of 131 mg resulted in significantly higher rate of mating disruption and fruit-boring control efficacy against G. molesta than that at the dosage of 13.1 mg. There was no significant difference in the rate of mating disruption or fruit-boring control efficacy against G. molesta between hanging 60 and 90 mating disruption products per 667 m2.【Conclusion】 Considering both control efficacy and economic cost, a sex pheromone dosage of 131 mg with 60 mating disruption products per 667 m² is suitable for mating disruption technology of G. molesta in the field. These results provide the theoretical basis of mating disruption technology to precisely control G. molesta.

Key words: Grapholita molesta, sex pheromone, olfactory response, mating behavior, dosage effect