Nutritional studies often require precise control of nutrients via dilution of artificial diets with indigestible material, but such studies in bees are limited. Common diluents like cellulose typically result in total mortality of bee larvae, making quantitative studies difficult. We investigated potential alternative dietary dilution agents, sporopollenin (pollen exines) and agar. We reared Osmia bicornis larvae on pollen diluted with these substances, alongside undiluted controls. Sporopollenin neither prevented nor improved survival, suggesting it is a suitable diluent. Agar appeared marginally to increase survival and its suitability requires further research. Both substances reduced cocoon weight, and sporopollenin also prolonged development, suggesting processing costs. Determining the physiological mechanisms driving these responses requires further work. Our findings should facilitate studies involving nutritional manipulations for solitary bees.

中文翻译：

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孢粉素作为独居蜜蜂人工饲料中的稀释剂

营养研究通常需要通过用难消化的材料稀释人工饲料来精确控制营养，但这种对蜜蜂的研究是有限的。像纤维素这样的常见稀释剂通常会导致蜜蜂幼虫的总死亡率，从而使定量研究变得困难。我们研究了潜在的替代膳食稀释剂、孢粉素（花粉外壁）和琼脂。我们在用这些物质稀释的花粉上饲养 Osmia bicornis 幼虫，以及未稀释的对照。孢粉素既没有阻止也没有提高存活率，表明它是一种合适的稀释剂。琼脂对提高存活率的作用微乎其微，其适用性需要进一步研究。这两种物质都减少了茧的重量，孢粉素也延长了发育，表明加工成本。确定驱动这些反应的生理机制需要进一步的工作。我们的研究结果应该有助于对独居蜜蜂进行营养操作的研究。