Research on the black soldier fly is attracting growing interest globally due to the ability of its larvae to bio-remediate waste and other substances (inorganic and organic) with potential impacts on environmental safety and health.
Below, a brief review of the uses of these insects and their by-products now permitted in the EU, and their prospects for use. In agriculture and livestock farming, as well as in other production sectors, according to the paradigm of the circular economy.
1) Black soldier fly, a universal bioconverter
Hermetia illucens L., the black soldier fly, is an insect of the order Diptera (like the common fly). And it stands out from other insects for its extraordinary ability to convert waste and refuse, with extraordinary conversion rates – up to 85%, as seen (1) – into biomass with high added value (oil, proteins, chitin), which is added to the production of frass.
The breeding of ‘black soldier fly larvae’ (BSFL) thus allows the transformation of materials otherwise destined for energy recovery or disposal as waste – such as waste from fishing and the fishing industry, in the EU research project EcoeFISHent (2) – into raw materials for agro-food production (i.e. fertilisers, feed and novel foods) and for pharmaceuticals, cosmetics, packaging and biofuels.
2) Insects. Authorized uses in the EU
Animal By-Products Regulation (EC) 1069/2009, ABPs, classifies products obtained from insects as ‘processed animal proteins’ (PAPs), when they are not ‘novel foods’. Regulation (EU) 142/2011, currently the ABPs, defines the methods of use, the intended uses (which include other products, such as oil) and the restrictions (i.e. cannibalism).
TSE Regulation (EC) 999/01 then introduces further restrictions on the use of animal proteins as raw materials for feed intended for certain animal species (feed ban), with particular regard to ruminants, in order to avoid the risk of the onset of diseases caused by prions (infectious glycoproteins) such as Creutzfeldt-Jakob disease (or BSE). In this regard, it is noted that:
– restrictions for the control of TSEs do not apply to non-food uses (e.g. cosmetics, medicines) nor to other products subject to specific and accurate risk assessment (i.e. Novel foods);
– black soldier fly PAPs can be administered in aquaculture, poultry and pig farming, thanks to the derogations introduced by the Commission following EFSA evaluations. (3)
3) Live insects in livestock farming
The use of live insects in animal feed of all types – including pets, fur animals or other animals covered by the ABPs Regulation (e.g. circus animals, reptiles) – has been the subject of evaluations and debates by the competent authorities of several EU Member States.
PAFF (Plant, Animals, Food and Feed) Standing Committee, in February 2024, finally recognized that:
– live insects are not classified as animal by-products;
– their use is permitted, in compliance with the requirements set out in Feed Regulation (EC) 767/2009 on feed;
– the feed ban still applies to ruminant nutrition, since live insects contain proteins. (4)
Feed Materials Catalog Regulation (EU) 68/2013, moreover, had already paved the way for a wide use of live insects and their carcasses. PAPs and insect oils in animal feed.
4) Black soldier fly in livestock and agriculture
A systematic scientific review (Siddiqui et al., 2024) identifies the applications of greatest interest for the black soldier fly, compared with conventional products already commercially available. (5)
4.1) Raw materials for feed
The costs of conventional proteins (i.e. soy, fish) for feed production are increasingly high, due to a variety of factors that include, in Europe, the surge in energy bills. Land consumption for the cultivation of raw materials for feed, rather than food, is moreover one of the first accusations against the livestock supply chains.
Black soldier fly larvae (live or processed) can be fed to fish, poultry and pigs with significant cost savings and without compromising the quality of their meat. Animal health and welfare may even benefit from some of the antimicrobial properties of BSFL, such as the inhibition of Clostridium perfrigens which can cause diarrhea in dogs, cats and pigs.
4.2) Fertilizers
The frass – animal by-product obtained from insects – is one of the most promising organic fertilizers, whose use has been permitted in the EU for several years. It has a higher organic substance content than manure, and is able to contribute both macroelements such as phosphorus and potassium, and microelements (e.g. calcium, magnesium, copper, iron). Its composition and physical structure also make it easier to spread and absorb by various crops (e.g. corn), with higher yields than urea and other commercial products.
