[Aim]  To investigate the effects of sublethal concentrations of the insecticides abamectin, imidacloprid and beta-cypermethrin on the parasitic behavior of T. chilonis, on  the activity detoxification and protective enzymes in this species, and on levels of mitochondrial respiratory chain complexⅠ(MRCCⅠ), adenosine triphosphate (ATP), reactive oxygen species (ROS) and malondialdehyde (MDA). [Methods]  The effects of sublethal concentrations of the different insecticides on the prey searching, processing time, parasitic efficiency, and maximum parasitic capacity, of T. chilonis were measured and compared, and changes in enzyme activity, MRCCⅠand ATP content were analyzed using the dry film residue method. [Results]  Abamectin, imidacloprid and beta-cypermethrin significantly reduced the effectiveness of prey searching, and reduced overall parasitic efficiency by 54.81%, 20.79% and 11.55%, respectively. Glutathione S-transferase (GSTs), cytochrome P450 (CYP450), carboxylesterase (CarE) and peroxidase (POD) activity all significantly increased after treatment with the three insecticides (abamectin：P = 0.043, P = 0.005, P = 0.022 and P = 0.004, imidacloprid：P < 0.001, P = 0.013, P = 0.017 and P < 0.001, beta-cypermethrin：P < 0.001, P = 0.013, P = 0.002 and P = 0.002). ROS (P = 0.050), MDA (P < 0.001) and MRCCI (P = 0.006) content significantly increased after treatment with abamectin. Superoxide dismutase (SOD) activity significantly decreased (P = 0.050), whereas MDA (P = 0.010) and MRCCI (P = 0.005) content significantly increased after treatment with imidacloprid. Catalase (CAT) (P = 0.034), ROS (P = 0.025), MDA (P = 0.008), MRCCI (P = 0.020) and ATP (P = 0.004) content significantly increased after beta-cypermethrin treatment. [Conclusion]  Sublethal concentrations of abamectin, imidacloprid and beta-cypermethrin, significantly reduced the prey searching efficiency and parasitic ability of T. chilonis (parasitic ability：20 grain：P = 0.004; 30 grain：P < 0.001; 50 grain：P < 0.001; 60 grain：P < 0.001; 100 grain：P = 0.001; 120 grain：P = 0.003; 150 grain：P = 0.001). Treatment with these pesticides also increased detoxification enzyme activity, and affected both protective enzyme activity and ROS, MDA, MRCCⅠand ATP content, in this species.