The role of the growing substrate

The growth and nutritional composition of black soldier fly larvae (BSFL, Hermetia illucens) are highly influenced by the quality and type of rearing substrate. Substrate variability plays a pivotal role in determining larval protein, lipid, and mineral content, making BSFL a dynamic resource for sustainable food and feed production. High-protein substrates typically enhance larval protein content, while carbohydrate-rich or lipid-dense substrates influence fatty acid profiles, including lauric acid and omega-3 concentrations. Beyond macronutrient composition, substrates also affect the accumulation of micronutrients and bioactive compounds like chitin. The microbial composition and quality of substrates impact larval growth performance, feed conversion efficiency, and waste reduction capabilities. By leveraging diverse organic waste streams, BSFL farming aligns with circular economy principles, providing a dual solution for waste management and the production of nutrient-rich biomass. This chapter explores the intricate relationship between substrate composition and BSFL nutritional outcomes, highlighting its relevance to sustainable agricultural systems.