A diagram of our experimental mating design. We mated females at either a young age (7 days after eclosion to adulthood) or an old age (25 days after eclosion to adulthood) for two subsequent generations, then measured three proxies of reproductive investment in males of the F3 generation. The F3 families from the Old treatment were the offspring of 8 founding females and the F3 families from the Young treatment were the offspring of 7 founding females.