Production efficiency and nutritional potential of black soldier fly (Hermetia illucens Linnaeus, 1758) larvae with an evaluation of growth performance in Nile tilapia (Oreochromis niloticus Linnaeus, 1758).

Abstract

Objectives: This study evaluated the production efficiency, nutritional value, growth performance, and economic viability of black soldier fly (BSF) (Diptera: Stratiomyidae) larvae as a sustainable alternative to commercial feed in Nile tilapia (Oreochromis niloticus) aquaculture. Materials and Methods: BSF larvae were reared on a mixed substrate of four organic waste types. Monthly total larval yield, substrate reduction efficiency, and conversion rate were calculated to evaluate production efficiency. The nutritional composition of BSF larvae and commercial fish feed was determined through proximate analysis following the AOAC (1980) procedures. Growth performance was assessed using 30 Nile tilapia (15 fish per tank). Fish were fed daily at 5% of body weight. The control group received 100% commercial feed, whereas the experimental group received 100% BSF larvae. Results: One-way ANOVA revealed significant (p < 0.05) monthly effects on total larval yield (1.44 × 10^-7), substrate reduction efficiency (0.0002), and conversion rate (1.6 × 10^-8). LSD post-hoc analysis identified April as the peak production month. Cohen's d showed medium differences in dry matter (0.74-0.73) and moisture (0.75-0.76), very large differences in crude protein (3.26-4.08) and ash (3.11-3.32), and extremely large differences in ether extract (9.77-10.23), highlighting the superior nutritional value of BSF larvae. Weight gain did not differ significantly between feeding treatments (p > 0.05), although BSF-fed fish showed slightly greater growth. Cohen's d revealed a medium effect size, suggesting a moderate advantage of BSF larvae. Conclusions: Nile tilapia fed 100% BSF larvae achieved growth comparable to those fed commercial feed at less than half the feed cost (77.79 vs. 161 BDT/kg), demonstrating that BSF larvae are a nutritionally rich, economically viable, and sustainable protein source for aquaculture in Bangladesh.