1999年玉米蓟马在嵩县乃至豫西地区偏重发生,玉米苗严重受害,全县发生面积0.67万ｈｍ2,占玉米播种面积的50%,较历史上发生较重的1992年增加了20倍。其中严重受害面积0.2万ｈｍ2,受害田被害株率一般为20%～30%,较1992年提高15～20个百分点,严重的达50%以上。受害株一般为叶... Maize thrips occurred in Songxian and even in western Henan Province in 1999, with serious maize seedlings. The county had an area of ​​66700 hm2, accounting for 50% of the maize acreage, an increase of 20 times over that of 1992. Among them, the serious affected area is 0.2 million hm2. The victimized farmland rate is generally 20% -30%, which is 15-20% higher than that in 1992 and seriously over 50%. Damaged plants are generally leaves ...