关键词: 七星瓢虫, 温度, 设施环境, 生物防治, 年龄-龄期两性生命表

Abstract:  【Aim】 To clarify the effects of high temperature treatment on the growth, development and reproduction of the seven-spot ladybird, Coccinella septempunctata. 【Methods】 Based on the high temperature status of the two representative areas (plant cover and plant upper surface) in the facility environment, the artificial climate chamber was used to simulate the above high temperature environment, and the effects of different high temperatures (37 and 42 ℃) (constant temperatures) and their combinations (variable temperatures) on the growth, development and reproduction of C. septempunctata were determined, and the data of life table parameters such as growth and development, fertility and survival rate were analyzed and processed using software such as the age-stage, two-sex life table TWOSEX-MSChart. 【Results】 The higher the temperature and the longer the duration of the high temperature, the faster the development of C. septempunctata, the shorter the longevity, and the lower the fecudity. Under the constant temperature 42 ℃ and variable temperatures 25-42 ℃, C. septempunctata could not complete development, and its longevity was 3.43 and 4.70 d, respectively; under the constant temperature 37 ℃, C. septempunctata could complete development, but the fecudity was 0, the immature duration was 11.67 d, the adult longevity was 7.75 d, and the body weight of the newly emerged adult was 0.0207 g, which were significantly lower than the corresponding indicators of the control (under the constant temperature 25 ℃) (the immature duration was 17.64 d, the adult longevity was 51.51 d, and the body weight of the newly emerged adult was 0.0277 g, respectively). Under the variable temperatures 25-37 ℃, C. septempunctata could develop and reproduce, but the hatching rate of eggs was 0, the immature duration was 15.16 d, the adult longevity was 22.84 d, the oviposition period was 4.57 d, the fecundity was 41.86 grains/female, the body weight of the newly emerged adult was 0.0220 g, the gross reproductive rate (GRR) was 17.213, the intrinsic rate of increase (r_m) was 0.072 d^-1, the finite rate of increase (λ) was 1.075 d^-1, the net reproductive rate (R₀) was 5.749, and the mean generation time (T) was 21.188 d, all of which were significantly lower than the corresponding indicators of the control, which were 28.28 d, 1 410.52 grains/female, 0.0277 g, 708.110, 0.256 d-1, 1.293 d-1, 673.205, and 25.304 d, respectively. In particular, under the variable temperatures 25-37 ℃, the 3rd instar larval duration of C. septempunctata (2.19 d) was significantly longer than that of the control (1.89 d), while that under the constant temperature 37 ℃ (1.15 d) was significantly shorter than that of the control; the adult pre-oviposition period (APOP) under the variable temperatures 25-37 ℃ was longer than that of the control, but there was no significant difference between them. 【Conclusion】C. septempunctata can’t adapt to the constant temperature 42 ℃ and variable temperatures 25-42 ℃ conditions, can adapt to the constant temperature 37 ℃ and variable temperatures 25-37 ℃ conditions, but it can’t reproduce under the constant temperature 37 ℃ condition, the number of eggs laid is significantly reduced and the eggs can’t hatch under the variable temperatures 25-37 ℃. The results suggest that high temperature can have a significant impact on the reproductive development and reproduction of C. septempunctata, and it is feasible to apply C. septempunctata for pest control under facility conditions, but it is more suitable for use in spring and autumn than in summer.

Key words: Coccinella septempunctata, temperature, facility environment, biocontrol, age-stage, two-sex life table