湖南双季晚稻不同栽培方式对稻飞虱及其天敌的影响

Effects of cultivation methods of late rice on planthoppers and their natural enemies in Hunan Province

2010-2012年，通过盆拍法结合吸虫机采样法调查了湖南双季晚稻不同栽培方式（抛秧、移栽和直播）下稻飞虱及其天敌的发生情况。结果表明：3种不同栽培方式下稻丛分蘖数差异显著，移栽田分蘖数最多，最高分蘖数为1008株/m2，而直播田分蘖数最少，最低仅为259株/m2。栽培方式对稻飞虱若虫孵化率无显著影响，各次调查孵化率均在65％～75％之间。稻飞虱卵的寄生率与分蘖数两者之间呈现负相关关系，直播栽培方式有利于稻飞虱卵寄生性天敌的控害作用。直播栽培方式下褐飞虱和白背飞虱种群密度均小于抛秧田和移栽田，4代和5代褐飞虱田间数量均与分蘖数和有效积温呈正相关关系，而4代和5代白背飞虱种群数量与分蘖数和有效积温无显著相关关系。3年调查共捕获稻飞虱天敌35种，抛秧和移栽栽培方式下系统调查田多样性指数和丰富度指数有高于直播栽培的趋势。

The dynamics of brown planthopper （BPH）,Nilaparvata lugens Stl,white-backed planthopper （WBPH）, Sogatella furcifera Horváth and their natural enemies were investigated in the second cropping season rice through broad-casted seedling （BS）,hand transplanting （HP）and direct seeding （DS）in Hunan Province by suction trap and pot from 2010 to 2012.The results showed that the tiller number differed significantly among the three cultivation methods,with the highest tiller number of 1 008 plants per m2 in hand transplanting paddy field and the lowest of 259 plants per m2 in direct seeding paddy.The cultivation methods had no significant effect on rice planthopper eggs hatching rate which var-ied from 65% to 75%.There was a negative association between planthopper egg parasitic rate and tiller number,which was higher in direct seeding paddy field than others.Both the populations of the 4th and 5th generation BPH were corre-lated positively with tiller number and accumulative temperature,but no significant relationship in WBPH.Moreover, the BPH and WBPH population densities in direct seeding paddy were less than those in broadcasted seedling and hand planting paddy field.Thirty-five natural enemies were recorded during the investigation and there was a tendency toward the higher values of Shannon-Wiener index and Margalef index in broadcasted seedling and hand planting fields than those in direct seeding paddy field.