A mortality cost of virginity at older ages in female Mediterranean fruit flies.

Mortality rates were measured over the lifetime of 65,000 female Mediterranean fruit flies, Ceratitis capitata, maintained in either all-female (virgin) cages or cages with equal initial numbers of males, to determine the effect of sexual activity and mating on the mortality trajectory of females at older ages. Although a greater fraction of females maintained in all-female (virgin) cages survived to older ages, the life expectancy of the surviving virgins was less than the life expectancy of surviving non-virgins at older ages. This was due to a mortality crossover where virgin flies experience lower mortality than mated flies from eclosion to Day 20 but higher mortality thereafter. These results suggest that there are two consequences of mating--a short-term mortality increase (cost) and a longer term mortality decrease (benefit).