Longevity of free-living female adult bowl and doily spiders was compared with that of captive spiders fed at dietary regimes of one, three, and five Drosophila melanogaster per week. Adult females lived, on average, only 8 days in the field and the pattern of survivorship showed no evidence that senescence contributed to mortality. In the laboratory, mean adult life span was 81.3, 63.9, and 42.3 days on the one, three, and five Drosophila diets, respectively. Decreased feeding rate also delayed egg laying and reduced total fecundity. Survival and reproductive patterns indicated the manifestation of spider senescence at all laboratory feeding levels, with a younger onset of senescence at the higher feeding rates. © 1989.