Universität Hohenheim, Institut für Zoologie, Tierökologie 220c, Garbenstraße 30, 70593, Stuttgart, Germany.
J Chem Ecol. 2012 Dec;38(12):1493-503. doi: 10.1007/s10886-012-0215-6. Epub 2012 Dec 8.
The twisted-wing parasites (Strepsiptera) are an unusual and small order of insects with about 600 known species. As obligate endoparasitoids, they develop and spend most of their lives living in other insects. Adults show an extreme sexual dimorphism: The free-living males have large eyes, branched antennae, reduced forewings, and well developed hind wings, while the neotenic females of most species lack all external characters that normally define an insect, remain endoparasitic, and only extrude the cephalothorax from the host. Due to the males' short life span of only a few hours, there must be an efficient means of mate finding. This is believed to be mediated by chemical cues released by virgin females. Here, we report the first identification and synthesis of a female-produced strepsipteran sex pheromone, (3R,5R,9R)-3,5,9-trimethyldodecanal, from Stylops melittae, a species parasitizing andrenid bees. We found this highly EAD-active compound to be present in cephalothoraxes of and released from unmated females, and synthetic samples proved to be extremely attractive when offered in the field during the swarming period of the males. The structural features of this new natural compound may further support the re-establishment of the Strepsiptera as the closest living relatives of the Coleoptera.
捻翅目（Strepsiptera）是一种不寻常的小型昆虫目，已知约有 600 种。作为专性内寄生性寄生蜂，它们在其他昆虫体内发育并度过大部分生命。成虫表现出极端的性二态性：自由生活的雄性具有大的眼睛、分枝的触角、退化的前翅和发育良好的后翅，而大多数物种的幼态雌性则缺乏通常定义昆虫的所有外部特征，仍然是内寄生的，只将头胸部从宿主中伸出。由于雄性的寿命只有几个小时，因此必须有一种有效的交配方法。据信，这是通过处女雌性释放的化学线索来介导的。在这里，我们报告了第一个从寄生在蚂蚁上的物种 Stylops melittae 中鉴定和合成的捻翅目性信息素，即（3R，5R，9R）-3，5，9-三甲基十二烷醛。我们发现这种高 EAD 活性化合物存在于未交配雌性的头胸部中，并从其中释放出来，并且当在雄性群集期间在野外提供合成样品时，它们具有极强的吸引力。这种新的天然化合物的结构特征可能进一步支持将捻翅目作为最接近鞘翅目（Coleoptera）的活亲缘关系的重新确立。
