几种植物次生物质对褐稻虱种群的控制作用模拟

为探讨褐稻虱Nilaparvata lugens (Stål)种群生态控制的作用机理，应用状态空间方程和作用因子添加分析法，研究植物次生物质不同组合对褐稻虱种群的控制作用；本研究以薇甘菊Mikania micrantha乙醇提取物、 飞机草Eupatorium odoratum乙醇提取物与现代苦楝Melia azedarach油的不同组合，作用于褐稻虱种群；根据不同虫期的调查数据，拟合出控制矩阵中各分块矩阵的元素值，并对褐稻虱种群的控制作用进行模拟。结果表明：单独施用薇甘菊乙醇提取物（1 g DW/100 mL）、飞机草乙醇提取物（1 g DW/100 mL）、 现代苦楝油（200倍）各1次， 能显著降低褐稻虱种群数量， 然而种群趋势指数I（population trend index）仍在1.00以上，即下代褐稻虱种群仍呈增长趋势，联合添加其中2种或3种能持续控制褐稻虱下代种群的增长。同时，植物次生物质对褐稻虱种群的控制作用主要表现在对成虫产卵的忌避作用，尤其是在本田种群建立的初期，由于其显著的忌避作用, 降低田间卵量，使其种群数量明显降低，可有效地控制其为害。

Simulation of control effectiveness of several secondary metabolites against populations of the brown planthopper,Nilaparvata lugens(Homoptera:Delphacidae)

To research the effect mechanism on ecological control of population of the brown planthopper (BPH), Nilaparvata lugens (Stål), the control effect of secondary metabolities against BPH was simulated and evaluated using state space equation and factor-adding analysis method. The different combining of alcohol extracts from Mikania micrantha, Eupatorium odoratum and Melia azedarach employed BPH population, and constructed the control model of Nilaparvata lugens population system. Based on the data from different stages, the values of systematic matrix were fitted, and the control effect of secondary metabolities against BPH was simulated. The results showed that the secondary metabolites of Mikania micrantha, Eupatorium odoratum, Melia azedarach applied alone, could drastically decrease the population quantity of BPH, yet the population trend index (I) was still above 1.00, which could not control BPH population to a sustainable decrease. Either two or three kinds of secondary metabolites simultaneously could control the increase of BPH population effectively. Meanwhile, the control mechanism of secondary metabolites on BPH population was its deterrent effect, especially in the initial stages of population development. The egg number of BPH was reduced significantly due to the strong deterrent effect on adults of BPH. As a result, the population number and the harm of BPH population were reduced significantly.