Data from: The geometric framework for nutrition reveals interactions between protein and carbohydrate during larval growth in honey bees

In holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diets are often complex and may interact with one another, necessitating the use of a geometric framework for elucidating nutritional effects. In the honey bee, Apis mellifera, nurse bees provision food to developing larvae, directly moderating growth rates and caste development. However, the eusocial nature of honey bees makes nutritional studies challenging, because diet components cannot be systematically manipulated in the hive. Using in vitro rearing, we investigated the roles and interactions between carbohydrate and protein content on larval survival, growth, and development in A. mellifera. We applied a geometric framework to determine how these two nutritional components interact across nine artificial diets. Honey bees successfully completed larval development under a wide range of protein and carbohydrate contents, with the medium protein (∼5%) diet having the highest survival. Protein and carbohydrate both had significant and non-linear effects on growth rate, with the highest growth rates observed on a medium-protein, low-carbohydrate diet. Diet composition did not have a statistically significant effect on development time. These results confirm previous findings that protein and carbohydrate content affect the growth of A. mellifera larvae. However, this study identified an interaction between carbohydrate and protein content that indicates a low-protein, high-carb diet has a negative effect on larval growth and survival. These results imply that worker recruitment in the hive would decline under low protein conditions, even when nectar abundance or honey stores are sufficient.

全变态昆虫（holometabolous insects）中，幼虫营养状况会影响成虫体型——这是一类对生存表现与适合度具有深远影响的生活史特征。幼虫日粮的各营养组分往往较为复杂且可能相互作用，因此需要借助几何框架（geometric framework）来阐明营养效应的作用机制。在西方蜜蜂（Apis mellifera）中，保育蜂会为发育中的幼虫提供食物，直接调控幼虫的生长速率与级型分化。然而，蜜蜂的真社会性（eusocial）特性使得营养研究极具挑战：无法在蜂箱内系统性地操控日粮组分。本研究利用体外饲养（in vitro rearing）技术，探究了西方蜜蜂幼虫日粮中碳水化合物与蛋白质含量对幼虫存活、生长与发育的作用及其相互作用。我们采用几何框架，分析了9种人工日粮下这两种营养组分的互作模式。结果显示，西方蜜蜂可在较宽的蛋白质与碳水化合物浓度范围内完成幼虫发育，其中中等蛋白质含量（约5%）的日粮存活率最高。蛋白质与碳水化合物均对生长速率产生显著且非线性的影响，中等蛋白质、低碳水化合物的日粮可使幼虫生长速率达到峰值。日粮组成对幼虫发育时长无统计学显著性影响。本研究结果验证了此前的结论：蛋白质与碳水化合物含量会影响西方蜜蜂幼虫的生长。但本研究同时揭示了二者的互作效应：低蛋白质、高碳水化合物的日粮会对幼虫生长与存活产生负面影响。该结果表明，即便花蜜储量充足或蜂蜜储备充裕，蜂群在蛋白质匮乏条件下的工蜂招募量也会下降。