Insects are known to selectively balance their intake of protein and carbohydrate to optimize reproduction and survival. For insects who feed on decomposing fruit, fluctuations in macronutrient composition occur as fruits ripe and decomposition progresses which may challenge optimal resource allocation. Using Drosophila melanogaster, we tested the effect of macronutrient fluctuations and the variability of these fluctuations on starvation resistance and components of reproductive output; traits known to be sensitive to different protein to carbohydrate (P:C) ratios in the diet. For 8 days, flies were fed the same protein to carbohydrate (P:C) ratio (constant feeding), or fed diets with fluctuations in P:C ratio on each day; these fluctuations being regular (predictably fluctuating) or irregular (unpredictably fluctuating). The three feeding regimes yielded the same average P:C ratio across the duration of the experiment. We found no difference in starvation resistance across the feeding regimes. Interestingly, there was a sexual dimorphism in the effect on reproductive output with males performing worst in the unpredictable feeding regime, and with no effect of feeding regime on female performance. Our study provides evidence for means of adapting to fluctuating macronutrient composition and suggests females are more tactful than males in storing and allocating resources for reproduction.

中文翻译：

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营养成分的波动会影响果蝇的雄性生殖产量。

众所周知，昆虫可以选择性地平衡蛋白质和碳水化合物的摄入，以优化繁殖和生存。对于以分解水果为食的昆虫，随着水果的成熟和分解的进行，大量营养素组成会发生波动，这可能会挑战最佳的资源分配。我们使用果蝇（Drosophila melanogaster）测试了常量营养素波动以及这些波动对饥饿抵抗力和生殖输出成分的影响。已知对饮食中不同蛋白质与碳水化合物（P：C）比例敏感的性状。连续8天，用相同的蛋白质与碳水化合物（P：C）比例喂食苍蝇（恒定喂食），或者每天摄食P：C比例波动的饮食；这些波动是有规律的（可预测的波动）或无规律的（不可预测的波动）。在整个实验过程中，三种喂养方式均产生相同的平均P：C比。我们发现在不同的喂养方式下，饥饿抵抗力没有差异。有趣的是，对生殖输出的影响存在性二态性，其中雄性在不可预测的喂养方式下表现最差，而喂养方式对雌性表现没有影响。我们的研究提供了适应不断变化的丰富营养成分的手段的证据，并建议女性在储存和分配生殖资源方面比男性更机智。雄性在不可预测的喂养方式下表现最差，而喂养方式对雌性的表现则没有影响，对生殖输出的影响存在性二态性。我们的研究为适应不断变化的丰富营养成分提供了依据，并表明女性在储存和分配生殖资源方面比男性更机智。雄性在不可预测的喂养方式下表现最差，而喂养方式对雌性的表现则没有影响。我们的研究提供了适应不断变化的丰富营养成分的手段的证据，并建议女性在储存和分配生殖资源方面比男性更机智。