Abstract:Grapholitha molesta Busck is an important pest on pear and peach trees. In order to promote the non-environmental-pollution pest control in the orchard, scale control over G.molesta with mating disruption of sex pheromone was studied in peach and pear orchards in Laiyang, Shandong Province in 2010. It was suggested that the number of G.molesta in treated peach and pear orchards was lower than that in untreated orchards. The number of G.molesta decreased and the rate of mating disruption increased with the increment of pheromone dispensing devices in the orchards. The rates of mating disruption in different peach orchards with 450, 900 and 1350 pheromone dispensing devices per hectare were 67.80%, 80.14% and 89.29% respectively, while in pear orchards the rates were 84.17%, 93.41% and 98.17%. The rates of infested fruits in both treated peach and pear orchards were lower than that in untreated orchards. The control effects of pheromone dispensing devices on G.molesta ranged from 40.34% to 73.57% in treated peach orchards, and from 54.24% to 92.38% in treated pear orchards, indicating that the control effect on G.molesta in treated pear orchard was higher than that in peach orchards.