不同生境中沙冬青豆荚螟的危害率及空间分布型

Damage Rate and Spatial Distribution Type of Etiella zinckenella on Ammopiptanthus mongolicus in Different Habitats

豆荚螟(Etiella zinckenella)是沙冬青(Ammopiptanthus mongolicus)种子的主要害虫。在宁夏灵武白芨滩国家自然保护区内选择了沙冬青自然生长(羊场湾样地、枣泉样地)和人工栽植(甜水河样地、马鞍山样地)2类生境的4个试验样地,调查了沙冬青豆荚螟幼虫的危害情况,研究了其空间分布型。结果表明:豆荚螟幼虫数量(2.015只·荚-1)、对豆荚的为害率(82.83%)在马鞍山样地最高,其次是甜水河样地(1.423 3只·荚-1,64.83%)和羊场湾样地(1.218 3只·荚-1,59.83%),枣泉样地最低(0.558 5只·荚-1,32.00%),豆荚螟幼虫的数量和为害率在人工栽植生境显著高于自然散生生境,与沙冬青的种群密度呈正相关。基于频次分布指标、聚集度指标及回归分析显示,不论在人工栽植生境还是自然生长生境中沙冬青豆荚螟幼虫的空间分布型均呈聚集分布。沙冬青豆荚螟幼虫Iwao线性回归方程为M*=1.040 66+0.569 02 M(R=0.925 1),表明沙冬青种子害虫豆荚螟个体间相互吸引,种群分布的基本成分为个体群。

Etiella zinckenellais one of main pests of Ammopiptanthus mongolicus.Taking the desert landscape in Ningxia Lingwu Baijitan Nature Reserves as the background,four plots of A.mongolicus lands with the habitat types of natural growing（Yangchangwan plot,YCW;Zaoquan plot,ZQ）and artificial planting（Tiangshuihe plot,TSH;Ma′anshan plot,MAS）were selected as study sites to investigate the damage rate and its spatial distribution type of E.zinckenella.The results showed that larva individual and damage rate of E.zinckenellain MAS was the highest（2.015 individuals per pod,82.83%）,followed by the TSH（1.423 3individuals per pod,64.83%）and YCW（1.218 3individuals per pod,59.83%）.ZQ was the lowest（0.558 5individuals per pod,32.00%）.Artificial planting habitats were significantly higher than natural growing habitats.The individual number and damage rate of E.zinckenellawas positively correlated with the density of A.mongolicus.Based on multiple stepwise regression analysis,damage rate were positively correlated with the length,breadth and number of seed of per pod.Based on frequency distribution indices,aggregation analysis indices and regression analysis showed that spatial distribution pattern of E.zinckenella larvae were belong to aggregating distribution regardless of in artificial planting habitats or natural growing.The Iwao model of larvae of E.zinckenella was M＊=1.040 66＋0.569 02 M（R=0.925 1）,indicated that basic composition of the E.zinckenella distribution was individual population.And the different individual had mutual affinity with each other.