The characteristics of frass, like those of the larvae, are also linked to the feeding of BSFL. And therefore a specific evaluation is appropriate, to determine their composition and evaluate their use for the different crops. An excessive use could lead to toxicity, due to the presence of ammonia and sodium; therefore, their combination with inorganic fertilizers (in a 10-40% quota) is recommended, so as to balance the yields with a biostimulating effect of resistance to diseases and pathogens. The chitin present in frass has an antimicrobial action against pathogenic microorganisms and promotes the development of those useful to the rhizosphere microbiome.
5) Food waste valorization
The growing interest for the black soldier fly is also due to its ability to valorise food waste and refuse, which express an unsustainable waste of resources and at the same time an environmental problem and are therefore at the centre of several EU research projects (ie #Wasteless). Pre-treatments of such materials can favour their conversion, improving the microbiota and the bioremediation activity of these insects (6,7).
The restrictions introduced by the ABPs regulation still prevent the use of kitchen waste and unprocessed meat and fish scraps, in the EU, for larval nutrition. Instead, other products such as fruit and vegetables, dairy products and food industry waste can be used. The various nutrients do not create particular problems, with the exception of some polyphenols that can limit the growth of adult larvae. Which are also able to digest microplastics well.
The environmental assessment and economic benefits associated with the treatment of food waste and the production of larvae demonstrate a good capacity to reduce environmental impacts, with interesting economic returns from the various products obtained from the larvae.
6) Provisional conclusions
The black soldier fly is confirmed as the biodigester par excellence, with promising prerogatives in terms of circular economy. The optimal use of this insect in the context of the circular economy still requires, however, significant investments in terms of research and industrial application.
European legislation should also be updated to allow the safe use – in insect farming – of materials classified as ABPs and still subject to restrictions that may not be proportionate to the objectives.
Dario Dongo and Andrea Adelmo Della Penna
Credit cover M., Pushpalatha & Gadge, Ankush & Bankar, Devanand. (2023). Treasure out of trash -black soldier fly. Insect environment 25. 58- 66. 10.55278/QFAB1574 https://tinyurl.com/yryuxnrk
Footnotes
(1) Andrea Adelmo Della Penna, Dario Dongo. Black soldier fly larvae, proteins and oils from organic waste. FT (FoodTimes). April 11, 2022
(2) Dario Dongo, Andrea Adelmo Della Penna. EcoeFISHent, upcycling and blue economy in the fish supply chain. The EU research project. GIFT (Great Italian Food Trade).
(3) Animal by-products other than PAPs (i.e. insect oil) do not fall under the feed ban, provided that the absence of animal proteins in them is guaranteed.
(4) Standing Committee on Plants, Animals, Food and Feed, Section Animal Nutrition. 15-16.2.24 https://tinyurl.com/y3nhr2v5
(5) Siddiqui et al. (2024). Future opportunities for products derived from black soldier fly (BSF) treatment as animal feed and fertilizer – A systematic review. Environment, Development and Sustainability 26: 30273-20354, https://doi.org/10.1007/s10668-024-04673-8
(6) Ganesan et al. (2024). Food waste-derived black soldier fly (Hermetia illucens) larval resource recovery: A circular bioeconomy approach. Process Safety and Environmental Protection 184: 170-189, https://doi.org/10.1016/j.psep.2024.01.084
(7) Salam et al. (2024). Exploring the role of the microbiome of the H. illucens (black soldier fly) for microbial synergy in optimizing black soldier fly rearing and subsequent applications. Environmental pollution 363: 125055, https://doi.org/10.1016/j.envpol.2024.125055
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in Food Technologies and Biotechnologies, qualified food technologist, he follows the research and development area. With particular regard to European research projects (in Horizon 2020, PRIMA) where the FARE division of WIISE Srl, a benefit company, participates.
