none The rice moth was reared under different regimes of photoperiod using an electric-type light trap as light source only. For the control treatment the larvae received natural light. The cumulative percentage of emergence up to 10, 20 and 30 days after first moth emergence for each treatment ranged from 27.0 apprx 31.0%, 63.0 apprx 87.5% and 68.5% apprx 92.5%, respectively, and no significant difference was found. The amount of eggs produced by 100 females within 1 to 3 days and 4 to 6 days after emergence were 0.52 apprx 0.75cc and 0.15 apprx 0.39cc, respectively, and again no significant difference was found. The results revealed that the emergence and oviposition of the rice moth were not affected when the larvae reared under different photoperiods. Peak of emergence for each treatment was between 10 and 20 days after the first female emergence. Peak of oviposition was within the period of first 3 days after female moth emerged. Therefore, it was concluded that the light trap could be operated the whole day for trapping the parasitoid (Bracon hebetor Say) without any adverse effect on mass rearing of the rice moth.