玉米螟不但危害玉米,而且还危害棉花,是上海地区玉米和棉花上的主要害虫,受害严重的田块,产量损失均可达二成以上。玉米螟幼虫有钻蛀为害的习性,药剂防治效果一般只达70％左右,上海郊区还有一定数量青饲料玉米田不能进行化学防治,第二代的虫口基数较高,因此采用生物防治等方法压低虫口基数,减少玉米螟对棉花的为害就显得更为重要。 Corn borer not only endangers corn, but also endangers cotton. It is the main pest on corn and cotton in Shanghai. The severely damaged plots have a yield loss of more than 20%. Corn borer larvae have boring damage habits, the general effect of pesticides control only about 70%, there is a certain amount of Shanghai suburbs of green fodder corn field can not be chemical control, the second generation of high population base, so the use of biological control methods such as depression Insect population base, reducing the damage caused by corn borer cotton is even more important.