Comparative performance of black soldier fly (Hermetia illucens) larvae reared on standard laboratory diets

Abstract

Black soldier fly (BSF) (Hermetia illucens) is one of the most industrially relevant insect species worldwide. Although the Gainesville diet and food waste are commonly used as laboratory diets, these diets are nutritionally imbalanced because of their entirely plant-based composition and high nutrient content variability, which limits their suitability for standardised research. In this study, dog, calf, and poultry feeds were evaluated as alternative laboratory diets and compared with conventional feeds, including the Gainesville diet and food waste. Dog and poultry feeds produced higher larval weight (0.23~0.26 g) and total larval biomass (42~50 g) than the Gainesville diet (0.10 g; 19 g), whereas food waste achieved the highest substrate reduction rate (approximately 92%) and bioconversion efficiency (approximately 28%). In contrast, the high crude fibre content of calf feed reduced the larval growth rate, diet reduction rate (approximately 47%), and BCE (approximately 12%) compared with dog or poultry feed. The Gainesville diet yielded the lowest larval performance, confirming its limited suitability as a standard reference feed. Overall, dog and poultry feeds, particularly dog feed, demonstrated stable nutritional quality and consistent rearing performance, suggesting their potential as practical and reproducible reference diets for BSF research. These findings provide a foundation for the standardization of laboratory rearing protocols, thereby enhancing the reliability and comparability of future BSF studies.