二点委夜蛾越冬规律研究

二点委夜蛾是2005年在河北省夏玉米上新发生的重大害虫,其研究资料仅仅是作为一般昆虫种类进行的记载,无发生规律的相关文献,其中有关该害虫越冬规律研究的报导是空白。作者经过多年系统监测,采用全省普查、定田系统调查、罩网定点定期调查和人工饲养定时观测的方法,澄清了二点委夜蛾的越冬场所、越冬方式、越冬虫态和死亡情况。在河北省,10月上旬末代幼虫在玉米、花生、甘薯和棉花等田间出现,秋收过后则在上述作物的冬闲地越冬;在田间残存的植物干秧子上或下,落叶中或落叶下,以结土茧或老熟幼虫的方式越冬,或进入土壤的浅表层结土茧越冬。越冬前有部分幼虫被寄生或死亡。人工饲养观察结果显示,10月下旬为末代幼虫结茧期,到11月中旬幼虫大多已经结茧越冬。越冬基数调查采用摸查方式,或粗筛筛查虫体。研究结果可为二点委夜蛾的监测与治理提供科学依据。

Study on Overwintering Regularity of Proxenus lepigone

Proxenus lepigone was a new major corn pest in Hebei.It was only recorded as a general of insects,there were no related literatures of occurrence rules.The overwintering place,ways and stage,and death of P.lepigone were clarified by system monitoring for many years using the methods of mass screening in Hebei,artificial feeding and timing observation.The results showed that the final generation larvae emerge in the field of corn,peanut,sweet potato and cotton in the first ten days of October in Hebei.After harvesting in autumn,it overwintered with larvae in earth-cocoon or mature larvae under or in the survival plants and leaves,or with earth-cocooned larvae in shallow soil in winter fallow field of above crops.A part of larvae were parasited or dead before overwintering.It was found that the cocooning period of final generation larvae was in the last ten days of October,most larvae had cocooned to overwinter in middle of November.The overwintering base was investigated with methods of feeling by hand,and screening soil and survival plants with coarse sieve.The results could offer scientific basis for monitoring and control.