贺兰山榆跳象幼虫空间分布特征及影响因子分析  

Spatial distribution pattern of the larvae of Orchestes alni and influence factors in Helan Mountains

作　　者：李欣芸 冯亚萍 安旭 杨贵军[1] LI Xin-Yun;FENG Ya-Ping;AN Xu;YANG Gui-Jun(School of Life Sciences,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学生命科学学院,银川750021

出　　处：《应用昆虫学报》2020年第2期450-459,共10页Chinese Journal of Applied Entomology

基　　金：国家自然科学基金项目(31760618;31360511)。

摘　　要：【目的】明确贺兰山榆跳象Orchestesalni幼虫空间分布型及其形成机制,分析影响榆跳象幼虫空间分布的因子,以期为榆跳象的预测预报及防控措施提供参考。【方法】对贺兰山灰榆林榆跳象幼虫平均密度进行调查,应用6种聚集度指标法和2种回归模型法分析榆跳象幼虫的空间分布型。【结果】贺兰山中部沟道灰榆榆跳象幼虫密度明显高于南北沟道。半阴坡和阴坡榆跳象幼虫平均密度显著高于阳坡和沟道。灰榆树冠不同方向的幼虫平均密度差异不显著,以树冠中下层最大。榆跳象幼虫密度与树干高呈显著正相关。榆跳象幼虫在贺兰山灰榆林中呈聚集分布,基本成分是个体群,个体间相互吸引,并随种群密度升高,聚集程度增大。聚集分布是由昆虫行为或环境条件引起。灰榆林海拔和坡度显著影响榆跳象幼虫密度,榆跳象幼虫主要聚集在海拔1800 m以上(29.00%)和急坡(24.08%)的灰榆林。【结论】贺兰山中部沟道的中海拔区域是榆跳象发生的重点监测区域,背风且水分条件好的坡向密度大,榆跳象幼虫聚集分布容易造成局部区域密度较高。[Objectives]To analyze the spatial distribution of Orchestes alni larvae and identify factors useful for forecasting and controlling this pest.[Methods]The ratio of infested grey elm trees and the population density of the O.alni were quantified in the Helan Mountains.The spatial distribution of O.alni larvae was investigated using six aggregation indices and regression analysis.[Results]The ratio of infested elm trees in the center of the Helan Mountains was obviously higher than in northern and southern parts.Significantly more larvae were found on semi-shady slopes and more were found on shady slopes than on sunny slopes and valleys.The highest densities were in the lower crowns of grey elm trees,but height and aspect otherwise had no significant effect on abundance.There was a significant positive correlation between larval damage and elm height.Larvae had an aggregated spatial pattern and the basic unit was individual groups.The spatial pattern was density dependent;i.e.aggregation increased with population density.Aggregation was the result of behavior and environmental conditions.The abundance of larvae in grey elm forest was significantly affected by elevation and slope;larvae were mainly concentrated on steep slopes above 1800 m.[Conclusion]Mid elevation valleys in the central the Helan Mountains are the key areas for monitoring the occurrence of O.alni larvae.Larval density was higher on sheltered,semi-cloudy slopes with good water.The aggregated distribution of O.alni larvae can easily cause high local densities.

关 键 词：榆跳象幼虫 空间分布 灰榆 地形 贺兰山 

分 类 号：S763.38[农业科学—森林保护学]