Abstract: 【Aim】 The oriental fruit moth,Grapholita molesta (Busck) (Lepidoptera: Tortricidae), is a worldwide fruit pest, causing serious loss to fruit productivity. Our study aims to explore the thermal tolerance and adaptability of G. molesta adults after exposure to short-term high temperature. 【Methods】 The survival rate of G. molesta adults exposed to various temperatures (36, 38, 40, 42, 44 and 46℃) for different time durations (0.5, 1, 2, 4 and 8 h), and the effects of shortterm high temperature exposure (heat hardening at 38 or 40℃ for 1 h) on their thermal tolerance, longevity, fecundity, and egg hatchability were investigated. 【Results】 The results showed that the survival rate of G. molesta adults was reduced with the increase of exposure duration to high temperature. The survival rate of G. molesta adults at 42℃ was significantly improved after adults were subjected to heat hardening at 38℃ or 42℃ for 1 h (P<0.05). After treatment at 41℃ for 1 h, G. molesta adults were heat shocked, with longer life span and less fecundity. The further study confirmed that the male adults were greatly affected by high temperature, resulting in the reduction of eggs laid by female adults paired. Nevertheless, there was no remarkable difference in egg hatchability in different treatments though their parents underwent thermal stress. 【Conclusion】 These results suggest that high temperature exceeding 41℃ for 1 h causes negative effects to G. molesta adults, but G. molesta adults have a relatively high thermal tolerance and the potential to adapt to high temperatures.

Key words: Grapholita molesta, temperature, fecundity, longevity, survival rate, thermal stress