Fox Laurel R, Macauley B J
Department of Environmental Biology, Research School of Biological Sciences, Box 475, 2601, Canberra City, A.C.T., Australia.
Oecologia. 1977 Jun;29(2):145-162. doi: 10.1007/BF00345794.
Many species of Eucalyptus, one of the dominant genera in Australian forests and woodlands, contain high levels of tannins and other phenols and are also heavily damaged by grazing insects. These phenols do not appear to affect insect attack because a wide range of concentrations of condensed tannins and other phenols in leaves of 13 Eucalyptus sp. influenced neither feeding rates of Paropsis atomaria larvae, nor their nitrogen use efficiencies. We discuss reasons why tannins may not appreciably reduce the availability of nitrogen (N) to these insects. Performance was directly related to leaf N concentration, and growth rates, N gains, and N use efficiencies all increased as leaf N content increased, although absolute feeding rates remained constant. These relationships differ from those found in insects feeding on other plants, and we suggest that the low N contents common in Eucalyptus leaves may be responsble. We propose that the extensive damage observed in many eucalypts is in part related to the high feeding rates maintained by individual larvae.
桉树是澳大利亚森林和林地中的主要属之一，许多桉树物种含有高含量的单宁和其他酚类物质，并且也受到食草昆虫的严重破坏。这些酚类物质似乎不会影响昆虫的攻击，因为13种桉树叶中不同浓度的缩合单宁和其他酚类物质既不影响黄斑肖叶甲幼虫的取食率，也不影响它们的氮利用效率。我们讨论了单宁可能不会显著降低这些昆虫可利用氮（N）的原因。生长表现与叶片氮浓度直接相关，随着叶片氮含量的增加，生长速率、氮摄入量和氮利用效率均增加，尽管绝对取食率保持不变。这些关系与以其他植物为食的昆虫不同，我们认为桉树叶中常见的低氮含量可能是原因所在。我们提出，在许多桉树上观察到的广泛损害部分与单个幼虫保持的高取食率有关。
