关键词: 麦长管蚜, UV-B辐射, 重金属, 镉, 双重胁迫, 生命表

Abstract: 【Aim】 To explore the effects of the dual stress of UV-B and cadmium on the growth, development and fecundity of  Sitobion avenae (Fabricius), and to determine whether there is the interaction between UV-B and cadmium. 【Methods】 The age-specific life table was employed to explore the effects of the co-stress of different intensities of UV-B (0, 0.1, 0.2 and 0.7 mW/cm²) and concentrations of cadmium (0, 20, 40, 80 and 160 mg/kg) on the growth, development and fecundity of S. avenae in the laboratory. 【Results】 The life table parameters of S. avenae were adversely influenced by the dual stress of UV-B and cadmium, and they were affected more severely by UV-B than by cadmium stress. In addition, there are significant interactions between the stress of UV-B and cadmium. In particular,under the same concentration of cadmium treatments, the effects of UV-B on the intrinsic rate of increase (r), the finite rate of increase (λ), the net rate of increase (R₀), fecundity (F), oviposition duration and adult longevity of S. avenae showed a trend of first decreasing and then increasing, and fell to the minimum value under the intensity of 0.2 mW/cm² of UV-B. However, the mean length of a generation (T) revealed an adverse trend, namely showing a trend of first increasing and then decreasing, and reached the first peak at the intensity of 0.1 mW/cm² of UV-B. Under the same intensity of UV-B radiation, with the increase of the concentrations of cadmium, all life table parameters of S. avenae displayed fluctuation. Moreover, the parameters of r, λ, R₀, F, oviposition duration and adult longevity of S. avenae in the combined treatments were significantly lower than those in the treatments only exposed to different concentrations of cadmium. However, the parameter  T revealed a reverse result. Every peak point or minimum value of all above life table parameters of S. avenae exposed to the dual stress of UV-B and cadmium was somewhat earlier than that only exposed to different concentrations of cadmium. 【Conclusion】 The growth, development and fecundity of S. avenae were significantly affected by the stress of UV-B and cadmium. Moreover, the influences will be intensified when the two factors act in combination, suggesting that these two factors have significant interactions.

Key words: Sitobion avenae, UV-B radiation, heavy metal, cadmium (Cd), dual stress, life table