玉米铁甲虫卵、幼虫空间分布型及其抽样技术初步研究

PRELIMINARY STUDIES ON THE SPATIAL PATTERNS OF EGGS AND LARVAE OF DACTYLISPA SETIFERA (CHAPUIS) AND THE SAMPLING TECHNIQUES

玉米铁甲虫卵、幼虫空间分布型均属负二项分布。卵分布的基本成分为疏松的个体群,个体群大小约为3～4株玉米所占面积。在临界密度m。=2、保证概率90％下,卵量调查的序贯抽样的卵量区间为:T=20N±26.63N^(1/N)最大抽样数为27株;按改进的Iwao模型,序贯抽样的卵量区间为:T’=20N±27.36N^(1/N),最大抽样数为29株。

The spatial patterns of the eggs and larvae of Dactylispa setifera (Chapuis)were found in agreement with the negative binomial distribution in the corn field. The basic component of the eggs was a loose individual clump which size was an area occupied by 3 to 4 plants of corn. ,The sequential sampling of the eggs fitted into the equation as follows, T=2ON±26.63N^(1/2), (90％ of confidence limits, the thr.eshold density of eggs: m_0=20). According to the improved Iwao's m—m Model, the equation became: T'=20N+27.36N^(1/2). And the maximum samples of eggs for the two equations were 27 and 29, respectively.