松墨天牛取食行为及其与寄主挥发物的关系

研究了松墨天牛Monochamus alternatus对于寄主植物马尾松Pinus massoniana不同部位的取食选择性,并对相应部位的挥发物进行了成分分析。室内取食试验结果显示,松墨天牛对不同年龄的寄主植物枝条有显著的取食选择性,取食量大小顺序为:1年生>3年生>2年生枝条;野外取食调查结果显示,松墨天牛对寄主植物树冠的不同层次和不同方向枝条也存在显著的取食选择性,取食量大小分别为:中层>上层>下层,南向>北向。气相色谱-质谱联用仪(GC-MS)分析结果显示,不同部位枝条挥发物成分差异很大,其中不同枝条挥发物中的α-蒎烯含量为:1年生>3年生>2年生枝条,上层>中层>下层,不同方向枝条α-蒎烯含量为:南向>北向。对比分析发现,松墨天牛喜欢取食的枝条往往α-蒎烯在挥发物中的含量较高,也含有更多的微量成分。这些因素很有可能对松墨天牛取食行为扮演着积极促进的角色。图3表2参10

Feeding behavior of Monochamus alternatus and its relationship with the host volatiles

Feeding preferences，using laboratory feeding assays，of Monochamus alternatus adults on twigs of different ages，crown levels，and orientations for Pinus massoniana were studied by identifying and comparing their volatile profiles with a gas chromatography mass spectrometry （GC-MS） analysis. Results of the feeding assays of P. massoniana twigs demonstrated that M. alternatus fed preferentially on young tissue （one- ＞three-＞two-year-old tissue）. Similar feeding assays showed that adult M. alternatus fed preferentially on twigs at different crown levels （mid level＞upper level＞lower level） and orientation （south＞north）of the tree. The GC-MS analysis showed that α-pinene content  for different twigs of P. massoniana were different: one-＞three-＞two-year-old tissue，upper＞middle＞lower，and α-pinene content at the sides of the host crown being: south＞north. The comparison showed that M. alternatus adults preferred twigs with high α-pinene content.  ［Ch，3 fig. 2 tab. 10 ref.］