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玉米螟是玉米的主要害虫,石家庄地区一年发生三代。近年来随着耕作制度的改革和春玉米种植面积的减少,迫使一代玉米螟集中危害棉花和少量的春玉米,棉麦间作田的棉苗受害更重,一般被害率5—10％,有的高达20％以上。玉米螟危害棉株时,多以2—3龄幼虫从棉株中、下部蛀入茎内,向上或向下蛀食,形成3厘米长的隧道,致使被害株顶端萎蔫或在蛀孔处折茎,阻止了果枝的继续形成。一般幼虫在一株上蛀食一天后就转至另外一株,每头幼虫可危害7—8株棉花。另外,幼虫也蛀食叶柄与蕾、铃,形成叶片下垂枯萎,花蕾脱落或破坏棉纤维,严重影响棉花的产量和品质。防治方法:1.推广棉田内种植玉米诱
Corn borer is the main pest of corn, Shijiazhuang area occurs three generations a year. In recent years, with the reform of farming system and the reduction of planting area of spring corn, the generation of corn borer will be forced to endanger the cotton and a small amount of spring corn. The cotton seedlings between cotton fields and wheat fields will be harmed more, and the damage rate will be 5-10% Up to 20% or more. Corn borer damage to cotton plants, more 2-3 instar larvae from the cotton plant, the lower part of the stem bore into the upward or downward feeding, the formation of 3 cm long tunnel, resulting in the top of the victim wilt or off Stems prevented the fruiting branches from continuing to form. General larvae in a strain on the one day after the transfer to another strain, each larvae can endanger 7-8 cotton. In addition, larvae also eaten petiole and buds, bells, the formation of leaves sagging withered, flower buds fall or destroy the cotton fiber, seriously affecting the yield and quality of cotton. Prevention and treatment methods: 1. Promote corn planting cotton seduction