棉铃虫卵粒在棉株上的空间分布型与抽样技术

The spatial distribution pattern and sampling technique of egg of cotton bollworm on the cotton fields

通过１９９６年在第三、四代棉铃虫盛发期对２７块棉田的２７００棉株上的卵量随机抽样调查，经Ｉｗａｏ聚集指数测定，ｍ／ｍ＞１；Ｔａｙｌｏｒ幂法测定，ａ＝２１４６２＞０，ｂ＝１３７１７＞１；Ｉｗａｏｍ—ｍ回归分析，ａ＝－００４０１≌０，ｂ＝２５４４０＞１。结果表明，棉铃虫卵粒呈聚集分布。又经Ｉｗａｏ法计算理论抽样数量获如下模式：ｔ＝１９６≌２，Ｄ＝０１，ｎ＝（３８３９６／ｘ）＋６１７６；ｔ＝１９６≌２，Ｄ＝０２，ｎ＝（９５９９／ｘ）＋１５４４；ｔ＝１９６≌２，Ｄ＝０３，ｎ＝（４２７／ｘ）＋６８６。

The spatial distribution pattern and the sampling methods of egg of cotton bollworm, Helicoverpa armigera(Hübnen), were systematically studied by investigating the eggs of 3rd and 4th generations at Xiaoshan cotton area of Zhejiang Province in 1996 Three theoretical models of analysis were developed by accepting the methods of Iwao's index of aggregate, Taylor's power law and Iwao's —m regression The results showed that the spatial distribution pattern of egg of cotton bollworm belonged to aggregate distribution in typical cotton fields The numbers of sampling varied with the egg's density and expected accuracy of egg investigation in cotton fields