花生蛴螬损失率的测定与经济阈值的研究

花生受蛴螬为害已成为花生生产上的严重减产因素。暗黑鳃金龟(Holot-richia morosa Waterhouse)在黄淮海地区是优势种之一。一年一代,主要以老熟幼虫过冬。幼虫(蛴螬)嗜食花生荚果。花生亩产与每平方米的蛴螬数量呈负相关,其回归方程为 y=441.38-6.32x(r=0.977~(**)),损失率为1.43%。通过研究认为,花生蛴螬为害花生的经济允许受害水平以2～3%为宜。每亩用50%辛硫磷乳利0.5斤撒毒土防治一次蛴螬时,其经济阈值为每平方米有蛴螬2.58头;如以同样剂量的药液浇毒水时,其经济阈值为每平方米有蛴螬3.65头。

STUDIES ON ECONOMIC THRESHOLD AND LOSSES CAUSED BY THE PEANUT WHITE GRUB,HOLOTRICHIA MOROSA WATERHOUSE

The black chafer Holotrichia morosa Waterhouse is a dominant species among the peanut white grubs complex in the Yellow River and Huai River Basins.It has one generation each year and the winter is passed as high instar larvae and a few adults.This white grub has a food preference for peanuts,the second and third instar larvae being more injurious.Experiments on its damage loss relations showed that losses in peanuts yield are closely correlated to the number of grubs per square meter.The regression equation is:y=441.38-6.32x (r=-0.977^**).It is considered that the economic injury level of the peanut white grub should be kept between 2% and 3%.