Firefly femmes fatales acquire defensive steroids (lucibufagins) from their firefly prey.
Body LBG* content of field-collected male and female fireflies, plotted as a function of date of collection (Ithaca, NY); n = 10 per column, except where otherwise indicated. Note: P. marginellus appears later in the season than the other two fireflies, accounting for the absence of samples of this species for most of June.
* LBG = a chemical class of cardiotonic steroids known as “lucibufagins.” These compounds are structurally similar to steroids produced by Chinese toads (Bufo spp.), which are known to be toxic to many vertebrates. The name “lucibufagin” is a combination of the name of the chemical that produces the light in fireflies (lucferin) and the toad’s name (bufo).
Image Credit: Figure from Eisner et al. (1997) Proceedings of the National Academy of Sciences (USA) 94: 9723–9728. Copyright © 1997 National Academy of Sciences, U.S.A. Used with permission.
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