Bach Catherine E
Division of Biological Sciences, University of Michigan, 48109, Ann Arbor, MI, USA.
Oecologia. 1986 Mar;68(4):580-584. doi: 10.1007/BF00378774.
The effects of host plant patch size on the abundances of two specialist herbivores (the chrysomelid beetle, Acalymma innubum and the pentatomid bug, Piezosternum subulatum) were investigated in a natural forest community in the Virgin Islands. Abundances were compared early and late in the season in different sized patches of the cucurbit host plant (Cayaponia americana) growing in open habitat (with no surrounding plant community) and forest habitat (with diverse surrounding plant community). For both herbivore species, adult abundances per patch were positively correlated with patch leaf area, but there was a significant patch size effect (i.e., correlation between herbivore density per unit plant and patch leaf area) only for beetles in the forest habitat. Both herbivore species were significantly affected by surrounding plant diversity, but in opposite ways: beetles were more abundant in open patches whereas bugs were more abundant in forest patches. Relationships between abundance and patch size in open and forest patches changed through the season for both herbivore species. These changing abundance patterns are discussed with respect to (1) increases in the diversity of the plant community surrounding host plant patches, and (2) differences in herbivore movement patterns.
在美属维尔京群岛的一个天然森林群落中，研究了寄主植物斑块大小对两种专食性食草动物（叶甲科甲虫，Acalymma innubum和蝽科臭虫，Piezosternum subulatum）数量的影响。在开放栖息地（无周围植物群落）和森林栖息地（有多样的周围植物群落）中，对不同大小的葫芦科寄主植物（美洲卡亚波尼草，Cayaponia americana）斑块在季节早期和晚期的数量进行了比较。对于这两种食草动物物种，每个斑块中的成虫数量与斑块叶面积呈正相关，但仅对森林栖息地中的甲虫存在显著的斑块大小效应（即单位植物上的食草动物密度与斑块叶面积之间的相关性）。两种食草动物物种均受到周围植物多样性的显著影响，但方式相反：甲虫在开放斑块中更为丰富，而臭虫在森林斑块中更为丰富。对于这两种食草动物物种，开放斑块和森林斑块中数量与斑块大小之间的关系在整个季节中都会发生变化。针对（1）寄主植物斑块周围植物群落多样性的增加，以及（2）食草动物移动模式的差异，对这些不断变化的数量模式进行了讨论。
