The silkworm, or silkworm, is a caterpillar and butterfly that plays an important economic role in silk production. The caterpillar feeds exclusively on mulberry leaves. A closely related species, the wild silkworm, lives in East Asia: in the northern regions of China and the southern regions of the Primorsky Territory of Russia.
The silkworm is the only fully domesticated insect (and all the others in China were already imported domesticated, not found in nature in the wild. Its females even “forgot how” to fly. The adult insect is a fat butterfly with whitish wings with a span of up to 6 cm. Dried caterpillars infected with a fungus Beauveria bassiana is used in Chinese folk medicine.
Silkworm caterpillars curl cocoons, the shells of which consist of a continuous silk thread m long and up to 1500 m in the largest cocoons.
The caterpillars eat leaves non-stop both day and night, which is why they grow very quickly. A change in the color of the caterpillar's head to a darker color signals the beginning of molting. After the caterpillar has gone through four molts, its body becomes slightly yellow and its skin becomes denser, which indicates that the caterpillar begins to turn into a pupa, wrapping itself in a silk thread. Having passed the pupal stage, the butterfly gnaws the cocoon and emerges. But the silkworm is not allowed to survive to this stage; the cocoons are kept for 22.5 hours at a temperature of about 100 °C, which kills the caterpillar and simplifies the unwinding of the cocoon.
Silkworm in art In 2004, the famous multi-instrumentalist, songwriter and leader of his own group Oleg Sakmarov wrote a song called “Silkworm”. In 2006, the group Flëur released a song called “Silkworm”. In 2007, Oleg Sakmarov released the album “Silkworm”. In 2009, the group Melnitsa released the album “Wild Herbs”, which contains a song called “Silkworm”.
People know a lot about the benefits of silk, but few people know the “creator” who gave this miracle to the world. Meet the mulberry caterpillar. For 5,000 years, this small, humble insect has been spinning silk thread.
Silkworms eat the leaves of mulberry (mulberry) trees. Hence the name silkworm.
These are very voracious creatures; they can eat for days without a break. That is why hectares of mulberry trees are specially planted for them.
Like any butterfly, the silkworm goes through four life stages.
- Larva.
- Caterpillar.
- A pupa located in a silk cocoon.
- Butterfly.
As soon as the caterpillar's head darkens, the lenching process begins. Usually the insect sheds its skin four times, the body becomes yellow, and the skin becomes dense. So the caterpillar moves on new stage, becomes a pupa, which is located in a silk cocoon. IN natural conditions the butterfly gnaws a hole in the cocoon and squirms out of it. But in sericulture, the process follows a different scenario. Manufacturers do not allow silkworm cocoons to “ripen” until the last stage. Within two hours of exposure high temperature (100 degrees), the caterpillar then dies.
Appearance of a wild silkworm
Butterfly with large wings. Domesticated silkworms are not very attractive (the color is white with dirty spots). It is radically different from its “domestic relatives”; it is very beautiful butterfly with bright large wings. Until now, scientists cannot classify this species, where and when it appeared. 
In modern sericulture, hybrid individuals are used.
- Monovoltine, produces offspring once a year.
- Polyvoltine, produces offspring several times a year.
The silkworm cannot live without human care; it is not able to survive in the wild. The silkworm caterpillar is not able to get food on its own, even if it is very hungry; it is the only Butterfly that cannot fly, which means it is not capable of getting food on its own.
Useful properties of silk thread
The productive ability of the silkworm is simply unique; in just a month it is capable of increasing its weight ten thousand times. At the same time, the caterpillar manages to lose “extra pounds” four times within a month. 
To feed thirty thousand caterpillars you will need a ton of mulberry leaves, enough for the insects to weave five kilograms of silk thread. The usual production rate of five thousand caterpillars yields one kilogram of silk thread.
One silk cocoon gives 90 grams natural fabric. The length of one of the silk cocoon threads can exceed 1 km. Now imagine how much work a silkworm needs to do if, on average, 1,500 cocoons are spent on one silk dress.
Silkworm saliva contains sericin, a substance that protects silk from pests such as moths and mites. The caterpillar secretes matting substances of sheer origin (silk glue) from which it weaves a silk thread. Despite the fact that most of this substance is lost during the manufacturing process of silk fabric, the little that remains in the silk fibers can protect the fabric from the appearance of dust mites. 
Thanks to serecin, silk has hypoallergenic properties. Due to its elasticity and incredible strength, silk thread is used in surgery for suturing. Silk is used in aviation; parachutes and balloon shells are sewn from silk fabric.
Silkworms and cosmetics
Interesting fact. Few people know that a silk cocoon is an invaluable product; it is not destroyed even after all the silk threads have been removed. Empty cocoons are used in cosmetology. They are used to prepare masks and lotions not only in professional circles, but also at home.
