But the maximum occurrence of H. assulta, H. armigera and S. litura was in the mid-August, the average density was 3.9 and 3.0 per plant, respectively.

• 斜纹夜蛾、烟青虫和棉铃虫幼虫的发生高峰期均在8月中旬，平均每株虫量3.；9头、斜纹夜蛾3