摘  要  【目的】 研究2代区第1代二化螟Chilo suppressalis为害对水稻产量的影响。【方法】 通过人工接种二化螟黑头卵模拟2代区第1代二化螟为害对水稻产量损失的影响。【结果】 2代区第1代二化螟幼虫危害造成水稻枯鞘、枯心和枯死株，致使单位面积有效穗数减少，产量降低。随着接卵量增加水稻被害株率增加，产量损失率增加，接卵量与产量损失率的关系符合方程y=0.039x﹣2.793。根据害虫经济阈值的定义，推算出1代二化螟卵量防治指标为111块/667 m²，通过分析越冬代性比和雌蛾产卵量数据，提出二化螟成虫防治指标为灯诱累积20.2头或性诱累积8.3头。【结论】 明确了1代二化螟卵量和成虫的防治指标，对二化螟的早期防治有重要指导意义。

Abstract  [Aim]  To determine the loss inflicted on rice crops by the first generation of Chilo suppressalis in two regions. [Methods]  The relationship between the occurrence of the first generation of C. suppressalis and crop loss was studied by artificially inoculating rice plants with C. suppressalis egg-masses. [Results]  First generation larvae in a second-generation area caused withered sheaths, withered hearts and plant death. As a result, the number of effective panicles per unit area of rice was reduced and yield decreased. The loss rate increased with the number of eggs; the correlation between crop loss and the number of egg-masses per 667 m² can be described by the equation: y = 0.039x﹣2.793. According to the definition of an economic threshold, the control index for the first generation of C. suppressalis is 111 egg-masses per 667 m². By analyzing the sex ratio and oviposition of the overwintering generation, we propose that the control index for adults be set at 20.2 for light trapping, or 8.3 adults for sex-pheromone trapping. [Conclusion]  These results provide important information for the early control of C. suppressalis in rice crops.