Conversion of organic resources by black soldier fly larvae: Legislation, efficiency and environmental impact

Abstract

To meet the projected substantial growth in the global demand for meat, we are challenged to develop additional protein-rich feed ingredients while minimizing the use of natural resources. The larvae of the black soldier fly (BSF) have the capacity to convert low-value organic resources into a high quality protein source for pigs, chickens and fish and as such may increase both the productivity and the efficiency of the food chain. The aim of this study was to assess the environmental opportunities of BSF larvae reared on different sources using up to date literature data on the efficiency of BSF larvae in converting such resources into biomass. The current EU legislative framework was used to classify the various resources for rearing insects. Data of forty articles published until 1 September 2017 were used, reporting on in total 78 (mixtures of) resources used for growing BSF larvae. Data on the resource conversion efficiency on dry matter (DM) and N basis was presented in 11 and 5 studies, evaluating 21 and 13 resources, respectively. Resources studied included food and feed materials (A, n=8 resources), foods not intended (anymore) for human consumption (B1, n=4), and residual streams such as food waste (D, n=2), and animal manure (E, n=7).Conversion efficiency varied from 1.3 to 32.8% for DM and from 7.4 to 74.8% for N. Using life cycle assessment, our environmental results showed that resources within the legal groups (i.e. A and B1) that are, at the moment, not allowed in EU as animal feed have in general a lower impact in terms of global warming potential, energy use, and land use. On a per kg protein basis, BSF larvae reared on a resource that contains food (e.g. sorghum) and feed (e.g. dried distillers grains with solubles) products generally have higher environmental impacts than conventional feed protein sources (fishmeal and soybean meal). Using insects as feed, therefore, has potential to lower the environmental impact of food production but a careful examination of the resource is needed in terms of environmental impact, safety and economics.

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

“…Hermetia illucens larvae have been suggested to have an important role to play in the framework of the circular economy by recycling resources that are normally eliminated or that do not find a reallocation in the food chain [18,43,44]. Larvae of this fly can feed on a wide range of organic substrates characterized by a different content of nutrients producing high-rich protein feed for livestock [16,31,45,46].…”

“…regulations prohibit the use of insects in the food chain if they are grown on manure or waste of animal origin. Nevertheless, many papers have shown that the environmental impact of insect production is highly influenced by the insect rearing substrate [43,44,47,48]. Thus, the possibility to exploit different waste streams could lower the environmental impact of insect mass production compared to the feed currently used (mainly feed for poultry) as well as contributing to the waste management.…”

Insects as food and feed, a new emerging agricultural sector: a review

“…Besides, it is possible to use organic side streams as feed for the insects. Bosch et al (2019) reviewed forty articles dealing with environmental impact (global warming potential, energy use, and land use) of manure, catering waste or municipal waste conversion by black soldier fly larvae. The impact was lower than that of fishmeal and soy, but not when larvae converted substrates which contained food and feed products such as sorghum and DDGS (dried distillers' grains with solubles).…”

Black soldier fly larvae as a sustainable animal feed ingredient in Kenya

“…Insects convert their feed more efficiently than pigs and cattle (Bosch et al, 2019;Dobermann et al, 2017;Halloran et al, 2018;, which contributes to their importance for valorizing organic waste streams (Chia et al, 2018b). Sustainability of insect production is highest if the insects are fed with organic resources that are currently not suitable as feed for livestock.…”

“…Current protein sources in feed are soybean meal and fishmeal whose use is under pressure because of environmental aspects (Dicke, 2018). Therefore, rearing BSF as feed may mitigate environmental impact of feed production (Bosch et al, 2019).…”