Lethal coupling

online) offers the first evidence that males of one species of spider undergo programmed death immediately following mating and consider the potential adaptive significance of such an unusual behaviour. The two researchers have been studying a species in the cannibalistic genus of orb-weaving spider, Argiope, where there has been some suggestion males may die after mating. But now the researchers have provided evidence for this. Mating is a complex business for these spiders. The pedipalps, the pair of extremities posterior to the fangs, are morphologically derived to function as copulatory organs. Each palp inserts into one of the female's paired genital openings, which lead to separate sperm storage organs. On insertion, the distal bulb of the palp is inflated through increase in haemolymph pressure, which leads to the coupling of the palp with the female's genital plate. In the species studied, A. aurantia, males pursue two alternative mating strategies: if they encounter a juvenile female, one moult away from adulthood, they may cohabit with her on her web. They then try the two-stage Death by design: Could the males of the orb-weaving spider, Argiope aurantia, be programmed to die immediately after copu-lation? New research suggests that they can.