This kind of "fly" can not only be caught by hand, but also eaten

If there is a kind of "fly" that is larger than ordinary flies and flies slower, so slow that it can be caught with bare hands, and they do not carry and spread germs, would you accept it?

This "fly" is called the black soldier fly (Hermetia illucens). Many farms are already breeding it, and scientists are also studying its application prospects. So what are its uses?

Have you seen it? Image source: gbif

Larvae have many uses

About one-third of the black soldier fly larvae are fat and almost half are protein. Therefore, they become the main raw material of animal feed, replacing traditional feed. This can not only effectively reduce environmental pollution, but also reduce the reclamation of land.

Larvae of soldier black flies, image source: gbif

Its larvae are also the main raw material for biofuels. Scientists extract the bio-crude oil by squeezing the fat of the larvae and mix them with standard diesel to create a new type of diesel. This mixed diesel can improve the performance of diesel engines by 20% and reduce emissions of polluting gases.

The protein in the larvae can be used as a raw material for making plastic substitutes. Scientists extract the protein from the larvae and add glycerol. The resulting mixture has good elasticity. By compressing this mixture, a hard plastic substitute is obtained, which has a wide range of applications.

The remains of larvae and adults are also very useful. Their remains are rich in a long-chain polysaccharide substance - chitosan, which is one of the raw materials for products such as toothpaste and shampoo.

The larvae of black soldier flies have a rich diet and will even eat industrial wastewater rich in heavy metals such as lead, cadmium and mercury. Therefore, they can be used to effectively treat industrial wastewater.

In addition to the above uses, larvae can also become a source of food for humans because they are rich in fat and protein, and their quality is even similar to that of common meat livestock such as cattle, sheep and pigs in our daily lives.

The fat and protein in black soldier fly larvae have been used by more and more countries and regions to make certain human foods.

It doesn’t look delicious. Image source: gbif

Is it really environmentally friendly?

Perhaps some people have already thought that since black soldier flies have such a wide range of uses, will there be the kind of extra resource consumption and environmental pollution that is common in previous biological farming? Will it be another case of "taking money from Peter to pay Paul" like the painful lessons learned in human history?

Black soldier fly, image source: gbif

A scholar conducted an investigation on a black soldier fly farm in the Netherlands. If it is only used as a raw material to provide humans with the same amount of protein and fat, the resources consumed by breeding black soldier flies are relatively less than those of other animals. Moreover, their food comes from the feces and leftover food of various animals, so there is no need to build factories or farms dedicated to making special feed, which reduces the consumption of additional land and plant resources.

In addition, the larvae of black soldier flies convert the carbon in their food into protein and fat, so they do not produce methane and only emit a small amount of carbon dioxide.

Swiss scientists have conducted statistics on the amount of carbon dioxide emitted by black soldier flies, and the results show that the total amount of carbon dioxide they emit after digestion is only 1/47 of that emitted by compost.

What are we waiting for for the environmentally sustainable resource industry of black soldier flies? Given that black soldier flies and their larvae have so many advantages, why are there still so few factories that specialize in breeding them?

The main reason is that people feel uncomfortable psychologically. People's long-standing aversion to flies has increased their concerns and worries about this industry. As this article uses the term "larvae" more often, rather than another simpler and more direct term: "maggots", it is to avoid people's psychological discomfort as much as possible.

Imagine if your food was labeled as “protein and fat are derived from maggots”, how much appetite would you have? If your cosmetics were labeled as “the raw material chitin is derived from flies and maggots”, would the majority of beauty lovers still be keen on it?

Before 2017, many developed countries and organizations, such as the United Kingdom and the European Union, even had laws restricting the use of black soldier flies and larvae, prohibiting their use as animal feed, let alone human food. After 2017, the relevant laws were gradually relaxed.

At present, it may take some time to develop this kind of organism with broad application prospects.

However, if food related to this creature really came on the market, would you eat it?

END

Review expert: Li Weiyang, a well-known science blogger.

Source: Tadpole Musical Notation

Editor: Heart and Paper