When the volunteers settled in the "Moon Palace", a special group of "residents" also came. This group of "mystery guests" is closely watched by volunteers every day; Among them, a group of deputy captains Liu Dianlei praised them as low-key heroes in the cabin of "Moon Palace No. 1", revealing that it was "me" - mealworms.

Hello everyone, I am a mealworm, belonging to the genus Mealworm of the family Coleoptera, native to North America, known for its high protein content. The larval stage is slender and bright yellow, so it is also called a bread worm (I wonder if you think "I" is a little similar to a baguette?). ）

Comparison of mealworms and baguettes

Don't underestimate the role of "me", in the world's first four-biological chain biological regeneration life support system - "Yuegong-1", mealworms play a vital role. Not only can I provide volunteers with rich edible protein, but I can also decompose some of the waste in the cabin, accelerate the material recycling process, and also play a certain role in psychological regulation (whenever volunteers see "me", they are always happy).

Schematic diagram of mealworm action

There are about 1.5 million species of animals on the earth, of which insects account for more than one million species, accounting for two-thirds of all animal species, which shows the huge number and indispensable position of insect groups in the global ecosystem.

So, how did "we" mealworms get involved with space and gradually integrate into the process of space exploration?

To trace the origin of "me" in space, we must start with the first animal to enter space, the fruit fly. In July 1946, fruit flies flew into space as pioneers on the "V2 rocket" launched by the United States, ushering in a new era of animals exploring the universe as "astronauts" (they even flew to an altitude of 108 kilometers and finally returned to Earth safely by parachute.

In the decade of the sixties of the last century, the Soviet Union, France, China, the United States and other countries sent a variety of animals into space, including rats and dogs (China sent mice, house mice and dogs into space in 1964 and 1966 respectively).

In 1968, the Soviet Union launched its first spacecraft to orbit the moon, Zond 5, and at this historic moment, "I" mealworms were honored to be part of the carboard, which was also the closest the mealworm family came to the moon as "space travelers".

Picture of the Zond series of probes in the former Soviet Union

Although the entry of animals into space is no longer a hot topic of news after the successful landing of humans on the moon, the pace of animal participation in space exploration has never stopped. In 1990, Japan sent mealworms and tree frogs to Russia's Mir space station, although in this mission, "I" was not the protagonist, but only existed as a food and behavioral research object for tree frogs (this experience made "me" feel slightly aggrieved)

However, both in space and on Earth, mealworms have shown great value. On Earth, mealworm larvae are generally widely recognized as high-quality protein feeds for fish and poultry (this is similar to space applications, when will they truly "make their C-debut") [3-4]. As a high-protein resource insect, mealworms can also provide essential protein supplements for humans [5] and are highly regarded by Orientals for their delicious taste, thus joining the ranks of resource insects (it is a great honor to be regarded as a delicacy by humans).

Mealworm larvae cooked in the "Moon Palace".

In the micro-ecosystem of the "Moon Palace", as a high-protein and easy-to-breed living organism, which can adapt to the complex environment of space and become a delicacy on the table, why does "I", the mealworm, often relegate to a supporting role and become feed for other animals (which can't help but make "me" sad)? As the saying goes, "Maxima often has, but Bole does not often have", for "me", it should be changed to "Thousands of miles of insects are often there, and those who know pearls are not often there".

It wasn't until 2014 that the outlook changed, a year destined to go down in history, when "my" Bole-Professor Liu Hong's team of Beihang University finally appeared. After ten years of sharpening their swords, they successfully developed China's first and the world's third space base bioregenerative life support system (BLSS) ground-based comprehensive experimental device - "Yuegong-1", and completed a record 105 days of long-term high-closure integration experiments in China. In this experiment, they introduced "our" mealworm population into the animal chain link of BLSS for the first time, which immediately aroused widespread attention from the international industry, and it is widely believed that the introduction of mealworms into BLSS has opened up a new field of research, which is expected to be applied to the lunar and even Martian biological regeneration support system in the future, realizing the degradation of plant waste and providing high-quality animal protein for astronauts.

With the vigorous promotion of Professor Liu Hong's team, "we" mealworms have become a star in the limelight (a veritable "Internet celebrity") with a full schedule. Whenever the professor went abroad to participate in the conference, "I" also followed, although at first the foreign friends were afraid of "me", but under the patient science popularization and guidance of the team members, they tried to taste and commented that "the taste is a bit like fried potato sticks" (please, in terms of nutritional value, "I" can be far more than potato sticks!). ）。 It is this spirit of advocating science that makes mealworms famous in the field of international biological regeneration and life support and even in the field of foreign food. Nowadays, "Moon Palace No. 1" has attracted an endless stream of domestic audiences to visit, they are all amazed after witnessing the demeanor of "me", if you want to visit "me", be sure to make an appointment with the docent agent in advance!

Today, the international community has embraced insects as a sustainable food source for the future and an important source of protein for astronauts in space, and even mealworms have been recognized as a novel and unique food in Europe.

So, what exactly is it that makes "we" mealworms so widely recognized?

1. **Superior Nutritional Value**:

Mealworms contain all essential amino acids, most of which exceed the FAO/WHO/United Nations University (UHU) recommended standards, accounting for up to 44.7% of the total amino acid content.

Comparison of amino acid composition of mealworm larvae

Compared with mealworms that eat traditional feeds, as well as space food reserve candidates such as goat meat, beef, luncheon fish, and silkworms, mealworm larvae that feed on plant waste can have a dry weight protein content of 76.14%, while a fat content is only 6.44% [10-12]. Given that the FAO states that eating low-fat foods can help reduce the risk of cancer, mealworms are undoubtedly an ideal food for both health and nutrition, especially for astronauts.

2. **Waste Treatment Capacity**:

The larvae have digestive enzymes and microbial enzymes in the digestive tract that can degrade the cell walls of plants, fungi and bacteria, and the degradation rate of lignocellulose is as high as 45.74%, which can be called a small expert in degrading waste. In addition, the intestinal microbial structure of mealworm larvae cultivated in a closed environment is different from that of the outside world, and the number of some species related to metabolism and immune function, such as Bacillus, Lactococcus, Weissella, Escherichia and Clostridaceae, is relatively low.

3. **Easy to breed and process**:

Mealworms are cultivated under mild conditions (suitable temperature 28°C, humidity 70%), require less space (2.5 larvae per square centimeter), simple cultivation process, reduced manpower input, and convenient cooking methods.

Volunteers observe the growth of mealworm larvae

4. **Safe & Delicious**:

Since 2014, the Yuegong-1 team led by Professor Liu Hong has confirmed that mealworms are a healthy and safe food suitable for providing animal protein in aerospace life support systems [6-7,10-12]. In 2015, the European Food Safety Agency also listed mealworms as one of the most promising foods in the EU. In addition, studies have shown that the heavy metal content of mealworms is below the maximum allowable limit, which meets food safety standards [14]. As for the taste after cooking, Dong Chen, a volunteer of the "105 Days of the Moon Palace" experiment in 2014, described it as like french fries, while Liu Dianlei, a volunteer of the "Moon Palace 365" experiment, compared it to fried Zhi (cicada), and some people think it is more like a silkworm chrysalis. As Shakespeare said, "There are a thousand Hamlets in the eyes of a thousand people", and the deliciousness of mealworms needs to be tasted for yourself.