Sex- and trait-specific silver-spoon effects of developmental environments, on ageing

The environment organisms experience during development can have effects which carry over into their adult lives. These environments not only affect adult traits at a given point in time, but also how these traits change with age. Generally, favorable developmental environments lead to more optimal adult traits while stressful environments are deleterious (“silver-spoon effect”). But whether developmental environments affect how whole-organism performance traits change with age or whether they affect males and females differently lacks evidence. Here, we test whether experiencing favorable developmental environments leads to “silver-spoon effects” on life-history traits and whole-organism flight performance of males and females by manipulating developmental density in Callosobruchus maculatus. We further test whether such effects are mediated by an individual’s reproductive status by comparing traits of mated versus virgin females. We show that although developmental crowding has no effect on flight performance of either sex, on male adult lifespan, or on female age-dependent survival, it is detrimental to female lifespan and fecundity, as well as female age-dependent reproduction, suggesting that females are more sensitive to differences in developmental density. Additionally, we show that flight traits change with age and differ not only between males and females, which is reflective of sex-specific life-histories and behavior, but also between virgin and mated females. Our study is important for understanding sex-specific responses to developmental environments in life-history, behavioral, and ecologically important traits which may affect resource allocation, dispersal, and mating strategies, hence fitness.