Abstract: 【Aim】 To clarify the effects of light intensity on the growth, development and fecundity of Megacopta cribraria and to further explore its adaptation to light environment. 【Methods】 Under the conditions of temperature 24±1℃, relative humidity 60%±10% and photoperiod 16L∶8D, the growth, development and reproduction indexes of M. cribraria on soybean host plant, including developmental duration of each developmental stage, adult longevity, survival rate, nutrient accumulation efficiency of the nymphal stage, under different light intensities (500, 2 500, 4 500, 6 500, 8 500 and 10 500 lx) were determined, and the effects of light intensity on population trend changes were further analyzed by using life table method. 【Results】 Light intensity had significant effects on the duration of various developmental stages, survival rate and adult fecundity of M. cribraria. The developmental duration of each developmental stage had a tendency to shorten with the increase of light intensity. The developmental rate of each developmental stage and the nutrient accumulation efficiency of the nymphal stage were significantly positively correlated with light intensity. The relationships between the developmental rate of each developmental stage and light intensity were as follows: V₁=0.129968exp(0.011310L_I) (egg stage, R²=0.610, P<0.0001),  V₂=0.000767L_I+0.014182 (nymphal stage, R²=0.980, P<0.0001), and V₃=0.019000L_I^0.418000(preoviposition period of female, R²=0.837, P<0.0001). The nutrient accumulation efficiency of nymphal stage and light intensity fitted the cubic function model y=0.0004x³-0.0064x²+0.0361x+0.0660 (R²=0.983, P<0.0001). The population trend index I increased significantly with the increase of light intensity. The M. cribraria population could not complete the reproductive process when the light intensity was lower than 2 500 lx. 【Conclusion】 Light intensity significantly affects the growth and fecundity of M. cribraria. Higher light intensity (10 500 lx) is more conducive to its population growth, while lower light intensity (≤2 500 lx) will lead to gradual extinction of the population.

Key words: Megacopta cribraria, light intensity, life table, developmental duration, nutrient accumulation efficiency, population trend