Sofia diet: cooking up a standard diet for black soldier fly research

Abstract With increasing interest in Hermetia illucens as a model organism for bioconversion, establishing standardized approaches for evaluating and comparing research outcomes is essential. Diets for black soldier fly (BSF) are often based on raw ingredients, which can vary significantly in quality, seasonality and availability, making research difficult to replicate and slowing industry development. To address this variability, we introduce the Sofia diet, an artificial, standardized diet that can be reproduced globally with consistent nutritional composition. Unlike other diets that are used in BSF research, the proposed Sofia diet is engineered to optimize BSF larva performance by following the performance on basic traits (survival and larva weight). Developed using surface mixture experiments, the diet is optimized for application during the larval stage. Hydrolyzed yeast, sucrose, and xanthan gum were identified as core ingredients in a three-step optimization process, followed by refinement of the preparation methodology. The adoption of standardized diets like the Sofia diet offers a valuable tool for enhancing research across diverse scientific disciplines, while supporting industrial efforts to develop efficient BSF rearing systems and high-value products. We also envision that standard diets like Sofia diet could be used to further study insect nutrition in this species. Further optimizations of the diet recipe are also discussed.