兰花因为它们的诡计而闻名。大多数不向它们的传粉者提供有价值的东西的兰花反而用更具回报的花或者潜在配偶的气味引诱这些传粉者。如今，8月6日发表在细胞出版社出版的《当代生物学》杂志网站上的一份报告首次揭示了一种生活在中国海南岛上的兰花通过发出一种蜜蜂用于发出警报的化学物质从而欺骗了它的传粉者胡蜂。
这项发现解释了为何人们观察到了把蜜蜂作为食物提供给幼虫的胡蜂确实猛扑向了毫无回报的华石斛（Dendrobium sinense）的花朵。
德国乌尔姆大学的研究人员Manfred Ayasse 和Jennifer Brodmann说，这种兰花制造的化合物称为Z-11-eicosen-1-ol，它在昆虫世界也是很稀有的。此前从未在任何植物中间发现它。
“当然，我们知道兰花如何吸引它们的传粉者的其他一些有趣的例子，”Ayasse说。“然而，我们没料到发现这样一种新型的诡计。”
这组科学家早先从他们的中国合作者的研究中得知，华石斛和黑盾胡蜂（Vespa bicolor）之间发生了一些事情。迄今为止，胡蜂是这些兰花的最频繁的访问者。但是这些胡蜂并没有在这些花上着陆并停顿，而是猛扑向这种花的红色中心，仿佛它们正在攻击猎物。
在如今的这项研究中，他们发现了胡蜂更倾向于接近有自然气味的兰花或者充满了这种花的气味的假蜜蜂，而不是没有气味的假蜜蜂。
对于这种花的萃取物的检查表明Z-11-eicosen-1-ol是少数可能被胡蜂工蜂的触角探测到的化合物之一。其他一些研究表明，这种化学物质是蜜蜂的警报信息素的主要成分之一，而且是狩猎的胡蜂辨识猎物的主要成分。在实验室对胡蜂的行为实验证实了这种捕食昆虫被这种兰花的气味以及Z-11-eicosen-1-ol本身所吸引。
这组科学家说，人们可能从这些兰花中学会如何为了自身的目的而操纵胡蜂。
“各种胡蜂对于养蜂人是一个问题，因为它们抢劫蜂巢，”Ayasse说。“除了这个问题，它们破坏水果作物，这让胡蜂成为了人类面临的一种严重的害虫。我们的研究结果可能用于开发对环境负责的捕捉害虫胡蜂的陷阱。”（生物谷Bioon.com）
生物谷推荐原始出处：
Current Biology, 06 August 2009 doi:10.1016/j.cub.2009.06.067
Orchid Mimics Honey Bee Alarm Pheromone in Order to Attract Hornets for Pollination
Jennifer Brodmann1,Robert Twele2,Wittko Francke2,Luo Yi-bo3,Song Xi-qiang4andManfred Ayasse1,,
1 Institute of Experimental Ecology, University of Ulm, 89069Ulm, Germany
2 Institute of Organic Chemistry, University of Hamburg, 20146Hamburg, Germany
3 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing100093, China
4 Key Laboratory of Tropical Horticultural Plant Resources andGenetic Improvement, Hainan University, Haikou570228,China
Approximately one-third of the world's estimated 30,000 orchid species are deceptive and do not reward their pollinators with nectar or pollen [1]. Most of these deceptive orchids imitate the scent of rewarding flowers or potential mates [2,3]. In this study, we investigated the floral scent involved in pollinator attraction to the rewardless orchid Dendrobium sinense, a species endemic to the Chinese island Hainan that is pollinated by the hornet Vespa bicolor. Via chemical analyses and electrophysiological methods, we demonstrate that the flowers of D. sinense produce (Z)-11-eicosen-1-ol and that the pollinator can smell this compound. This is a major compound in the alarm pheromones of both Asian (Apis cerana) and European (Apis mellifera) honey bees [4,5] and is also exploited by the European beewolf (Philanthus triangulum) to locate its prey [6]. This is the first time that (Z)-11-eicosen-1-ol has been identified as a floral volatile. In behavioral experiments, we demonstrate that the floral scent of D. sinense and synthetic (Z)-11-eicosen-1-ol are both attractive to hornets. Because hornets frequently capture honey bees to feed to their larvae, we suggest that the flowers of D. sinense mimic the alarm pheromone of honey bees in order to attract prey-hunting hornets for pollination.
