褐稻虱是连晚中后期的主要虫害。一九六九年以来,几乎每年都有1—2个世代严重发生,防治不当,往往造成不同程度的损失,甚至出现毁杆倒伏,严重减产。为了明确褐稻虱不同虫量对水稻各个生育阶段的为害损失率,了解水稻不同生育期损失率的构成,为制订防治指标提供依据,一九七九年我们进行了笼罩养虫和大田接虫试验,现将试验方法和结果简述如下: 一、连晚不同生育期的为害损失率 (一)笼罩第五代褐稻虱为害损失率 1.试验方 Brown planthopper is the main pest even late late. Since 1996, 1-2 generations have taken place every year almost every year. Improper prevention and control have often resulted in varying degrees of losses and even the destruction of lodging rods and serious cuts in output. In order to clarify the damage loss rates of different rice insect pests to different growth stages of rice and to understand the composition of loss rate in different growth stages of rice and to provide evidence for the establishment of control indexes, Test, now the test methods and results are summarized as follows: First, even late at different stages of the damage loss rate (A) covering the fifth generation brown planthopper damage loss rate 1. Experimental side