椰心叶甲幼虫空间分布及其抽样技术研究

本文采用多种聚集度指标对椰子树Cocos nuciferaL．上的椰心叶甲Brontispalongissima（Gestro）幼虫的空间分布型进行了研究，结果表明：椰心叶甲幼虫空间分布为聚集分布；其幼虫虫口密度在不同心叶及心叶不同部位上差异极显著，并且第一片心叶上幼虫虫口密度与整株幼虫数量显著相关，利用公式y=5．70＋1．26x可推算整株椰子树的幼虫虫口密度。分析寄主受害斑与虫口密度的关系表明，寄主受害斑的长（x1）、宽（x2）、长与宽交互作用（x3=X1x2）三个因子与椰心叶甲虫口密度（y）成正相关，模型Y=11．81—2．69x2＋0．10x3可预测全树幼虫虫口密度。

Spatial distribution of Brontispa longissima (Gestro) larvae and its sampling techniques

Aggregation indices were used to determine the spatial distribution patterns of the larva of BrorUispa longissima (Gestro) in this paper. The results showed that they were all assembly distribution.There were extremely significant difference in the larval population densities between different central leaves, as well as different parts of the central leaves. The number of larvae in the first central leaves were significantly correlated with that on the whole tree. So the number of larvae in the whole tree could be calculated with the formula y = 5. 70 +1. 26x. Analysis of relationship between damage spot and population density indicated that the length (x_1) , width (x_2) and length x width (x_3 =x_1x_2) of damage spot all showed positive correlation with population density (y). Using the formula y = 11. 8117 - 2. 6855 x_2+0. 1033 x_3 could project the whole tree's larval population.