Abstract: 【Aim】 To elucidate the effects of temperature and humidity on the growth, development, reproduction, and antioxidant enzyme activities of Cacopsylla chinensis. 【Methods】 The duration, number of eggs laid per female and survival rates of various developmental stages of C. chinensis on Pyrus betulifolia under five relative humidity (RH) levels (15%, 35%, 55%, 75% and 95%) were measured. An age-stage two-sex life table was constructed to calculate the survival rate, fecundity, life expectancy, reproductive value and population parameters. Under the conditions of different temperature and humidity combinations (16, 24 and 32 ℃ in combination with RH 15%, 55% and 95%), the survival rates of C. chinensis at different developmental stages were observed and determined, and the activities of the antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the 4th instar nymphs and 2-day-old adults of C. chinensis were measured using turbidity method. 【Results】 RH ranging from 15% to 95% significantly influenced the egg duration, total nymphal duration, adult longevity, pre-oviposition period and number of eggs laid per female, but did not affect the generation time T. Under RH 55% and 75%, the number of eggs laid per female, intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R₀) were significantly higher than those under the other humidity conditions. At 24 ℃, the egg hatching rates of C. chinensis under three RH levels (15%, 55% and 95%) were significantly higher than those at 16 and 32 ℃. The survival rates of the 1st-2nd, 3rd and 4th instar nymphs at 24 ℃ were significantly higher than those at 16 and 32 ℃ under three RH levels. The survival rate of the 5th instar nymphs under the condition of 16 ℃ and RH 55% was significantly higher than that under the condition of 24 ℃ and RH 55%. The adult survival rate was the highest at 16 ℃ across all RH levels, and was the lowest under the condition of 32 ℃ and RH 15%. Under the condition of 24 ℃ and RH 55%, the activities of CAT, SOD and POD in the 4th instar nymphs and 2-day-old adults of C. chinensis remained stable at low levels. 【Conclusion】 Humidity affects the duration of various developmental stages of C. chinensis, but has no significant impact on its entire generation time. RH 55% and 75% are the suitable humidity levels for the reproduction of C. chinensis and the condition of 24 ℃ and RH 55% is conducive to its survival.

Key words: Cacopsylla chinensis, humidity, temperature, growth and development, reproduction, two-sex life table, antioxidant enzymes