沿海蝗区东亚飞蝗(Locusta migratoria manilensis)产卵场所选择的Logistic回归模型

以沿海蝗区南大港水库为研究区域，通过2002和2003两年野外450，50m规则栅格取样获取东亚飞蝗卵块、植物种类及其密度、土壤特性如含盐量、5cm含水量、pH、有机质及地形（阴坡和阳坡）等数据，采用多元Logistic回归模型，运用SAS软件筛选出与飞蝗产卵场所选择密切相关的变量，建立用于预测飞蝗产卵场所选择的Logistic回归模型。结果表明用植株密度（veg—d）和土壤含水量（water）所组建的模型能较好地预测飞蝗产卵选择,log（P（Y=1）/1-P（Y=1））=21．63-76.23/water-5．43log（water）-0．86（veg_d）。利用拟合优度（Goodness of fit）、预测准确性（Predictive accuracy）及模型x^2统计（Model chi—square statistic）等指标对模型进行评价的结果表明，所组建的用于预测飞蝗产卵场所选择的Logistic回归模型是可靠的，且能较好地预测事件是否发生。研究结果为区域蝗灾早期预警提供了科学依据和方法，对今后预测飞蝗产卵地点选择及防治决策有较高的实用性和应用价值。

Prediction on oviposition site selection Locusta migratoria manilensis by logistic model in coastal areas

The multi-logistic regression method was used to establish a regression model for predicting oviposition site selection in the Locusta migratoria manilensis in Nandagang farm,a coastal area Hebei province.Eight potential factors are observed including vegetation species and densities,soil properties(water content at 5 cm depth,salinity,pH and organic matter)and microrelief properties(south slope and north slope)in coastal areas.Data of locust eggpods,vegetation,soil and microrelief were collected from two spatial scales in 2002 and 2003:450m intervals throughout the study area,and 50m grids for the possible egg-laying areas where locust plague occured or vegetation was sparse.The obtained regression model includs only vegetation density(veg_d)and soil water content at 5 cm(water),logP(Y=1)/1-P(Y=1)]=21.63-76.23/water-5.43log(water)-0.86(veg_d).Where P(Y=1)is the probablity of a site selected by Locusta migratoria manilensis.After evaluated by methods of Goodness of Fit,Predictive Accuracy and Model Chi-square Statistic,the established regression model is proved to be reliable and can predict eggpods occurrence well.This model can be used for locust plague prediction and early decision-making of its control.