松墨天牛幼虫在马尾松上的分布规律研究

Study on Distribution of Monochamus alternatus larvae on Pinus massoniana

对松墨天牛（Monochamus alternatus）蛀入孔、蛹室和羽化孔在马尾松树上的分布规律进行了调查研究，结果表明：在马尾松树上的松墨天牛蛀入、孔、蛹室和羽化孔数量随着树体高度的增加呈“钟形”分布，主要集中在寄主的中部，其中2～5in高树干上的蛀入孔数量占总蛀入孔的64．88％，2～5m高树干上的蛹室数量占总蛹室的62．44％，3～6m的羽化孔占总羽化孔的63．47％；松墨天牛的蛀入孔、蛹室和羽化孔在树枝上的分布数量显著高于树干上的分布，说明树枝是幼虫的主要分布部位，同时也是松墨天牛越冬的重要场所；蛀入孔、蛹室和羽化孔的数量与马尾松树胸径没有明显相关性，而且其在马尾松树南北两侧的分布差异也不显著。

Investigations were conducted on distribution of entrance holes, ovipositon scars and exit holes ofMonochamus alternatus in the trunk of Pinus massoniana. The result showed that the number of entrance holes, oviposition scars and exit holes had a ＂bell shaped＂ curve as the increase of tree height, concentrated in the middle of the trunk. The amount of entrance holes and oviposition scars in the tnmk at 2-5 m above ground took 64.88% and 62.44% of the totals, the amount of exit holes in the trunk at 3-6 m above ground occupied 63.47% of the total. It had more entrance holes, ovipositon scars and exit holes at branches than in the trunk, indicating that larvae mainly distributed, overwintered and damaged the branches. Amount of entrance holes, oviposition scars and exit holes had no evident relation with DBH of the damaged tree, and there was no significant difference of their distributions in the south or north par.