Data from: Macronutrient intake regulates sexual conflict in decorated crickets

Sexual conflict results in a diversity of sex-specific adaptations, including chemical additions to ejaculates. Male decorated crickets (Gryllodes sigillatus) produce a gelatinous nuptial gift (the spermatophylax) that varies in size and free amino acid composition, which influences a female’s willingness to fully consume this gift. Complete consumption of this gift maximises sperm transfer through increased retention of the sperm-containing ampulla, but hinders post-copulatory mate choice. Here, we examine the effects of protein (P) and carbohydrate (C) intake on the weight and amino acid composition of the spermatophylax that describes its gustatory appeal to the female, as well as the ability of this gift to regulate sexual conflict via ampulla attachment time. Nutrient intake had similar effects on the expression of these traits with each maximised at a high intake of nutrients with a P:C ratio of 1:1.3. Under dietary choice, males actively regulated their nutrient intake but this regulation did not coincide with the peak of the nutritional landscape for any trait. Our results therefore demonstrate that a balanced intake of nutrients is central to regulating sexual conflict in G. sigillatus but males are constrained from reaching the optima needed to bias the outcome of this conflict in their favour.

性冲突（sexual conflict）可催生多样的性别特异性适应策略，其中包括精液的化学修饰。雄性花斑蟋蟀（Gryllodes sigillatus）会分泌一种凝胶状婚赠胶团（spermatophylax），该胶团的大小与游离氨基酸组成存在个体差异，这会影响雌性完全吞食该胶团的意愿。完全吞食该胶团可通过提升雌性对含精子精囊（ampulla）的留存率，最大化精子传递效率，但同时会阻碍雌性的交配后配偶选择。本研究探讨了蛋白质（P）与碳水化合物（C）的摄入量对婚赠胶团重量与氨基酸组成的影响——这两项指标直接决定了该胶团对雌性的味觉吸引力，同时也分析了该胶团通过精囊附着时长调控性冲突的能力。营养摄入对上述性状的表达具有相似的调控效应：当营养摄入量较高且P:C比例为1:1.3时，各项性状均达到峰值。在可自主选择膳食的条件下，雄性会主动调控自身的营养摄入，但这种调控并未与任意一项性状的营养最优区间相匹配。综上，本研究结果表明，营养均衡摄入是花斑蟋蟀（G. sigillatus）中性冲突调控的核心机制，但雄性个体无法达到能够让该冲突结果向自身倾斜的最优营养摄入状态。