松褐天牛幼虫二维空间格局研究

Study on the Two-dimensional Spatial Pattern of Monochamus alternatus Larvae

【目的】研究松褐天牛(Monochamus alternatus)幼虫二维空间分布格局,为松褐天牛防治提供科学依据。【方法】对不同生境疫点小班内枯死马尾松树上松褐天牛幼虫数量进行了系统调查,应用4种聚集度指标法探析了不同胸径、高度树体中和不同海拔、坡向生境中松褐天牛幼虫空间分布型。【结果】(1)胸径越大、树体越高,聚集的松褐天牛幼虫虫口数量越多。(2)不同胸径和高度的枯死松树中,松褐天牛均趋向于聚集分布,聚集区域随胸径和树体高度的增加呈上移趋势。(3)5 cm以下伐桩中未见松褐天牛幼虫虫体。(4)不同海拔高度枯死松树树体中松褐天牛虫口密度无显著差异,但不同坡向中枯死松树树体中松褐天牛数量呈现变化趋势,南坡>西坡>西南坡>东南坡>东坡>西北坡>东北坡>北坡,不同海拔和坡向中松褐天牛幼虫均呈现聚集分布。【结论】松褐天牛幼虫在枯死松树上的二维空间分布格局主要受到树体胸径、高度的影响。对于松褐天牛的防治工作而言,应根据这些影响因素采取相应的策略,重点关注胸径较大、树体较高以及位于有利坡向的枯死松树,以提高防治效果。

【Objective】It is to study the two-dimensional spatial distribution pattern of Monochamus alternatus larvae,so as to provide a scientific basis for the prevention and treatment of Monochamus alternatus.【Method】The number of larvae on dead pine trees in different habitats was investigated systematically.The spatial distribution patterns of larva in different diameter at breast height(DBH),height,altitude and slope direction habitats were studied by using four kinds of aggregation index method.【Result】(1)The larger the DBH and the taller the tree height,the more the number of Monochamus alternatus larvae gathered.(2)In dead pines with different DBH and height,Monochamus alternatus larvae tended to gather,and the aggregation area moved upward with the increase of DBH and tree height.(3)No Monochamus alternatus larvae were found in the posts below 5 cm.(4)There was no significant difference in population density of Monochamus alternatus larvae in dead pine trees at different altitudes,but the number of Monochamus alternatus on dead pine trees in different slope direction showed a changing trend as follows:south slope>west slope>southwest slope>southeast slope>east slope>northwest slope>northeast slope>north slope.Monochamus alternatus larvae in different altitudes and slopes showed aggregation distribution.【Conclusion】The two-dimensional spatial distribution pattern of Monochamus alternatus larvae on dead pine trees was mainly affected by DBH,height and slope direction.For the control of Monochamus alternatus,corresponding strategies should be adopted according to these influencing factors,focusing on dead pine trees with large DBH,high tree body,so as to improve the control effect.