Optimization of Black Soldier Fly (Hermetia illucens) production for organic waste management in a small-scale institutional facility (Nairobi)

Safe management of faecal waste is especially challenging in resource-constrained countries. This has led to unregulated faecal waste management posing a great risk to human health and the environment. One of the solutions to poor management of organic waste is to create value from waste. One way to do this is the use of black soldier fly larvae (BSFL) bioconversion technology. The study, assessed the optimization of black soldier production at the post-feeding stages of adult emergence and oviposition. Using different feed substrates, five-day-old larvae were introduced into containers, and growth was monitored until post feeding stage. The feed substrates used were faecal matter, kitchen waste, and a mixture of kitchen waste and faecal matter at a ratio of 1.1. Plastic grooved pipes of different colours were placed in a container with an attractant for BSF to lay eggs whose weight was then taken. Space requirement was determined by placing post-feeding larvae in cages of different dimensions.  Performance was measured by the number of adults that emerged and the weight of eggs. Study results showed that the black-coloured ovipositing structure was most preferred for ovipositing while yellow was the least preferred. Cages of 2.5 and 2m performed better in terms of egg production and adult emergence. Co-treatment of faecal matter and kitchen waste resulted in a better substrate for adult emergence and egg production. The study shows the way for effective rearing of BSF for on-site facilities faecal matter management, managing other organic wastes, and providing alternative animal feed and organic fertilizers for soil conditioning.