玉米螟为害棉花虽早有记载,但作为棉花现蕾期的主要害虫,则是近年来耕作制度和作物布局发生重大变化的结果。 棉田玉米螟发生的新特点 玉米螟在本地一年三代,过去以第三代幼虫为害棉铃为主,重者30％以上,一般1％以下,第一、二代幼虫为害茎叶仅零星发生,因而并不视为主要棉花害虫。但据1984、1985两年 Although the damage caused by corn borer cotton has long been documented, the major pest in the cotton budding stage is the result of major changes in the farming system and crop layout in recent years. Corn borer occurred in the new characteristics of the corn borer in the local year three generations, in the past the third generation of larvae for cotton boll-based, more than 30%, generally less than 1%, the first and second larvae damage stems and leaves only sporadic occurrence, It is not considered a major cotton pest. But according to 1984,1985 two years