Larval Performance of Black Soldier Fly (Hermetia illucens) on Fermented Corn Cob and Rice Straw Supplemented with Effective Microorganisms

Corn cob and rice straw are abundant waste products from two major food crops worldwide. Bioconversion is an opportunity to valorize these two wastes by involving Black Soldier Fly (BSF). This study aimed to evaluate BSF larval performance in corn cob and rice straw pretreated by fermentation using effective microorganisms. The experiment included four treatments: fermented corn cob (FC), non-fermented corn cob (NFC), fermented rice straw (FR), and non-fermented rice straw (NFR). Each was replicated three times and observed over three weeks. The parameters measured included larval weight, substrate consumption (SC), efficiency conversion of digested food (ECD), waste reduction index (WRI), percentage of pupae and imago, and larval proximate analysis. The results showed a decrease in larval biomass during the observation period. In the final week, the highest larval biomass, SC, and WRI were observed in NFR, with 0.18 ± 0.03 g, 14.19 ± 2.97% and 1.90 ± 0.37%, respectively. The highest ECD and percentage of transformation of pupae and imago were found in FR, with 1.84 ± 0.44%, 18.50% and 12.50%, respectively. The proximate analysis revealed that the larvae from all treatments had ideal protein levels ranging from 58% to 63%. The current study suggests that both corn cob and rice straw are feasible substrates for BSF larvae. Still, no significant difference in larval performance was found between fermented and non-fermented versions of these substrates. Optimizing the substrate treatment is necessary to improve larval performance and bioconversion outcomes