Abstract: To evaluate an artificial liquid diet of Orius similis Zheng, the nymph and adult of O. similis were fed on the artificial diet for two generations continuously using cotton aphids as the control, and their developmental and reproductive indexes at different stages were investigated. The results showed that the durations (22-23 days) of the two consecutive generations of O. similis were not significantly different from that of the control (21 days), which suggested that the diet could well meet the nutritional need of the nymph of O. similis for growth and development. However, the obtainable rate of the adult of O. similis fed on the cotton aphids could achieve 63%, which was prominently greater than those of the two consecutive generations of O. similis fed on the artificial liquid diet, which were 45% and 43%, respectively. There were no significant differences in the period of pre-oviposition, the fecundity and longevity of the adult of O. similis between the treatments and the control. But the significant difference was observed in the period of oviposition between the treatments and the control, which are about 13-16 days for the treatments and 20 days for the control, respectively. These results suggested that the artificial liquid diet could also well meet the nutritional need of adult O. similis for reproduction. 

Key words: Orius similis, artificial liquid diet, mass rearing, biological control, growth and development, reproduction