Bioconversion of Rice straw waste by black soldier fly larvae (Hermetia illucens L.) : Optimal feed rate for biomass production

Abstract

This study focuses on the application of black soldier fly larvae (Hermetia illucens L.) as a bioconversion agent of the rice straw to reduce amount of waste while in the same time produced larvae biomass. In this study, larvae were fed with rice straw at six different feed rates (12.5, 25, 50, 100, and 200 mg/larvae/day) until larvae reached prepupal stage. During study, relative growth, relative consumption rate, and waste reduction level were measured. Daily feeding of 200 mg of grinded rice straw per larvae resulted in the highest prepupal dry weight (15.59 ± 0.01 mg), lowest developmental time (39 ± 0.1 days), but lowest waste reduction efficiency (10.85 ± 0.0005%). Highest waste reduction efficiency was recorded by larvae feed rate of 12.5 mg/larvae/day (31.53 ± 0.01%) and decreased with higher feeding rate. This study showed the possibility of production of insect larvae biomass as through bioconversion process of agricultural waste rich with lignocellulose.