Black soldier flies (<i>Hermetia illucens</i> Linnaeus) as recyclers of organic waste and possible livestock feed

Abstract

Valorisation of organic waste through larval feeding activity of the Black Soldier Fly (BSF),
Hermetia illucens, constitutes a potential benefit for low- and middle-income countries. BSF larvae feed on organic waste while building their body composition of protein and fat. As a response to the escalating demand for protein in livestock feed, their protein can be used to replace fishmeal in monogastric animals’ diet. Experiments were carry out to evaluate the feasibility of Black Soldier Fly (BSF) Hermetia illucens Linnaeus larvae to digest and degrade organic waste in a small-scale. Organic wastes (pig and chicken manures and kitchen wastes) were introduced in basins with 2000 young larvae (3-5 day-old) per basin for 15 days in batch and continuous feeding. We achieved an average pre-pupae production 830.1 and 694.0 g/m2 (wet weight) under favourable conditions respectively in continuous and in batch feedings. Larvae fed every three days with waste materials developed into significantly larger larvae and pre-pupae than those fed at once. Waste reduction ranged from 53 to 80% depending on the daily amount of waste added to the experimental unit. The bioconversion rates were 12.8%, 10.7% and 6.5% respectively for chicken manure, pig manure and kitchen at the feeding ratio of 220 mg/day/larvae in continuous feeding. This study confirmed the great potential of BSF as a component of waste management in low and middle-income countries. If applied in organic waste management chain, the process could contribute to generate biofuel energy as well as sustainable protein provision to the animal industries. It could further reduce waste amounts significantly, minimizing possible pollution and improving environmental sanitation.

Keywords: Hermetia illucens, organic waste, waste reduction, bioconversion, protein