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观察了斜纹夜蛾第4代和第5代自然种群各虫态存活率、性比、产卵量和种群趋势指数,应用控制指数分析法分析天敌等因子对斜纹夜蛾自然种群的控制作用结果表明,第4代和第5代斜纹夜蛾自然种群卵孵化率分别为88.34％和89.33％,蛹存活率分别为57.74％和61.48％,幼虫期存活率分别为0.78％和0.63％,成虫性比接近1:1,雌成虫产卵量平均1723粒和1477粒,种群趋势指数分别为3.145和2.31。在各类作用因子中“蜘蛛”对斜纹夜蛾种群数量控制作用最大,控制指数分别高达12.83和9.06,其次是“疾病及自然死亡”等因子。
The survival rate, sex ratio, fecundity and population trend index of natural populations of fourth and fifth instars of Spodoptera litura were observed, and the control effect of natural enemies and other factors on the natural populations of Spodoptera litura was analyzed by using control index analysis The results showed that the egg hatching rates of the 4th and 5th generation Spodoptera litura were 88.34% and 89.33% respectively, the survival rates of pupae were 57.74% and 61.48%, respectively. The survival rates of larvae were 0.78% and 0.63% Nearly 1: 1, the fecundity of female adults was 1723 and 1477, respectively. The population trend indices were 3.145 and 2.31 respectively. In all kinds of action factors, “spider” has the most control effect on the population number of Spodoptera litura, the control index is as high as 12.83 and 9.06 respectively, followed by “disease and natural death” and other factors.