The dark side of firefly sex

Flashy males may get the women but they stand an even greater chance of becoming some one else's dinner. To bad that's not true in the human world - just kidding. But it is true in the world of fireflies. A study out today from biologists at Tufts University has discovered a dark side lurking behind the magical light-shows put on by fireflies, also known as Lightning Bugs, most summer nights in many parts of the country.

On summer evenings, male Photinus fireflies fly into the air to broadcast their bioluminescent flashes in search of some female action. Females perched in the grass sit and admire passing males and, if they're interested, will flash in response Tufts said in a statement.

Previous research on many different firefly species has shown that females respond more readily to males that give longer flashes, as well as those with faster flash rhythms - isn't this always the case? Anyway, this female choice favors firefly males that produce more conspicuous flashes, researchers said.

The problem is that while those more conspicuous flash signals provide male fireflies with an evolutionary leg up in terms of attracting females, they also have a potentially fatal downside because they are more likely to attract predators - birds or even other predatory fireflies - in search of their next meal. Tufts said Photinus fireflies are known to produce noxious chemicals that deter most predators. It is the firefly's light-producing chemical that has a bitter taste. Some predators have learned how to avoid this chemical, by eating a firefly headfirst and discarding the abdomen. Others, such as frogs and spiders, eat fireflies readily.Anyway, the chemical makes them the top menu choice for the larger predatory fireflies known as Photuris.

Other studies in fact have shown that Photuris females will flash at Photinus fireflies (no words on how they know the difference) to let them come close so they can have a nosh. Cornell researchers said the females aren't necessarily being cruel, but rather male Photinus fireflies contain defensive chemicals that females need to repel predators, such as spiders. Mimicry and murder provide a lifesaving meal, Cornell researchers report in the Proceedings of the National Academy of Sciences. Of course there probably some heartbreakers out there who just go after these poor, helpless males for fun. There's no proof of that of course.