Data from: Revisiting the link between breeding effort and oxidative balance through field evaluation of two sympatric sibling insect species

The idea that oxidative stress could be a major force governing evolutionary trade-offs has recently been challenged by experimental approaches in laboratory conditions triggering extensive debates centered on theoretical and methodological issues. Here, we revisited the link between oxidative stress and reproduction by measuring multiple antioxidant and oxidative damages in wild-caught females of two sibling weevil species (Curculio elephas, C. glandium). The strength of our study arises from: (1) studied species are sympatric and exploit similar resource but display contrasting reproductive strategies and (2) individuals were sampled throughout adult life so as to relate oxidative status to breeding effort. We found that the short-lived C. elephas sacrifices red-ox homeostasis for immediate reproduction upon emergence as characterized by low antioxidant defenses and elevated oxidative damage. Comparatively, C. glandium massively invests in antioxidant and maintains low oxidative damage, which may contribute to their extended pre-reproductive period. Intriguingly, we also reveal, for the first time in a field study, an unexpected reactivation of antioxidant defenses with the onset of reproduction. Our results thus support the existence of a strong but complex relationship between oxidative stress and life history evolution and highlight the need for a finer-scale picture of antioxidant strategies.氧化应激（oxidative stress）可能是支配进化权衡的核心力量这一观点，近日受到实验室条件下实验研究的挑战，引发了围绕理论与方法论议题的广泛争议。本研究重新审视了氧化应激与繁殖之间的关联，对两种近缘象鼻虫（Curculio elephas、C. glandium）的野生捕获雌虫的多项抗氧化指标与氧化损伤水平进行了测定。本研究的优势在于：其一，所研究的物种为同域分布类群，利用相似的资源却展现出迥异的繁殖策略；其二，样本采集覆盖了成虫整个生命周期，从而能够将氧化状态与繁殖投入相关联。研究发现，寿命较短的C. elephas在羽化后即刻开展繁殖时，会以牺牲氧化还原稳态（red-ox homeostasis）为代价，表现为抗氧化防御能力低下且氧化损伤水平升高。与之相对，C. glandium会大量投入抗氧化防御机制，并维持较低的氧化损伤水平，这或许有助于其延长繁殖前期。值得注意的是，本研究还在野外研究中首次揭示了一项意外发现：随着繁殖活动启动，抗氧化防御能力会出现意料之外的重新激活。综上，本研究结果支持氧化应激与生活史进化（life history evolution）之间存在紧密却复杂的关联，并强调需要对抗氧化策略开展更精细化的解析。