印楝素对柑橘园柑橘全爪螨自然种群的控制作用

针对我国柑橘园柑橘全爪螨种群严重发生的现状，本文应用均匀设计，通过干扰作用控制指数评价了印楝素的不同施用浓度和使用次数对柑橘园柑橘全爪螨自然种群控制作用，并建立了控制效果随这些因素变化的回归模型。结果表明，印楝素的使用次数对柑橘全爪螨种群的影响程度强于施用浓度，印楝素单独使用一次不能有效控制柑橘全爪螨种群的数量增长趋势，印楝素3.75 mg/L浓度使用2次或2.50、3.00 mg/L浓度使用3次，可使柑橘全爪螨种群数量得到较为有效的控制。

Control effects of azadirachtin to Panonychus citri natural population in citrus orchard

Citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychidae), is a key pest of citrus in China. By uniform design method, interference index of population control (IIPC) was used to determine the control effect of azadirachtin under different application frequencies and different application concentrations on citrus red mite natural populations in citrus orchard. The model of relationship between the control effect and the factors was set up. The results showed that the application frequency of azadirachtin on citrus red mite population was more important to interference index of population control than the concentrations of azadirachtin. One time treatment of azadirachtin alone was unable to effectively control the number of citrus red mite population. When a.i.3.75 mg/L of azadirachtin was used for more than one time and a.i.2.50 mg/L and a.i.3.00 mg/L used for more than two times in citrus orchards, the increasing trend of citrus red mite population could be controlled effectively.