晋中盆地麦蚜发生为害程度及原因分析

晋中盆地麦蚜发生为害高峰常出现于小麦孕穗到灌浆期,大发生年发生高峰可提前至拔节期。从1998～2003年连续6年的系统观察调查得出,遇暖冬及早春温暖干旱气候,麦蚜呈现早发生或大发生;如遇冬春低温多雨,尤且是1～2月份极端温度低于-20℃,时间长达15d时,对麦蚜发生形成明显抑制。另外,蚜虫发生程度与天敌数量关系密切,小麦播种面积与蚜虫发生总量呈正相关关系。

Damage Extent and Cause of Wheat Aphid in Jinzhong Basin

The infection peak of wheat aphid usually outbreaks at stage from ear bearing to filling and in the serious year the outbreak could be put off till stem elongation stage.The results of 1998～2003 six-year survey showes that when it is warm winter or early spring drought,wheat aphid would outbreak earlier or more seriously;When winter/spring is low temperature or rainy,especially extraordinary low temperature of -20℃ in January or Feburary as long as 15 days,it obvious inhabit to the outbreak.Besides,the infection degree showed close relationship with nature enemy population size,and wheat cultivation area and outbreak total sum of aphid showed positive corelationship.