Growth performance and nutritional composition of black soldier fly (Hermetia illucens) larvae reared on various plant by-product substrates

Abstract

This study evaluated the effects of soybean residue, vegetable blend, watermelon by-product, and their mixtures on the nutritional composition, growth performance, survival, and productivity of black soldier fly larvae under practical wet-weight feeding conditions. Six-day-old larvae (50 g biomass per tray) were reared for 7 days and provided with 500 g of wet substrate daily. Substrate protein and lipid contents differed significantly among treatments (P ≤ 0.05), with soybean residue and soybean-based mixtures exhibiting the highest nutritional values. Larvae reared on soybean residue exhibited the highest protein and lipid contents, growth performance, survival, and productivity (P ≤ 0.05). In contrast, watermelon by-products resulted in the poorest growth performance and survival, although larvae fed this substrate exhibited relatively high lipid accumulation. Substrate mixtures containing soybean residue significantly improved larval performance compared with the vegetable blend or watermelon by-product alone (P ≤ 0.05), whereas the vegetable blend and watermelon by-product mixture showed limited improvement. The results indicate that soybean residue supported the highest larval performance under wet-weight feeding conditions.