Femme Fatale or Tiger Fireflies

     While fireflies signal to each other and want to be noticed by other fireflies of the opposite sex, they sometimes attract the unwanted attention of the wrong fireflies. Some of these fireflies have ulterior motives. There is a whole genus of fireflies, the Photuris, or Tiger Fireflies, that are looking for other fireflies in order to eat them. These are larger than most others and you can usually see their whole heads and eyes protruding from under their pronotum, or shield-like appendage that covers the necks and heads, unlike many other fireflies.

     Sometimes they just look for signalling fireflies (generally the males since they are the ones flying) and swoop down to capture them. Other times though, they have a much more devious way of catching their prey. They can actually mimic the light signals of some other fireflies to lure them in. These femme fatales then eat the confused suitor. 

Tiger Fireflies feeding on other fireflies.

     It is thought that a Photuris firefly can consume quite a few other fireflies (mostly in the Genus Photinus) during each night. They've been known to eat their own males, who also sometimes imitate the Photinus to lure the females in, and eat any firefly caught in a spider's web. They also can sequester the toxic alkaloids these other fireflies use to protect themselves to then protect the Tiger Firefly itself. Fireflies, like ladybugs, secrete protective chemicals from the joints of their legs in a process called "reflex bleeding." In addition to flashing to attract mates, all glowwworm (immature) stages of fireflies can flash, as well many adults, some eggs, and even some pupae, and this is thought to also serve as a warning signal of their distastefullness to predators. Photuris need to obtain these protective chemicals from other fireflies. Their own species-specific flashes that they use to attract their mates are usually green as opposed to the yellow of the more common Photinus fireflies they prey upon, with at least one species producing a triple flash. One species of these femme fatale fireflies (there are thought to be 28 species in North America, though this is constantly being revised), the Pennsylvania Firefly (Photuris pennsylvanica) is the state insect of Pennsylvania since 1974. Another, the Bethany Beach Firefly (Photuris bethaniensis) is considered to be the most endangered firelfy in the world with a 20-mile stretch of freshwater sand dune beaches as its habitat. Another, Photuris frontalis, synchronizes its flash all at once in the South forming beautiful dipslays in such places as the Smokies.  

     So there are a lot flashers out there trying to attract mates in the firefly world. However, there isn't just seduction going on. There are also femme fatales out there luring males to their deaths, feeding and stealing from them what they need to survive. Such is the intrigue of the natural world at night, where everything is not as it seems and even beauty can have hidden dangers.