Abstract:  【Aim】 Protease inhibitor is a low molecular weight protein widely found in plants that inhibits larval development by affecting enzyme activity in insects. This study aims to clarify the effects of mung bean trypsin inhibitor (MBTI) on the growth and development and enzyme activities in Callosobruchus chinensis. 【Methods】 The inhibitory effects of feeding on artificial mung bean containing 2.0% MBTI on the growth and development of C. chinensis were determined by means of artificial inoculation, and the activities of detoxifying enzymes, carboxylesterase (CarE) and glutathione-S-transferases (GSTs), and protective enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), in the larvae fed on artificial mung bean containing different concentrations (0.5%, 1.0%, 1.5% and 2.0%) of MBTI were measured by biochemical methods. 【Results】 After the larvae of C. chinensis fed with 2.0% MBTI, the larval weight and adult emergence rate were significantly lower than those of the control (fed with the artificial mung bean made with the susceptible mung bean variety), being 72% and 55% of that of the control, respectively, and the developmental duration of immature stages was prolonged, being 1.083-fold as long as that of the control. However, MBTI had no significant effect on the number of eggs laid on beans and egg hatching rate. The CarE, GSTs and POD activities in various instar larvae were promoted by the intake of artificial mung bean with different contents of MBTI. However, the activities of SOD and CAT in various instar larvae were inhibited by the intake of artificial mung bean with different contents of MBTI. The inhibitory and promotive effects on the enzyme activities were enhanced with the increase of MBTI content. The CarE, GSTs and POD activities in the 1st instar larvae were most strongly promoted by 2.0% MBTI, being 46.5%, 60.5% and 67.3% of that in the control, respectively. MBTI at the concentration of 2.0% showed the strongest inhibitory effect on the SOD activity in the 4th instar larvae and the CAT activity in the 1st instar larvae, being 80.0% and 47.6% of that in the control, respectively. 【Conclusion】 Mung bean trypsin inhibitor inhibits both the larval weight and adult emergence rate of C. chinensis, results in a relatively prolonged developmental duration of immature stages, and affects the activities of detoxifying enzyme and protective enzyme. Thus, the larvae of C. chinensis can not grow normally.

Key words: Callosobruchus chinensis, mung bean, trypsin inhibitor, growth and development, detoxifying enzyme, protective enzyme