Abstract: Peristenus spretus Chen et van Achterberg is one of the dominant parasitoids of Apolygus lucorum (Meyer-Dür), and has been applicated for field biological control of A. lucorum in orchards, tea plantations and agricultural fields. In order to clarify the optimal photoperiod and temperature conditions for the diapause induction of P. spretus, two temperatures (15 ℃, 19 ℃ ), compared with three photoperiods 12L:12D, 10L:14D, 8L:16D were set up under laboratory conditions in this experiment, and determined the diapausing pupae formation of P. spretus under the different combinations of temperatures and photoperiods. The results showed that temperature and photoperiod acted together in developmental period and induction of diapause in P. spretus. There was no significant difference in the developmental period under different photoperiodic conditions, and the developmental period of egg-larvae ranged from 30.40 to 33.60 d at 15 ℃, and was shortened to 18.80 to 19.40 d at 19 ℃ . There was no significant difference in diapause rate induced by 15 ℃ combined with different short light durations. The induced diapause rate increased significantly with the increasing in photoperiod (light duration) at 19 ℃ .Photoperiod 12L:12D was more effective in the diapause induction in P. spretus. But at 19 ℃, the egg-larval developmental period of P. spretus inside A. lucorum nymphs was shorter. In conclusion, the combination of photoperiod 12L:12D and 19 ℃ could induce the higher proportion of P. spretus to enter into diapause faster, which was the best condition for the production of diapause pupae of this parasitoid. The above results provide important basic data for the large-scale production, shelf-life extension and large-area application of P. spretus as a natural enemy for controlling A. lucorum.

Key words: Peristenus spretus, developmental period, temperature, photoperiod, diapause