Many people are inclined to shoo flies away from their food, and the idea of maggots in our trash bins can be quite repulsive.
However, some city councils have embraced maggots, also known as fly larvae, and their ability to consume rotting food.
In the capital city of Vilnius, Lithuania, fly larvae have been officially tasked with processing the 2,700 tonnes of food waste produced by the city’s 607,000 residents each year. This initiative also extends to six neighboring councils.
The waste management company, Energesman, which began handling Vilnius’ food waste earlier this year, does not charge the city for this service. According to the company’s CEO, Algirda Blazgys, this is estimated to save the city up to €2m (£1.7m; $2.3m) annually, based on a target of processing 12,000 tonnes by 2026.
Energesman has introduced new orange food waste bags to residents and launched an influencer marketing campaign to encourage more Vilniečiai to separate their food waste. However, the 2,700 tonnes collected is only a fraction of the estimated 40,000 tonnes of household waste generated by the city.
Since it became mandatory for councils to collect food waste, the city is in need of effective ways to manage it. Energesman has plans to turn the fattened fly larvae into a new source of income.
The company currently houses around six million flies in a designated area within its Vilnius plant. These flies mate every six hours, and a female fly can lay up to 500 eggs in her average lifespan of 21 days. This means that Mr. Blazgys and his team are dealing with over three million larvae each month, which can consume more than 11 tonnes of food waste in the first few days of their lives.
Their voracious appetites make fly larvae ideal candidates for food waste processing. In a study, a swarm of them was able to consume a 16-inch pizza in just two hours.
The key is to harvest them before they mature into flies. This way, the protein-rich larvae can be converted into protein products for animal feed or industrial use, such as in paint, glue, lamp shades, and furniture covers.
Their manure, also known as frass, can also be used as fertilizer.
Energesman has already established supply trials with partners in the paint, glue, and furniture industries. However, Mr. Blazgys admits that it has been more challenging than anticipated.
The sample paint produced using Energesman-reared fly larvae did not turn out in the desired color, but the lamp shades created showed promise.
The company also has partnerships with universities to supply fly larvae for research purposes and to feed bacteria. Additionally, the local fishing industry is interested in using the larvae as bait.
However, EU health and safety regulations prevent fly larvae fed with kitchen waste from being used in edible insect products for human consumption due to the risk of cross-contamination from meat and fish scraps.
"We came up with some crazy ideas, and then we started looking for other people who could also come up with some crazy ideas about what we could do," says Mr. Blazgys.
"Since it’s still relatively new, some people are still waiting to see if we will fail, so they are not yet willing to promote it. But I believe we will come up with something good."
While there are many cases around the world of fly larvae being used in food waste management and harvested as a protein ingredient, it is mostly done on a commercial basis, such as through private contracts between hotels or apartment building owners and fly larvae producers.
In Kenya, Project Mila is a social enterprise that uses fly larvae to address Mombasa’s growing food waste problem while supplying frass as fertilizer to local farmers.
However, only a few city councils have adopted this method of food waste processing.
In Australia, Goterra has used fly larvae to help Sydney manage its food waste as part of a limited trial that began this year. For the past three years, Goterra has also worked with three townships in the neighboring Queanbeyan-Palerang Regional Council, recycling approximately 10 tonnes of food waste.
It is only a matter of time before UK councils start using millions of flies to process the 6.4 million tonnes of household food waste produced in the country each year, according to Larry Kotch, CEO and co-founder of insect waste management company Flybox. The company operates more insect waste processing sites in the UK than any other company and primarily works with private food manufacturers and supermarkets. Flybox is also a founding member of the Insect Bioconversion Association, an industry body that represents companies in this field.
Mr. Kotch believes that UK councils are interested, especially since weekly household food waste collections will become mandatory in England starting in March 2026. According to the Local Authority Recycling Advisory Committee, about 148 of England’s 317 local authorities still do not offer this service.
However, current regulations set by the Department for Environment, Food and Rural Affairs (DEFRA) prohibit councils from using fly larvae to process food waste.
If regulations were to align with scientific advancements, Mr. Kotch argues that "the UK could see its first council-contracted insect plant within two years."
"Unfortunately, it is always safer for the government to say no… Everyone we have spoken to in UK councils is very excited about insect protein and would prefer to work with insect farms rather than alternative technologies," he adds.
The BBC confirmed that the Animal By-Product Regulations currently prohibit the use of insects to process organic waste streams. DEFRA stated that there are no plans to review these regulations. A spokesperson said, "Our waste management regulations play a crucial role in protecting UK biosecurity and reducing the risk of disease."
The current alternative to sending food waste to landfills is anaerobic digestion (AD), a process that produces biogas. However, Mr. Kotch argues that current AD plants are not sufficient to handle the expected increase in household food waste.
"Globally, over 1.3 billion tonnes of food is wasted each year. We believe that up to 40% of that could be upcycled using insect waste management. Not only does this avoid disposal costs and methane emissions, but it also produces valuable protein and organic fertilizer," he says.