Abstract: Photoperiodic cues play important roles in insect environmental adaption, and insects can regulate their physiological processes to adapt environmental changes through perceiving the changes of photoperiod. In order to investigate the mechanisms of physiological adaptation to photoperiod changes, we detected the activities of catalase (CAT), superoxide dismutase (SOD), Na⁺K⁺-ATPase and lactic dehydrogenase (LDH) of overwintering adults of Chrysoperla sinica (Tjeder) in the progress of diapause termination under the long (15L∶9D) and short photoperiods (9L∶15D) in the laboratory conditions. The CAT activity of both female and male adults reached a peak at 5 d after treatment and was higher under the long photoperiod than under the short photoperiod, with significant difference at 15 d (P<0.05) and 20 d after treatment (P<0.005). However, the CAT activity was significantly lower under the long photoperiod than under the short photoperiod at 10 d after treatment (P=0.005). The SOD activity of female adults was significantly lower under the long photoperiod than under the short photoperiod at 5 d after treatment (P<0.001). The SOD activity of male adults under the long photoperiod was significantly higher at 5 d (P=0.04), 15 d (P<0.001) and 20 d after treatment (P=0.003) than that under the short photoperiod. The LDH activity decreased with the time under the two photoperiods, and the activities in both treatments were significantly lower than that in adults treated for 0 d (P<0.001). The results indicated that the differences of enzyme activities of Ch. sinica under the long and short photoperiods may be the main physiological factor triggering the content of bio-chemical substances in the adult body and reproductive status during the adult diapause termination.

Key words: Chrysoperla sinica, overwintering adult, diapause termination, photoperiod, catalase (CAT), superoxide dismutase (SOD), Na⁺K⁺-ATPase , lactic dehydrogenase (LDH)