南美斑潜蝇危害洋葱的产量损失测定和防治指标初步研究

Research for Mensuration of Damaged Yields Losing and Controlling in Onion by Liriomyza huidorbensis

南美斑潜蝇 [Liriomyzahuidobrensis(Blanchard) ,Lh]是冬春洋葱上的主要害虫之一。为将Lh控制在经济危害水平 (EIL)之下 ,采用 1% 70 5 1杀虫素 2 0 0 0倍液 ,在洋葱上Lh初发阶段 ,施药 1,3 ,5次 ,人为造成洋葱上Lh的虫害梯度。应用试验结果 ,建立Lh幼虫量与产量损失的回归方程 :Y =10 3 0 398- 0 415 6x ,r =- 0 970 6 ,Lh幼虫虫口量与产量呈负相关。根据单叶虫量与单株产量相关性的数学模型 :Y =0 40 0 9- 0 0 80 9x ,进行防治指标研究 ,当 y =0时 ,x =4 95 5 5 ,即平均每叶有幼虫

Liriomyza huidobensis is one of main pest in winter spring onion In order to control the damaged level of Liriomyza huidobensis below economy injure level (EIL), adopted 1% 7051 2000× to control it, and the applied times took turn 0,1,3,and 5 Formed the damaged gradient under artificial condition Applied the results of experiment, the mathematics model of larvae numbers and the yield losing is: Y = 103 039 8 -0 415 6 x , r =-0 997 06 ** The relation of the larvae numbers and yield losing is negative relativity According to the relativity of larvae of each leaf and the yield of each, the mathematics model is: Y =0 546 9-0 009 4 x , the controlling index is: Y =0, x =4 955 5, when there are 5 larvae in a leaf, then control immediately