Interdependency of nutrition and oxidative stress in feeding and resource allocation

Animals are regularly exposed to oxidative stress (OS) through normal biological processes, such as reproduction and aging, and they increasingly experience OS due to environmental change. However, the fitness-related costs of OS may be mediated by dietary options and feeding decisions. Here, we used a nutritional geometry framework in female field crickets (Gryllus lineaticeps) to examine the interplay between dietary macronutrients (protein [P] and carbohydrate [C]) and OS related to feeding and allocation to life-history traits. During OS (paraquat exposure), females ate more food and allocated fewer ingested nutrients to ovaries in a low-quality diet, but they ate less food and allocated more toward ovaries when dietary options were available. Overall, exposure to OS promoted reproduction at an expense to self-maintenance. Because the macronutrient quality (P:C) of available foods is declining due to climate change, nutrition and feeding decisions may play important roles in mediating how OS shapes life-history tradeoffs.