Bioconversion performances of black soldier fly larvae (hermetia illucens l. diptera: stratiomyidae) on selected organic substrates

Abstract

Black Soldier Fly Larvae (BSFL; Hermetia illucens L.) is a bioconversion agent of organic substrates and its proven ability to degrade and biotransform of waste strengthens organic waste management and waste recycling strategies. BSFL have the advantages of rapid development and very efficient conversion of various organic wastes into body biomass. This process reduces the disposal costs of organic waste as well as the use of energy providing a sustainable solution to the treatment of organic waste. In addition, it provides valuable products and fertilizers for agriculture, potentially reducing crop production costs for farmers. The current study investigated the potential live biomass production of BSFL using different organic substrates available locally while understanding their decomposition ability. Seven treatments were compared (T1- equal proportion of poultry manure and rice bran, T2- equal proportion of goat manure and rice bran, T3- rabbit droppings, T4- soybean meal, T5- coconut scrapings, T6- equal proportion of vegetable and fruit waste and T7- cow dung) and the experiment was set up as completely randomized design with three replicates. The study results examined the ability of BSFL to reduce the weight of the end-substrate and promote the degradation of organic waste materials. The live biomass production of larvae, changes in live biomass production, substrate consumption rate, the weight of the end-substrate and substrate conversion efficiency were significantly different among treatments. The greatest live biomass production of BSFL was recorded in coconut scrapings and vegetables & fruit waste mixture while the lowest value was observed in cow dung. Coconut scrapings reduced most of their weight at the end of the study indicating the highest substrate consumption rate and the total weight of the end-substrate consisted of < 2mm particle in size. However, the highest substrate conversion rate was observed in cow dung. Aqueous solutions prepared from the end-substrates varied widely in pH, electrical conductivity, total dissolved solids, and salinity. In addition, significant differences were found among treatments for the colour and texture of the end-substrate. However, the appearance and odour did not differ significantly. According to the results of the present study, it can be concluded that the most efficient media for BSFL was coconut scraping though; it cannot be used as organic fertilizer as it exceeded the pH value of the SLS recommendation for compost. Overall, BSFL can be recognized as an effective and environmentally friendly tool to use in the biotransformation process of locally available organic waste materials