In North America, if you see a classic spiderweb with a dense, zigzag thread through its center, the web could well have been spun by Argiope aurantia. Even more striking than the web, though, is the species' sexual politics: for the male, copulation is suicide.

Other male spiders die during mating, but that's because the females kill and eat them. Evolutionary biologists Matthias W. Foellmer of Concordia University in Montreal and Daphne J. Fairbairn of the University of California, Riverside, have now determined that in A. aurantia the males themselves are programmed to undergo sudden death--attacked or not.

Whether his partner is a defenseless, molting juvenile or a consenting though potentially aggressive adult, the male goes into his death throes within moments of inserting the second of his two pedipalps (mating appendages) inside the second of the female's two genital apertures. Once that pedipalp inflates, it's curtains for the guy. Within fifteen minutes--and usually sooner--his heart stops, even when the female is prevented (by experimenters) from molesting him. A further bit of proof that death occurs without female complicity: one male, after inserting his first pedipalp in the normal place, moved elsewhere on the female's web and inexplicably inserted his second pedipalp into a nearby dead mealworm. He died instantly--and not of shame at his mistake.