Valorisation of organic waste material: growth performance of wild black soldier fly larvae (Hermetia illucens) reared on different organic wastes

Abstract

Insects such as the black soldier fly (BSF; Hermetia illucens) are currently being promoted as an alternative protein source for animals and organic waste management agents. To play the dual roles sustainably, there is need to reduce reliance on wild BSF and develop an appropriate farming methodology for the insect. This study aimed at improving larvae production in a black soldier fly colony previously established from the wild in Kenya. The study explored the effect of four locally available organic wastes as feedstocks for production the black soldier fly larvae. Separate feeding trials on faecal sludge (FS), banana peelings (BP), brewer’s waste (BW) and restaurant food waste (FR) was done and their effect on BSF larvae growth rate, larvae weight, total prepupal yield in grams, crude protein and lipid (ether extract) content analysed. The efficiency of the BSF larvae to consume and therefore reduce the waste load of the different substrates was also evaluated. Results showed that BSF larvae fed on FR had significantly higher (P<0.05) total mean yield and average individual weight of 196.9±4.0 g and 0.101±0.002 g, respectively, followed by BW (154.8±6.5 g, 0.078±0.02 g), FS (138.7±5.0 g, 0.070±0.001 g) and with BP the lowest (108.9±5.6 g, 0.055±0.002 g). The harvested BSF larvae crude protein was significantly higher for FS and BW at 45.4±0.1% and 43.0±1.0%, respectively. However, ether extract content was variable and dependent on feedstock used with lower values reported for FS and BW (18.1±0.3% and 27.2%, respectively), and highest for food remains prepupa (36%). Dry matter reduction ranged between 50.3-81.8% with corresponding bioconversion and feed conversion rates ranging from 14.9-20.8% and 2.6-4.5, respectively, was achieved for the substrates used. These results indicated the potential of utilising BSF composting in valorisation of the local organic wastes for their bioremediation from the environment. Due to their availability in large quantities and their low cost, these organic wastes can form important feedstock resources for the sustainable production of BSF larvae as a future alternative protein source for both animal feeds at farm level and industrial scale. In conclusion, embracing nutrient recycling through BSF technology by resource-constrained farmers in Kenya will contribute to food security through supply of proteins for production of poultry and fish.

Reducing the Space Footprint of Black Soldier Fly Larvae Waste Treatment by Increasing Waste Feeding Layer Thickness

“…At 90 cm WLT, lowest dry weight reduction was achieved which differed significantly from control 10cm and all other samples (Table 2). Material reduction achieved in the present study was higher than mentioned for fruit and vegetable waste, banana peelings, food waste, pig manure, dog food, dairy manure, fecal sludge, and brewer's waste [20,21,[23][24][25][26]. This might be due to regular mixing (on daily basis) of waste and larvae in order to allow air circulation and equal distribution of BSFL in waste sample, which if not done may lead to their accumulation in colonies and corners depriving many of food.…”

Nutrient Recapture from Insect Farm Waste: Bioconversion with Hermetia illucens (L.) (Diptera: Stratiomyidae)

“…Cricket waste and the control diet showed the highest percentage in mass reduction, and data were similar to municipal waste [59] or on dairy manure and soybean curd residue [26]. Furthermore, Nyakeri et al (2017) [60] found a substrate reduction from 44 to 81% on different organic waste substrates. The high value on cricket waste suggests the possibility of using H. illucens larvae to reduce the amount of such waste produced during the cricket rearing.…”

Hydrolytic Profile of the Culturable Gut Bacterial Community Associated With Hermetia illucens

“…population loads in manures (Liu et al, 2008;Lalander et al, 2015), probably due to the abundance of different antimicrobial peptides (AMPs) that it can produce (Vogel et al, 2018). Since it has been estimated that the food wastage (a term that includes both food waste and food lost) accounts approximately for one third of all the food produced for human consumption (FAO, 2013), BSF could be used for organic waste reduction and valorization, converting it into biomass with a final added value as feed, food or fuel (van Huis, 2013;Nyakeri et al, 2017;Chia et al, 2018;Onsongo et al, 2018;Shumo et al, 2018;Cappellozza et al, 2019). Under this perspective and considering the increasing exploitation of H. illucens for bio-waste disposal and its conversion in animal feed, elimination of toxic and antinutritional compounds (i.e., that can reduce the availability of nutrients such as phytate) present in the insect diet source could be also an important aspect to take into account in order to improve the insect growth.…”