光肩星天牛在杨树上产卵部位的选择

Oviposition Site Selection on Poplar Trees by Anoplophora glabripennis Motsch. (COLEOPTERA:CERAMBYCIDAE)

对光肩星天牛危害杨树的调查表明，光肩星天牛产卵处的高度与杨树胸径呈正线性相关．以往认为光肩星天牛喜在树干分枝处的观点只适用于胸径大于１５ｃｍ的情况，而在胸径小于１５ｃｍ的情况下，光肩星天牛主要产在主干基部或中部无分枝处．进一步调查的数据表明，光肩星天牛产卵时对树干直径、树皮厚度有严格的选择．对鲁伊莎杨测量分析的结果表明，树干直径与树皮厚度间存在着密切的正线性相关关系，这意味着光肩星天牛只要对两因子之一进行选择，另一因子也就同时确定了．据林间观察和分析。

The field survey on poplar forests damaged by Anoplophora glabripennis shows that there is a positive linear correlation between the height of oviposition site and the breast height diameter.That A.glabripennis prefered laying its eggs on the branch site of the stem as reported in the past is only appliable to the situation when the host breast height diameter is greater than 15cm.However,when the host breast height diameter is less than 15cm,A.glabripennis mainly lays its eggs on the middle and lower parts of the trunk,where there is no branch. Data of further survey indicates that there is strict oviposition selection of the stem diameter and the bark thickness in A.glabripennis. The results of measurements and analyses on Populus cv.‘Lusia Avenzo’show that there is close positive linear correlation between the stem diameter and the bark thickness. It implys that if A.glabripennis selects one of the two factors, the other one is chosen at the same time. Based on the field observation and analysis, the bark thickness seems more important for oviposition site.