麦圆叶爪螨为害损失及防治指标研究

Study on damage loss and control threshold of Penthaleus major

麦圆叶爪螨对小麦的为害有秋、冬季和春季两个明显时期。秋、冬季为害和春季为害均随着麦圆叶爪螨发生数量的增加,而使小麦产量下降。产量损失率(秋、冬季为害产量损失率y4′,春季为害产量损失率y8)与麦圆叶爪螨发生数量(秋、冬季为x1;春季为x2)均呈极显著的回归关系。其关系式分别为y4′=0.030 0x1-0.882 5,y8=0.016 2x2-0.275 7。拟定350 kg/667m2产量水平下,小麦越冬期和春季麦圆叶爪螨的防治指标分别为33cm单行长小麦上螨口112头和170头。

Penthaleus major Duges made severe damages on wheat during autumn-winter and spring . The wheat yield decreased with the increment of the quantity of Penthaleus major Duges, which showed the two factors had significant correlations as followings： y4′= 0.030 0 x1-0.882 5, y8 = 0.016 2 x2-0.275 7. At the condition of 350 kg/667m^2 of wheat yield, control threshold was proposed as 112/33cm single file in spring and 170/33 cm single file in wheat over-wintering stage.