Abstract Resource allocation trade-offs, like that between flight and fecundity, are central to the ecology and evolution of all animals and plants. Yet, research on trade-offs has traditionally focused on a single moment during ontogeny, overlooking how the continuous acquisition of resources might modulate these trade-offs. This is especially important for organisms with complex life cycles, like butterflies, which acquire nutrients from different sources as larvae and adults. Our study on the cabbage butterfly, Pieris rapae, investigated how limited larval nitrogen impacts allocation to flight versus fecundity and whether adult feeding could obviate such trade-off. Using gravimetric measurements and stable isotope tracing, we uncovered a complex, sex-specific link between early-life nutrition and adult resources. While flight–fecundity trade-offs were evident in both sexes, only females appeared to use adult resources to ameliorate the negative effects of poor larval nutrition. Females achieved this by incorporating newly acquired nectar nutrients while reallocating larval nutrients. In contrast, males unexpectedly thrived under nitrogen limitation but were more constrained by their adult diet. By studying trade-offs as dynamic processes, this study captured a complex interplay between early and adult life that may ultimately shape this species’s role as both an herbivore and a pollinator.
Tigreros et al. (Wed,) studied this question.