稻瘿蚊为害(标葱)的空间分布型及其与有效穗关系的研究

A research on the relations between the spatial distribution forms of damage caused (outonion) by Orseolia oryzae (Wood-Mason) and the effective spikes

稻瘿蚊为害的空间分布型属聚集分布，田间估计稻瘿蚊为害的最佳取样方法为棋盘法和平行线法，当每丛受害超过1苗时，抽样数量可稳定在151丛以下。标葱率和有效穗相关性测定表明：当标葱率在20％以下时，为害程度与有效穗的多少无显著相关；当标葱率大于20％时，标葱率与有效穗呈显著负相关，每受害加重5％，有效穗将减少0．37个／丛。

The Spatial distribution forms of damage causece by Orscolia oryzae (Wood-Mason) belongto the ones of gathering. The best sampling methods in paddy fields to evaluate the damage shouldbe tbe ones of chessboard and parallel lines. When more than one single spike is damaged in eachrice clump, thc number of crump sampling can be controlled under 151. The tests related to theeffective spikes and the rates of out-onion demonstrate that when the rates of out-onion is under20%, there are no remarkable signs between the degree of damage and the effective spikes. However,when the rates of outonion is over 20%, there will be a striking negative effect between the two:When the degree of damage increases 5%, the effective spikes will decrease 0．37 for each clump.