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[目的]研究影响二点委夜蛾发生和为害程度的重要因素。[方法]分析近几年二点委夜蛾主害代发生期间的降雨等气象因素,探讨影响其发生及为害程度的重要因素。[结果]小麦生长后期田间湿度较高,尤其是一代蛾盛期以及卵孵化期和低龄幼虫期间的降雨,是决定幼虫发生数量的关键因素,如果降雨时期与蛾盛期高度吻合,会使产卵量明显增加,而降雨时期与卵孵化或低龄幼虫期的高度吻合,卵孵化率和幼虫存活率将大幅度提高。但低龄幼虫至4龄期如果降雨过于猛烈,引起田间积水严重且淹水时间过长,则会对幼虫造成淹死情况,使田间为害株率降低。主害代幼虫为害程度还受秸秆腐熟程度的影响,而秸秆腐熟程度则受降雨时间、降雨日数及降雨量的影响,如果降雨从5月开始,6月雨量大或雨日多,秸秆腐熟加快,则田间秸秆堆的结构被改变,压实无缝隙,将影响成虫躲藏、产卵,且土表腐殖质的增多,为二点委夜蛾提供了丰富的食料,将降低对玉米苗的为害率。[结论]阴暗潮湿的环境有利于二点委夜蛾发生为害。
[Objective] The research aimed to study the important factors which affect the occurrence and damage degree of Spodoptera litura. [Method] The paper analyzed the meteorological factors such as rainfall during the occurrence of the main generation of the ladybird in the recent years and discussed the important factors that affect its occurrence and damage. [Result] The higher field humidity in late stage of wheat growth, especially the peak moth and the rainfall during egg hatching and young larvae were the key factors to determine the number of larvae. If the rainfall period is highly consistent with the moth plume, The amount of eggs increased significantly, while the rainfall period coincided with that of egg hatching or young larvae. The egg hatching rate and larval survival rate would be greatly increased. However, if the rainfall of younger larvae to the 4th instar is too violent, causing severe flooding in the field and long flooding time, it will cause drowning of the larvae and reduce the rate of damage to the field. The degree of damage to the main larvae is also affected by the degree of maturity of the straw, while the degree of maturity of the straw is affected by the rainfall time, the number of rainfall days and rainfall. If the rainfall starts from May, , Then the structure of the field straw heap is changed, compaction seamless, will affect the adult hiding, spawning, and soil surface humus increased, for the two members to provide a rich diet food, will reduce the damage rate of corn seedlings . [Conclusion] The dark and humid environment was beneficial to the occurrence of the second instar larvae.