Science Matters – From trash to cash

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Ever heard of black soldier flies?

No? Nor had I until I read they are a panacea for just about everything*. This is according to Entocycle, Europe’s first automated insect farm, set up in 2015 with the aim of defending and restoring the natural world.

This rather grandiose claim comes from founder Keiran Whitaker, who suggests the super-bug will cut food waste, reduce rain forest destruction and over-exploitation of oceans, while lowering carbon emissions.


‘Frass’ produced from black soldier fly larvae, a homogenous mixture of recycled organic substrate, exoskeletons and larvae castings. Photograph: Entocycle

How is this possible?

Key to these claims are black soldier fly larvae, the eating phase of its life cycle. The
maggots thrive on any organic material we throw away – that is ^33 per cent of all food products.

Presently Entocycle uses waste from a local microbrewery and coffee shops. Once fattened up, ^33 per cent of a larva’s body weight is fat and ^40 per cent is protein, all produced cheaply, sustainably and emitting less CO2 than composting the waste.

The protein and fat can then be processed into animal food. This reduces destruction of
forests to grow soya beans, 80 per cent of which go to animal feed. Additionally, it saves ocean biodiversity since ^25 per cent by weight of worldwide fish catches goes to fishmeal.

But Entocycle also aims to produce food for direct human consumption. Dried larvae are eaten in some countries, apparently tasting like peanuts. Not to everyone’s fancy I suspect, but the abundant larval fats and proteins can also be processed into foods as varied as bread and ice cream. So what are the down-sides to this project?

One is that black soldier flies are not indigenous to the UK, so escapees might upset the
balance of local wildlife. However, the adult fly does not eat so cannot prey on other insects or spread diseases. In fact, they would likely die rapidly in the wild. Another hitch involves regulations regarding feeding insect products to animals for human consumption.

Nevertheless, the EU approved their use in fish farms in 2017 and is soon expected to allow them for pigs and chickens providing the larvae are fed no meat. So we can expect
commercialisation of this revolutionary foodstuff very soon.

* D Adams. New Scientist July 17 2019.