Potential Application of Black Soldier Fly Larva Bins in Treating Food Waste

SIMPLE SUMMARY: As a converter of organic waste, the black soldier fly (BSF), Hermetia illucens Linnaeus (Diptera: Stratiomyidae), has been introduced, especially to deal with the increasing organic waste generation and the number of landfills. In this study, we designed a user-friendly BSF larvae (BSFL) bin that the public and institutions can fabricate and use as an effort to reduce waste. We also tested mixtures of food waste and moisture content control medium (MCCM) as larval feeding mediums to ease the handling and maintenance of the bins and identify the optimum medium for larval growth. Our findings show that the fabricated BSFL bins can fulfil the BSF lifecycle requirements. The medium without MCCM produced the highest larval growth; however, the high moisture content of the medium causes difficulty in handling and managing the bins. Overall, the mediums with MCCM produced lower moisture, which makes bins easier to maintain, and it is proven in this study that chicken feed is the most suitable MCCM as it produces the optimum larval growth and frass moisture. ABSTRACT: The increase in the global population has led to a rise in organic waste generation and landfill sites. Consequently, there has been a global shift in focus towards the utilization of BSFL to address these challenges. This study aims to design, develop, and test a user-friendly BSFL bin and identify the optimal MCCM for treating organic waste using BSFL. The four BSFL bins have a dimension of 330 mm (width) × 440 mm (length) × 285 mm (height). This study uses mixtures of food waste added with different MCCMs, including chicken feed, rice bran, and garden waste. We add the mediums to the BSFL bins every third day and measure the humidity, ambient temperature, pH, medium temperature, and BSFL weight and length. The measurements show that the fabricated BSFL bins can fulfill the BSF lifecycle requirements. Wild BSFs lay eggs in the medium of BSFL bins, and the hatched larvae decompose it. When they reach the prepupae stage, they climb the ramp into the harvesting container. The results show that the food waste without MCCM produced the heaviest (0.228 g) and longest (2.16 cm) larvae; the prepupae are 2.15 cm long and weigh 0.225 g; and the growth rate is 53.72%. However, the high moisture content of 75.3% makes the maintenance work challenging. The medium with MCCM has a markedly lower moisture content of 51–58%. A comparison of the three MCCMs shows that the chicken feed produces the larvae and prepupae with the highest growth rate (the larvae are 2.10 cm long and weigh 0.224 g, the prepupae are 2.11 cm long and weigh 0.221 g, and the growth rate is 72.36%) and the frass with the lowest moisture content (51.2%). An effective BSFL composting system is easy to manage and produces the biggest larvae. In summary, food waste mixed with chicken feed is the most suitable MCCM for treating organic waste using BSFL.