小麦中后期草地贪夜蛾为害特征观察

Observation on the damage characteristics of Spodoptera frugiperda to wheat in middle and late stages

自草地贪夜蛾入侵我国以来,多地出现其幼虫为害麦苗的报道,但其对小麦中后期的为害特征未有明确的描述。为明确草地贪夜蛾幼虫期与黄淮海麦区小麦生育期吻合时能否造成危害,本文通过在河南新乡、北京延庆进行田间笼罩和网室接虫试验,对草地贪夜蛾在小麦中后期的为害特征进行了系统观测。结果表明,4月-6月草地贪夜蛾可以为害小麦;罩网情况下草地贪夜蛾可以取食小麦叶片、叶鞘,钻蛀小穗,造成蛀孔,还可以啃食小麦籽粒。在平均百株虫量为6头的网室内,平均被害穗率为11.0%。被害穗剥检发现,蛀孔率平均为17.80%,最高可达35.48%。研究结果为麦田草地贪夜蛾的预测预报和有效防控提供了参考。但本结果仅为笼罩条件下的数据,在田间自然状态下草地贪夜蛾幼虫对中后期小麦的为害情况有待进一步研究。

Since the invasion of the fall armyworm(Spodoptera frugiperda)(FAW)to China,the damage of its larvae to wheat seedling were found in some provinces,but no reports on the damage characteristics of FAW to wheat at middle or late developmental stages.To find out whether the FAW larvae occur at the heading stage could also cause damage to wheat,the experiments were carried out in net cages by artificial infection with laboratory reared FAW larvae in Xinxiang,Henan and Beijing(Yanqing).The results showed that FAW larvae could cause damages to wheat from April to June.FAW larvae could eat wheat leaves,leaf sheath,bore spikelets and make small holes,and sometimes could eat wheat grains.The damaged head was 11.0%in average in the two cages with an average population of six larvae per 100 tillers.The average rate of bored seed was 17.80%,and the highest reached to 35.48%.The results provide basic data for forecasting and integrated control of FAW in wheat fields.However,because the experiments were conducted in net cages,the real damage need to be further verified in open fields.