Abstract: The influences of temperature (11℃, 16℃, 21℃, 26℃, 31℃) and photoperiod (16L:8D, 14L:10D, 12L:12D, 10L:14D, 8L:16D) on diapause of Delphastus catalinae (Horn) were determined in the laboratory. The results showed that the diapause of D. catalinae was significantly affected by temperature, photoperiod, and the interaction between temperature and photoperiod. Low temperature and short daylight induced the adult diapause. At 26℃ and 31℃, none of the five measured photoperiods could induce diapause. While at 11℃, 16℃ and 21℃, adult diapause rate showed an increasing trend with decreasing temperature or shortening daylight. The optimum conditions to induce diapause were 11℃ and photoperiods 8L:16D. The 95.4% of adults reared at 11℃ and photoperiods 10L:14D for 40 days would enter a stable diapause state. It was also found that the pre-oviposition period of diapause adults was prolonged with decreasing temperature or shortening daylight. The conditions of 11℃ and photoperiods 8L:16D were favorable for the maintenance of diapause duration of diapause and the prolong of pre-oviposition period, whereas the conditions of 21℃ and photoperiods 14L:10D accelerated the termination of diapause and shortened the pre-oviposition period.

Key words: Delphastus catalinae, diapause, temperature, photoperiod