Department for Neurobiology, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090, Vienna, Austria.
J Chem Ecol. 2011 Sep;37(9):953-60. doi: 10.1007/s10886-011-0010-9. Epub 2011 Aug 24.
Male neotropical orchid bees (Euglossini) collect volatile chemicals from their environment, store them in tibial pouches, and later expose their "perfumes" during a courtship display. Here, we showed that enantiomeric selectivity plays an important role in the choice of volatiles by male Euglossa cyanura in southern Mexico, and that behavioral selectivity is linked to antennal sensitivity. In field bioassays with equal concentrations of (+)-ipsdienol, (-)-ipsdienol, and racemate, males preferred the (-)-isomer to the racemate, while neglecting the (+)-isomer. Correspondingly, antennae of male E. cyanura showed larger electroantennographic responses to the (-)-isomer than to the (+)-isomer. In comparison, antennae of male Euglossa mixta, which are not attracted to any form of ipsdienol, showed lower electroantennographic responses to (-)-ipsdienol than did antennae of E. cyanura, and also did not differ in sensitivity with respect to the (+)- or (-)-isomers. We suggest that (-)-ipsdienol is an important component of perfume signals in male E. cyanura, which have undergone selection in favor of increased antennal sensitivity to that enantiomer.
雄性新热带兰花蜂（Euglossini）从环境中收集挥发性化学物质，将其储存在胫骨囊中，然后在求偶展示中暴露它们的“香水”。在这里，我们表明对映体选择性在墨西哥南部雄性 Euglossa cyanura 对挥发物的选择中起着重要作用，并且行为选择性与触角敏感性有关。在野外生物测定中，使用等量的（+）-ipsdienol、（-）-ipsdienol 和外消旋体，雄性更喜欢（-）异构体而不是外消旋体，而忽略了（+）异构体。相应地，雄性 E. cyanura 的触角对（-）异构体的电触角反应大于对（+）异构体的电触角反应。相比之下，对任何形式的 ipsdienol 都没有吸引力的雄性 Euglossa mixta 的触角对（-）-ipsdienol 的电触角反应比 E. cyanura 的触角低，并且对于（+）或（-）异构体的敏感性也没有差异。我们认为（-）-ipsdienol 是雄性 E. cyanura 香水信号的重要组成部分，它们已经经历了选择，以增加对该对映体的触角敏感性。
