河北省二点委夜蛾的发生规律研究

二点委夜蛾是2005年在河北省新发现的玉米害虫,近年来在我国夏玉米种植区发生日趋严重。由于该虫发现时间短,因此可以借鉴的资料有限。2005年以来,作者对河北省二点委夜蛾的发生规律进行了持续研究,目前澄清了年发生世代和幼虫为害习性。在河北省,二点委夜蛾全年发生4代：越冬代成虫4月中旬～5月底,1代成虫6月～7月上旬,2代成虫7月上中旬～8月上中旬,3代成虫8月下旬～10月中旬;幼虫主害期为夏玉米苗期（6月～7月上旬）,7月下旬以后对玉米损害不大。幼虫对玉米苗的为害方式主要是咬食茎基部和根部,破坏输导组织,从而导致植株萎蔫甚至死亡。幼虫对高温敏感,田间湿度大时有利于该虫的发生。二点委夜蛾幼虫的天敌是蚂蚁。

Study on Occurrence Regularity of Athetic lepigone in Hebei Province

Athetic lepigone was a newly discovered pest of corn in Hebei.In recent years its occurrence became more and more serious in summer corn growing areas.Because of the short discovery time of the pest,the references were limited.The occurrence regularity of this pest in Hebei had been studied since 2005,and the generations per year and the damage of larvae were clarified.A.lepigone occurred 4 generations a year,the overwintering generation,the first generation,the second generation and the third generation occurred from the middle ten days of April to the end of May,from June to the first ten days of July,from the first and middle ten days of July to the first and middle ten days of August,from the last ten days of August to the middle ten days of October.The damage stage of larvae was at the seedling stage of summer corn（from June to the first ten days of July）,and its damage was not serious after the last ten days of July.The damage of larvae was to bite stem base and root of corn seedling to damage the conducting tissue,then led to wilted and even death.The larvae were sensitive to high temperature,and high humidity in field was beneficial to the occurrence of the pest.The natural enemy of this pest was ant.