刚竹毒蛾聚集分布原因及密度估计方法

Type of Distribution and Method of Density Estimation for Pantana phyllotachysae

毛竹(Phyllostachys pubescens Marel ex H.de Lehaie)是闽北山区重要的森林资源,南平地区现有毛竹林面积约2.6×10~5hm^2,占全省竹林面积的42％,全国的9.2％。近年来,刚竹毒蛾(Pantana phyllostachysea,Chao)对竹林的危害日益严重,平均每年被害面积达5000hm^2。危害严重的竹林状如火烧,、竹叶被食光,竹节积水,竹干腐烂枯死。

In northern Fujian, the type of distribution of overwintering larvae and egg masses belongs to aggregation distribution, which is resulted from its biological characteristics and environmental heterogeneity. The relationship between site condition and pest density was studied, The results showed that its egg density was affected by the vegetation in the forest. And the density of egg and larvae decreases with the increase of crown density. The percentage of trees infested is positively related to the larvae and/or egg density. The formula is fitted for the expression of relation between pest density and percentage of trees infested. However, attention should be paid to the selection of appropriate high or low limits for the estimation of its population density.