大黑和暗黑蛴螬危害花生的防治指标研究

STUDIES ON THE DAMAGES AND CONTROL THRESHOLDS OF HOLOTRICHIA OBLITA FALDERMANN AND H.MOROSA WATERHOUSE TO PEANUT

花生种苗期大黑蛴螬和花生生长期大黑、暗黑蛴螬的虫口密度(X)与减产率(Y)呈明显的直线正相关,其相关式苗期网池接虫为Y=0.7245+0.004X±3.3957(r=0.9520,n=39);同步模拟为Y=0.4452+0.0040X±1.3959(r=0.9661,n=28);接虫示范为Y=0.1360+0.0074X±1.5888(r=0.9800,n=4);生长期接大黑金龟甲卵为Y=1.2927+0.0042X±3.2704(r=0.8993,n=36);接暗黑金龟卵为Y=0.7308+0.0042X±2.1344(r=0.9568,n=32)。研究分析提出花生种苗期防治指标为三龄大黑蛴螬每平方米2头;生长期防治指标为每平方米大黑卵3粒,暗黑卵5粒。

There were significant linear relations between the grub populations(X) of Holotrichia oblita (in seed-seedling stage and growing stage ofpeanut) and H.morosa (in growing stage) and the yield loss rates ofpeanut (Y).The regression equations of a series of experiments,na-mely,grub inoculation in caged basins(1),simutaneous modulation(2),grub inoculation in demonstration plots (3),egg (of H.oblita and H.morosa) inoculation in growing stage (4) & (5),were described res-pectively as follows: Y=0.7245+0.0040X±3.3957(r=0.9520,n=39) (1) Y=0.4452+0.0040X±1.3959(r=0.9661,n=28) (2) Y=0.1360+0.0074X±1.5888(r=0.9800,n=4) (3) Y=1.2927+0.0042X±3.2704(r=0.8993,n=36) (4) Y=0.7308+0.0042X±2.1344(r=0.9568,n=32) (5) The results suggested that the action thresholds were 2 (threeinstar)grubs(H.oblita)per square meter in seed-seedling stage and 3 (H.oblita) or 5 (H.morosa) eggs per square meter in growing stage.