切梢小蠹属昆虫分类鉴定方法

采用形态学和分子生物学相结合的方法,建立一套快速、准确鉴定切梢小蠹的特征系统。利用鞘翅斜面第2沟间部的瘤状颗粒和刻点分布、鞘翅斜面刚毛长短和前胸背板刻点及刚毛分布3种特征,在体视显微镜放大30倍条件下可实现切梢小蠹虫的准确鉴定。通过形态鉴定为同种的小蠹虫在利用28Sr DNA序列片段构建的系统发育树上能首先聚在一起,并且切梢小蠹属昆虫种下、种间和种上的遗传距离分布在3个不重叠的范围内,利用28Sr DNA基因构建切梢小蠹属分子鉴定体系是理想的方法之一。通过系统发育树的聚类分析或遗传距离比较均可实现种类鉴定。

Classification of Tomicus Species

Both morphological characters and a portion of of 28S rDNA sequences were used to identifying Tomicus species.The specimens were classed into groups with the following characters:1) granules or punctures on interstria 2 on the declivity of the elytra.2) length of the elytral interstrial hairs and hairs arising from punctures.3)arrangement of pronotal punctures and hairs.These characters could be clearly examined under a binocular microscope at 30×magnification and they were applicable and valuable for the forest entomologists to identify Tomicus species.The phylogenetic tree established with difference in 28S rDNA sequence of D2 region revealed that the specimens of each group identified by morphological characters were also grouped together.The genetic distances of intra-species,inter-species and inter-genus were not overlapped.Genetic divergence of 28S rDNA was also useful for identifying Tomicus species.