School of Environment & Sustainability; Royal Roads University; Victoria, BC Canada.
Plant Signal Behav. 2012 Oct 1;7(10):1267-70. doi: 10.4161/psb.21661. Epub 2012 Aug 20.
Three species of Nepenthes pitcher plants (Nepenthes rajah, Nepenthes lowii and Nepenthes macrophylla) specialize in harvesting nutrients from tree shrew excreta in their pitchers. In all three species, nectaries on the underside of the pitcher lid are the focus of the tree shrews' attention. Tree shrews are dichromats, with visual sensitivity in the blue and green wavebands. All three Nepenthes species were shown to produce visual signals, in which the underside of the pitcher lid (the area of highest nectar production) stood out in high contrast to the adjacent area on the pitcher (i.e., was brighter), in the blue and green wavebands visible to the tree shrews. N. rajah showed the tightest degree of "tuning," notably in the green waveband. Conversely, pitchers of Nepenthes burbidgeae, a typical insectivorous species sympatric with N. rajah, did not produce a color pattern tuned to tree shrew sensitivity maxima.
三种猪笼草（Nepenthes rajah、Nepenthes lowii 和 Nepenthes macrophylla）专门从树鼩的粪便中提取营养物质。在这三种猪笼草中，瓶盖上的蜜腺是树鼩关注的焦点。树鼩是二色视者，对蓝色和绿色波段具有视觉敏感性。所有三种猪笼草都被证明会产生视觉信号，其中瓶盖上的底面（花蜜产量最高的区域）与瓶身相邻区域（即较暗）形成高对比度，在树鼩可见的蓝色和绿色波段中显得更亮。N. rajah 表现出最紧密的“调谐”，尤其是在绿色波段。相反，与 N. rajah 同域的典型食虫物种 Nepenthes burbidgeae 的瓶身则没有产生与树鼩敏感性最大值相匹配的颜色图案。
