Matter Stephen F
The Blandy Experimental Farm, Boyce, VA 22620, USA, , , , , , US.
Oecologia. 1997 May;110(4):533-538. doi: 10.1007/s004420050191.
The relationship between population density and the size of host plant patches was investigated for the red milkweed beetle Tetraopestetraophthalmus inhabiting unmanipulated patches of Asclepias syriaca. The resource concentration hypothesis proposes that density-area patterns, specifically that of increasing herbivore density with patch size, are primarily a function of movement between host plant patches. This research investigated the degree to which movement accounted for density-area patterns. Poisson regression analysis of beetle abundance versus milkweed patch size revealed that beetle density tended to increase with patch size. The pattern of density and patch size resulted from local reproduction and residence time. The density of emerging beetles tended to increase with patch size while emigration rates were unrelated to patch size. Immigration rates were constant with patch size for male beetles, and decreased with patch size for female beetles. Net flux of beetles (immigration - emigration) did not vary with patch size for male beetles and decreased with patch size for female beetles. Comparisons are made between this system and previously studied systems where movement plays a significant role in forming density area patterns. Additionally, several hypotheses are presented which may account for greater in situ recruitment and residence time in large patches.
研究了居住在未经人工干预的叙利亚马利筋斑块中的红斑马利筋甲虫（Tetraopes tetraophthalmus）的种群密度与寄主植物斑块大小之间的关系。资源集中假说提出，密度-面积模式，特别是食草动物密度随斑块大小增加的模式，主要是寄主植物斑块之间移动的函数。本研究调查了移动对密度-面积模式的影响程度。对甲虫丰度与马利筋斑块大小进行泊松回归分析，结果显示甲虫密度倾向于随斑块大小增加。密度和斑块大小的模式是由本地繁殖和居留时间导致的。新羽化甲虫的密度倾向于随斑块大小增加，而迁出率与斑块大小无关。雄甲虫的迁入率随斑块大小保持不变，雌甲虫的迁入率随斑块大小降低。雄甲虫的甲虫净通量（迁入-迁出）不随斑块大小变化，雌甲虫的甲虫净通量随斑块大小降低。将该系统与先前研究的系统进行了比较，在先前的系统中，移动在形成密度-面积模式中起重要作用。此外，还提出了几个假说，这些假说可能解释了在大斑块中更高的原地补充率和居留时间。
