Performance and body composition of insect larvae depend on quality and quantity of their diet, and on biotic factors such as larval density. We investigated the effect of dietary nutrient concentration and larval rearing density on survival, development, growth, and protein and fat contents of larvae of the black soldier fly (BSF), Hermetia illucens L. (Diptera: Stratiomyidae). Neonate larvae were fed with a low (NC1), intermediate (NC2), or high nutrient concentration (NC3), and with four rearing densities (50, 100, 200, or 400 larvae per container). Two feeding regimes (FR) were tested: in FR1, the amount of diet added during the experiment was based on the visually estimated larval mass present, whereas in FR2, a fixed feeding ration of 0.6 g of food per larva was applied at the start. FR1 resulted in food limitation, resulting in significantly lower body crude protein content on diet NC1 than on NC2 at larval densities 100 and 200. Larval crude fat content was higher on diets with higher nutrient concentration and at lower larval densities. For FR2, development time was shorter on diets with higher nutrient concentration and at lower larval densities. Individual larval weight and total larval yield increased with higher nutrient concentration at all four larval densities. At lower nutrient concentration, higher larval density resulted in higher individual larval weight and total larval yield, revealing an interaction between larval density and dietary quality. Larval crude protein content was higher at lower densities and lower nutrient concentration. Larval crude fat was higher at higher larval densities and nutrient concentrations. This study indicates that larval protein content is regulated within narrow limits, whereas larval crude fat content is strongly affected by nutrient concentration and by larval density.

中文翻译：

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幼虫密度和日粮营养浓度对黑水虻幼虫（Hermetia illucens）性能、身体蛋白质和脂肪含量的影响

昆虫幼虫的性能和身体成分取决于其饮食的质量和数量，以及幼虫密度等生物因素。我们研究了日粮营养浓度和幼虫饲养密度对黑水虻 (BSF) Hermetia illucens L.（双翅目：Stratiomyidae）幼虫的存活、发育、生长以及蛋白质和脂肪含量的影响。用低 (NC1)、中 (NC2) 或高营养浓度 (NC3) 以及四种饲养密度（每个容器 50、100、200 或 400 只幼虫）喂养新生幼虫。测试了两种饲喂方案 (FR)：在 FR1 中，实验期间添加的饲料量基于目视估计的幼虫质量，而在 FR2 中，在开始时采用固定饲喂量，每只幼虫 0.6 克食物. FR1导致食物限制，导致在幼虫密度为 100 和 200 时，日粮 NC1 的身体粗蛋白含量显着低于 NC2。幼虫粗脂肪含量在营养浓度较高和幼虫密度较低的日粮中较高。对于 FR2，营养浓度较高和幼虫密度较低的日粮的发育时间较短。在所有四种幼虫密度下，个体幼虫重量和总幼虫产量随着营养浓度的升高而增加。在较低的营养浓度下，较高的幼虫密度导致较高的个体幼虫体重和总幼虫产量，揭示了幼虫密度和饲料质量之间的相互作用。幼虫粗蛋白含量在较低密度和较低营养浓度下较高。幼虫密度和营养浓度越高，幼虫粗脂肪越高。