松褐天牛在马尾松树干上的分布规律

Distribution of Monochamus alternatus on the Trunks of Pinus massoniana

作为松材线虫病(Bursaphelenchus xylophilus)的最重要传播媒介,松褐天牛已成为控制松材线虫病的重点。明确松褐天牛各虫态在不同地区寄主树干上的分布,对因地适宜地释放天敌昆虫有着重要意义。为此,本研究通过解剖受害马尾松,结合林间调查,系统地研究了松褐天牛产卵刻槽、幼虫和蛹在马尾松树干上的分布规律。结果表明:松褐天牛产卵刻槽主要分布在树干的2.5 6.5 m范围内,刻槽数量与树干高度和胸径显著相关;松褐天牛幼虫数量与树干胸径关系不显著;多数蛹室位于侵入孔正上方,少数蛹室位于侵入孔下方,两种蛹室数量差异显著;两种蛹室与侵入孔中心的平均距离分别为3.93 cm和4.39 cm,两者之间差异不显著;并建立了松褐天牛幼虫在马尾松树干上的垂直分布模式图。本研究表明了松褐天牛种群密度与寄主树木大小的关系,为释放天敌进行生物防治提供了基础。

The biological control of pine sawyer, Monochamus alternatus, the most important vector of pine wood nematode disease, Bursaphelenchus xylophilus, is an important method for the effective management of pine wood nematode disease. Understanding the distribution of the different staged M. alternatus on the host trunk is very im- portant for releasing natural enemy insects in the particular conditions. The distributions of oviposition cut marks, larvae and pupae of pine sawyer on the trunk of Pinus massoniana were systematically investigated. The results showed that the oviposition cut marks were mainly distributed in 2.5 ~ 6.5 m of the host trunk. The amount of ovi- position cut marks exhibited a significant positive linear relationship with the diameter of host trees, bat a parabolic relationship with the host height. By contrast, no significant regression relationship was found between the amount of larvae and host diameter. The amount of pupa cells located above the entrance holes was significantly higher than those under the entrance holes. The average distances from the two types of pupa ceils to the larvae entrance holes were 3.93 cm and 4.39 cm, respectively ; there was no significant difference between them. Furthermore, a larvae vertical distribution model illustration in the trunk of P. massoniana was set up to exhibits the patterns. These find-ings suggested that the population density of pine sawyer was related with the host tree size. This might provide a fundamental data of the amount of natural enemies that being released in biological control.