Abstract: In order to elucidate the effects of starvation treatment to the oriental armyworm, Mythimna separata (Walker) within 24 h after emergence on the reproduction system and flight system, the ovarian development grade, preoviposition period, thoracic dorsal-longitudinal muscle weight and flight potential of thetreatment moths (starved for 24 h only on day 1 of post-emergence) and the control moths (accessed to honey water throughout adult period) of the oriental armyworm were studied systematically. The results showed that the ovarian development grade of the treatment moths was significantly higher than that of the control. The preoviposition period of the starved moths was significantly shorter than that of the control. Dry weight of the thoracic dorsal-longitudinal muscle in the starved female moths (5.1 mg) was also significantly lower than that in the control (5.86 mg) at 120 h after starvation. The starved moths exhibited lower flight potential than the control. Though the difference was not significant during 72 h after treatment, the flight potential variables in the starved moths were significantly lower than those in the control since 96 h after treatment. At 96 h after treatment, flight distance of the starved moths (22.03 km in average) was significantly less than that of the control moths (42.3 km in average); the flight duration of the starved moths (4.07 h in average) was significantly shorter than that of the control moths (7.99 h in average). All these results indicated that starvation for 24 h on the first day after emergence suppressed the development of flight muscle and accelerated the change from the flight system to the reproduction system in adults of the oriental armyworm.

Key words: Mythimna separata, starvation on day 1 of post-emergence, reproduction, ovarian development flight potential