Federle Walter, Maschwitz Ulrich, Fiala Brigitte, Riederer Markus, Hölldobler B
Zoologie II, Universität Würzburg, Biozentrum, Am Hubland, D-97074 Würzburg, Germany, , , , , , DE.
Zoologisches Institut, J.W. Goethe Universität, Siesmayerstr.70, D-60054 Frankfurt, Germany, , , , , , DE.
Oecologia. 1997 Oct;112(2):217-224. doi: 10.1007/s004420050303.
In many ant-plant species of the genus Macaranga in South-East Asia, conspicuous blooms of epicuticular wax crystals cover the stem surface. We found that many ant species were unable to walk on these surfaces. Only the specific ant partners of glaucous Macaranga host plants were capable of moving on the slippery stems without difficulty. Therefore, the epicuticular coatings of Macaranga myrmecophytes appear to have a selective function and protect the associated ants against competitors. The epicuticular aggregates function as a physical barrier; no evidence of chemical repellence was found. The extent to which "foreign" ant species are excluded from a tree strongly depends on inclination, diameter and length of the glaucous stem sections. The particular growth form of some glaucous Macaranga ant-plants enhances the influence of the wax barriers. The ant associates of glaucous and glossy Macaranga ant-plants (genera Crematogaster and Camponotus) differ strongly in their capacity to adhere to the glaucous stems. For this reason, the wax blooms in Macaranga can act as an ecological isolation mechanism for the sympiotic ants. Within the genus Macaranga, we find a high correspondence between the occurrence of glaucousness and obligatory ant association (50% in ant-plants; 6.7% in non-myrmecophytes). The genus Macaranga thus represents one of the few cases known so far where epicuticular wax crystals are likely to have evolved in relation to insects.
在东南亚许多大戟属的蚁栖植物物种中，茎表面覆盖着明显的表皮蜡晶花簇。我们发现许多蚂蚁物种无法在这些表面行走。只有大戟属灰白色寄主植物的特定蚂蚁伙伴能够毫无困难地在光滑的茎上移动。因此，大戟属蚁栖植物的表皮涂层似乎具有选择功能，并保护相关蚂蚁免受竞争者侵害。表皮聚集体起到物理屏障的作用；未发现化学排斥的证据。“外来”蚂蚁物种被排除在树上的程度在很大程度上取决于灰白色茎段的倾斜度、直径和长度。一些灰白色大戟属蚁栖植物的特殊生长形式增强了蜡质屏障的影响。灰白色和有光泽的大戟属蚁栖植物（ Crematogaster属和Camponotus属）的蚂蚁伙伴在附着于灰白色茎的能力上有很大差异。因此，大戟属植物上的蜡花簇可以作为共生蚂蚁的一种生态隔离机制。在大戟属内，我们发现灰白色的出现与 obligatory蚂蚁关联之间存在高度对应关系（蚁栖植物中为50%；非蚁栖植物中为6.7%）。因此，大戟属代表了迄今为止已知的少数几个案例之一，即表皮蜡晶可能是与昆虫相关而进化的。
