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/m 2 (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.

Feeding strategies for small-scale rearing black soldier fly larvae (Hermetia illucens) as organic waste recycler

“…CF, chicken feed; CM, chicken manure; FW, fruit waste The larvae fed in continuous feeding diets tended to develop fast into large pre-pupae compared to those subjected to the batch feeding diets. Similar results were observed by Nana et al [32], who argued that BSF larvae have preference for fresh diet as compared with rotten diet. Other authors also demonstrate that most organic wastes lose their nutritional value over time due to the action of microorganisms [31,44].…”

“…It is important to note that these values were calculated based on the dry weight of the different substrates. The bioconversion rates calculated based on the wet weights are much lesser than the values obtained in this study, due to the influence of the water content of the substrates [32,47].…”

“…Black Soldier Fly offers a promising solution to improve the collection and recycling of organic waste, which is actually responsible for many unsanitary problems encountered in urban areas. During their larval stage, the BSF feeds voraciously on various types of organic waste and converts carbohydrates and nitrogen compounds into secondary protein products [32,36,37].…”

“…Various studies have investigated into the effects of different organic waste streams on laboratory-reared BSF [28][29][30], as well as the influence of animal manure or food waste on the development and survival of BSF larvae using experimental prepared diets [8,28]. Other studies have investigated the potential of BSF larvae to recycle these organic wastes into useful products [31][32][33]. However, most of these studies focus on the waste stream-based diets and lack information on the effects of feeding strategy.…”

Agricultural value of Black Soldier Fly larvae frass as organic fertilizer on ryegrass

“…The composition of the BSFF, produced with different substrates, is different and there is a need to investigate how it can affect crops yield (Kagata and Ohgushi, 2012;Salomone et al, 2017;Gold et al, 2018;Nana et al, 2018).…”