斑膜合垫盲蝽若虫在国槐上的空间分布型及抽样技术

斑膜合垫盲蝽Orthotylus(O.)sophorae Josifov是近年来临夏地区国槐Sophora japonica Linnaeus上严重发生的害虫之一。应用6种分布型指数法分析判定了斑膜合垫盲蝽若虫在国槐上的空间分布型,利用Taylor幂法则和Iwao回归方程分析聚集原因,结果表明,斑膜合垫盲蝽若虫在国槐上呈聚集分布,公共k c值为0.6169,且符合负二项分布;其种群聚集是由某些环境作用引起的。在此基础上,采用Iwao的方法确定了斑膜合垫盲蝽若虫的田间最适抽样数和序贯抽样表;并根据Gerrard的零频率模型建立了估计该种群平均密度的零频率公式:x=1.7457(-lnP0)1.1119。

Spatial distribution pattern and sampling technique for Orthotylus (O.) sophorae nymphs on Sophora japonica

Orthotylus sophorae has become a serious pest for Sophora japonica in Linxia Prefecture of Gansu Province in recent years. The spatial distribution pattern of O. sophorae nymphs in S. japonica garden was determined by six spatial distribution pattern indices, and the assembling reasons were analyzed using Taylor's regression model (1961) and lwao's regression equation (1971). The results indicated that the aggregated distribution of O. sophorae nymphs in the field fits the negative binomial series (k_c=0.6169). The reason for the aggregation may be due to some environmental factors. On the basis of the distribution pattern, the optimal sampling number and sequential sampling table were calculated using lwao's method. The zero frequency model for the mean density estimation of O. sophorae nymphs was established on the basis of Gerrard's method (1970) as follows:x=1.7457(-lnP_o)^1.1119.