Abstract: 【Aim】 This study aims to explore the effects of momordicin I on the growth and related enzyme activities of the experimental population of Ostrinina furnacalis(Güenée). 【Methods】 The effects of momordicin I on the larval weight gain, developmental duration, survival rate and fecundity of O. furnacalis were investigated by adding the compound to the artificial diet provided to O. furnacalis larvae under laboratory conditions. The life table was used to evaluate the control effects of momordicin I on the experimental population of O. furnacalis. The effects of momordicin I on activities of trehalase, alkaline phosphatase and acid phosphatase in O. furnacalis larvae were determined. 【Results】 After the 3rd instar larvae of O. furnacalis were fed with the artificial diet containing 0.25, 0.5, 1.0, 2.0 and 4.0 mg/g momordicin I for 3 d, their survival rates decreased and the LC₅₀ value was 3.2 mg/g. Momordicin I had an apparently inhibitory effect on the body weight gain of O. furnacalis larvae. After the larvae were fed with the artificial diet containing 4.0 mg/g momordicin I for 1, 2 and 3 d, their body weight gain was inhibited by 76.87%, 78.24% and 79.94%, respectively, and the developmental duration of the treated larvae was significantly longer than that of the control group. The pupal duration and adult longevity of the treated larvae were not significantly different from those of the control, while the fecundity of adults in the treatment groups was significantly lower than that of the control. The 4.0 mg/g momordicin I in the artificial diet inhibited the fecundity of adults by 73.55%. Momordicin I in the artificial diet inhibited the activities of trehalase, alkaline and acid phosphatase in O. furnacalis larvae. At 24, 48 and 72 h after the larvae were fed with the artificial diet containing momordicin I, the IC₅₀ values of the trehalase activity were 3.8, 2.9 and 4.9 mg/g, while those of the alkaline phosphatase activity were 3.1, 2.6 and 1.5 mg/g, and those of the acid phosphatase activity were 3.3, 1.9 and 3.6 mg/g, respectively. 【Conclusion】 These results suggest that momordicin I inhibits the population growth and fecundity of O. furnacalis, and its inhibition on the activities of trehalase, alkaline and acid phosphatase of larvae may be a major mechanism of action.

Key words: Ostrinia furnacalis, momordicin I, population control, trehalase, phosphatase