PARASITE-INDUCED RISK OF MORTALITY ELEVATES REPRODUCTIVE EFFORT IN MALE DROSOPHILA

A trade-off between sex and somatic maintenance is fundamental to life -history theory. Tests of this trade-off usually emphasize deleterious consequences of increased reproduction on life span. Here we show the reverse effect, that reductions in the expected life span elevate sex ual activity. Experimentally parasitized male Drosophila nigrospiracul a lived shorter lives, but before dying, they courted females signific antly more than unparasitized controls. This greater courtship resulte d in increased mating speed, and potentially greater reproductive succ ess than parasitized males would have achieved otherwise. The results show that an environmental reduction in life span increases reproducti ve effort, and support the hypothesis of a trade-off between these key life-history traits.