粟穗螟幼虫一生取食量与受害高粱穗的生育阶段呈反相关系,主要为害期为高粱灌浆至蜡熟期。每穗虫量与产量损失率呈幂函数回归关系,室内饲养和田间接虫测定的公共方程为y=0.977x~(0.88),经济阈值按曹赤阳(1986)修正Chiang.H.C.(1979)模式计算。在亩产量200～250公斤下,防治指标以150～200头/百穗为宜。 The lifetime feeding amount of M. frugiperda larvae was inversely related to the growth stage of sorghum spike, and the main damage stage was the sorghum grain filling to wax maturity. The result of power function regression showed that there was a positive correlation between the number of earworms per ear and the rate of yield loss. The public equation for indoor rearing and fieldworm measurement was y = 0.977x ~ (0.88). The economic threshold was calculated according to the revised model of Cao et al. (1986) Chiang.H.C. (1979). In the mu yield of 200 ~ 250 kg, the control index to 150 ~ 200 head / hundred spike appropriate.