Eisner T, Goetz M A, Hill D E, Smedley S R, Meinwald J
Section of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
Proc Natl Acad Sci U S A. 1997 Sep 2;94(18):9723-8. doi: 10.1073/pnas.94.18.9723.
Female fireflies of the genus Photuris, the so-called firefly "femmes fatales," prey on male fireflies of the genus Photinus. The females are able to entrap the males by faking the flash signal characteristics of the Photinus female. We found that by feeding on Photinus males, Photuris females gain more than nutrients. They also acquire defensive steroidal pyrones called lucibufagins, which are contained in Photinus but which Photuris fireflies are unable to produce on their own. Photuris females that eat Photinus males or lucibufagin are rejected by Phidippus jumping spiders. Lucibufagin itself proved to be a deterrent to such spiders. Field-collected Photuris females contain lucibufagin in varying amounts. The more lucibufagin they contain the more unacceptable they are to Phidippus.
Photuris属的雌性萤火虫，即所谓的萤火虫“致命女人”，会捕食Photinus属的雄性萤火虫。这些雌性萤火虫能够通过模仿Photinus属雌性萤火虫的闪光信号特征来诱捕雄性萤火虫。我们发现，通过捕食Photinus属雄性萤火虫，Photuris属雌性萤火虫获得的不仅仅是营养物质。它们还获取了一种名为卢西 Bufagin 的防御性甾体吡喃酮，这种物质存在于Photinus属萤火虫体内，但Photuris属萤火虫自身无法产生。食用了Photinus属雄性萤火虫或卢西 Bufagin 的Photuris属雌性萤火虫会被Phidippus跳蛛拒食。事实证明，卢西 Bufagin 本身对这类蜘蛛具有威慑作用。野外采集的Photuris属雌性萤火虫体内含有不同量的卢西 Bufagin。它们所含的卢西 Bufagin 越多，对Phidippus跳蛛来说就越不可接受。
