Abstract: 【Aim】In high or low temperature environment, insects enter a reversible coma state due to the temporally shutdown of neural and muscular systems. Extreme temperatures beyond the threshold to induce chill- or heat-coma state and prolonged coma state could result in the death of insects. This study aims to explore the chill- and heat-coma states of two parasitoid wasps Trichopria drosophilae and Pachycrepoideus vindemiae, so as to improve our knowledge of how climate change affects parasitoid wasps. 【Methods】 We observed the time to enter and recover from coma states of T. drosophilae and P. vindemiae adults newly emerged within 24 h at the low temperature of 4 ℃ and high temperatures of 38 and 42 ℃, the proportion of individuals with mobility recovered at 25 ℃ after 60- and 120-min of coma treatment. The longevity of individuals surviving at low and high temperatures was counted. 【Results】T. drosophilae adults entered chill-coma state sooner than P. vindemiae adults under 4 ℃ environment and required longer time to recover from immobility. All T. drosophilae adults lost mobility under 38 and 42 ℃ environments, 27% of the individuals died after 60- and 120-min coma at 38 ℃, and 15% and 38% of the individuals died after 60- and 120-min of coma at 42 ℃, respectively. By contrast, none of P. vindemiae adults lost mobility in 38 ℃ environment while 42 ℃ treatment rendered 35% of adult P. vindemiae motionless and all of those lost mobility for 60- and 120-min died after the heat treatment, indicating that P. vindemiae adults are less likely to survive under high temperature stress via heat-coma state. We also discovered that the adult longevity of the two parasitoid wasps recovered from chill-coma was not affected, yet the adult longevity of the two parasitoid adult wasps recovered from heat-coma was significantly reduced, and T. drosophilae adults suffered a greater reduction in longevity.【Conclusion】 These results suggest that P. vindemiae adults keep active for a longer period of time and have a smaller decrease in longevity than T. drosophilae adults in extreme temperature environment. These results are helpful in designing biocontrol protocols using the studied two parasitoid wasps to reduce the damage by Drosophila flies in changing climate.

Key words: Climate warming, extreme temperatures, temperature adaptation, biological control; Drosophila parasitoid wasps