Female fireflies' fatal attraction

NATURE: Briefing

Femme fatale fireflies tempt males of a different species by pretending to be their mates and then have them for breakfast, scientists at Cornell University, Ithaca, New York, have discovered. The female Photuris fireflies attract their victims with a flashing light "password". It is the same signal the female of the Photinus family uses to entice a mate, but not as welcoming.

In fact, the male Photinus flies come to a sticky end. The Photuris females are not looking for a loving embrace but for something to eat. The male Photinus has defensive chemicals in his blood the Photuris needs to repel predators like spiders and birds.

By devouring the hapless Photinus male, the female Photuris arms herself with the vital chemical. Experiments showed that when Photuris fireflies have eaten Photinus fireflies, hungry spiders reject them.

The findings were published in the journal Proceedings of the National Academy of Sciences.