In organisms, the energy allocated to different functions, such as between survival and reproduction, can vary according to biotic and/or abiotic constraints, resulting in trade-offs between associated life history traits. Life history strategies adopted by organisms depend notably on their position along the Capital-Income Breeder Continuum (CIBC). Resources invested into reproduction by pure capital breeders fully originate from capital reserves acquired during their development whereas they are only acquired through food intakes as adults in pure income breeders. However, the impact of food quality on the position of organisms along the CIBC has scarcely been considered. Nectar constitutes a major energetic resource for many holometabolous insects, favoring overall adult fitness. We tested the hypothesis that nectar quality may modify the position of individual insects along the CIBC by changing the origin of energy needed to complete egg maturation after female emergences. For that, we measured different life-history traits of the parasitoid Aphidius rhopalosiphi (Hymenoptera; Braconidae) fed with the floral nectar of three species (buckwheat, cornflower and mustard) known as presenting contrasted carbohydrate proportions, as well as water and sucrose as control solutions. We showed that buckwheat- and sucrose-fed females had both a greater longevity and a higher egg maturation rate. Sucrose- and cornflower nectar-fed females of three days-old produced bigger eggs, demonstrating that plasticity in egg traits in response to food quality is possible in koinobiont parasitoids. Our results highlight the importance of resource quality on the energy allocation strategy between key life history traits. The position of female parasitoids along the Capital-Income breeder continuum may vary according to their ability to handle different quality of sugar resources, which may decrease the reliance on capital reserves into reproductive functions. Consequently, we propose to include resource quality to the CIBC conceptual framework in future studies on life history strategies adopted by these organisms.

中文翻译：

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花蜜的品质如何影响寄生性黄蜂的生活史策略？

在生物体中，分配给不同功能（例如在生存和繁殖之间）的能量可能会根据生物和/或非生物限制而变化，从而在相关的生活史特征之间进行权衡。生物体采用的生命史策略尤其取决于其在首都-收入繁殖者连续体（CIBC）中的位置。纯资本育种者投入生殖的资源完全来自其发展过程中获得的资本储备，而纯收入育种者仅通过成年后的食物摄入获得资本储备。然而，几乎没有考虑到食品质量对CIBC沿线生物位置的影响。花蜜是许多全代谢昆虫的主要能量资源，有利于成年后的整体健康。我们检验了以下假设：花蜜质量可能会通过改变雌性出苗后完成卵成熟所需的能量来源来改变CIBC上单个昆虫的位置。为此，我们测量了以三种不同的花蜜（荞麦，矢车菊和芥末）为食的寄生性蚜虫蚜虫（Hymenoptera； Braconidae）的不同生活史特征，这些花蜜代表了不同的碳水化合物比例，以及水和蔗糖作为对照解决方案。我们发现荞麦和蔗糖喂养的雌性既有更长的寿命，又有更高的卵成熟率。三天大的用蔗糖和矢车菊花蜜喂养的雌性产生了更大的卵，这表明在光敏生物寄生虫中，卵性状可响应食物质量而具有可塑性。我们的结果强调了资源质量对关键生命历史特征之间的能源分配策略的重要性。雌性寄生虫在首都收入育种者连续体中的位置可能因其处理不同质量糖资源的能力而异，这可能会减少对资本储备对生殖功能的依赖。因此，我们建议在这些生物采用的生命史策略的未来研究中，将资源质量纳入CIBC概念框架。