Silkworm food for gourmets
Few people know about the nutritional properties of the mulberry caterpillar. This ideal protein product, it is widely used in Asian cuisine. In China, maggots are steamed and grilled, seasoned with a huge amount of spices, and you won’t even understand what is “on the plate.” 
In Korea, half-raw silkworms are eaten and lightly fried. This is a good source of protein.
Dried caterpillars are commonly used in Chinese and Tibetan folk medicine. The most interesting thing is what they add to the “medicine” molds. This is how useful the silkworm is.
What good intentions lead to
Few people know that the gypsy moth, which is a major pest of the US forestry industry, was spread as a result of a failed experiment. As they say, I wanted the best, but what happened was the following.
The silkworm is very interesting insect, which has been known to man since ancient times as silk source. According to some data mentioned in Chinese chronicles, the insect became known as early as 2600 BC. The process of obtaining silk was a state secret for centuries in China, and silk became one of the clear trade advantages.
Starting from the 13th century, other countries, including Spain, Italy, and North African countries, mastered the technology of silk production. In the 16th century, technology reached Russia.
Nowadays, the silkworm is actively bred in many countries, and in Korea and China it is used not only to produce silk, but also for food. The exotic dishes that are prepared from it are distinguished by their originality, and silkworm larvae are used for the needs of traditional medicine.
India and China are leaders in silk production and it is in these countries that the number of silkworms is greatest.
What does a silkworm look like?
Yours unusual name this insect has earned it thanks to the tree on which it feeds. Mulberry, a tree also called mulberry, is the only source of food for the silkworm.
Silkworm caterpillar eats a tree day and night, which can even lead to its death if the caterpillars occupy such trees on the farm. To produce silk on an industrial scale, these trees are grown specifically to feed insects.
The silkworm goes through the following life cycles:
The silkworm butterfly is a large insect, and its wingspan reaches 6 centimeters. It has a white color with black spots; there are notches on the wings, in the front part of them. Pronounced comb mustache distinguish males from females, in whom this effect is almost invisible.
The butterfly has practically lost the ability to fly and modern individuals spend their entire lives without rising into the sky. This was caused by their very long detention in unnatural living conditions. Moreover, according to available facts, insects stop eating food after turning into butterflies.
The silkworm acquired such strange features because it was kept at home for many centuries. This has led to the fact that now the insect cannot survive without human guardianship.
Over the years of its breeding, the silkworm has managed to degenerate into two main species: monovoltine and multivoltine. The first species lays larvae once a year, and the second - up to several times a year.
Hybrid silkworms can have many differences in characteristics such as:
- body shape;
- wing color;
- dimensions and general shape of the butterfly;
- dimensions of the pupa;
- color and shape of caterpillars.
The larvae or eggs of this butterfly scientific community are called grena. They have a laterally flattened oval shape, with elastic transparent film. The dimensions of one egg are so small that per gram of weight their number can reach two thousand.
Immediately after the butterfly lays its eggs, they have a light milky or yellowish color. As time passes, changes occur, leading to the appearance of a pink tint in the larvae, and then to a complete change in color to purple. If the color of the eggs does not change over time, it means the larvae have died.
Silkworm eggs have a fairly long maturation period. He puts them in summer months: in July and August, and then they hibernate until spring. The processes occurring in them at this time slow down significantly in order to survive the effects of low winter temperatures.
If the grena overwinters at temperatures not lower than +15 degrees, then there is a risk of poor development in future caterpillars, so in winter it is necessary provide for grains optimal temperature regime. Caterpillars appear before leaves have time to grow on the trees, so grena is stored in refrigeration units at temperatures from 0 to -2 degrees throughout this period.
The caterpillars of this butterfly are also called silkworms, which cannot be considered a scientific name. Externally, silkworm caterpillars look like this:
Immediately after birth, the caterpillar has a very small size and weight, not exceeding half of one milligram. Despite this size, all biological processes in the caterpillar proceed normally, and it begins to actively develop and grow.
The caterpillar has very developed jaws, pharynx and esophagus, due to which all consumed food is absorbed very quickly and well. Each of these little caterpillars has more than 8,000 muscles, allowing them to bend into intricate poses.
In forty days, the caterpillar grows to more than thirty times its original size. During the period of growth, she sheds her skin, which for natural reasons becomes small for her. This is called molting.
During molting, the silkworm caterpillar stops eating tree leaves and finds a separate place for itself, usually under the leaves, where it tightly attaches itself to them with its legs and freezes for some period. I also call this period the caterpillar's sleep.
As time passes, the head of a renewed caterpillar begins to emerge from the old skin, then it comes out entirely. At this time you cannot touch them. This can lead to the fact that the caterpillar simply does not have time to shed its old skin and dies. During its life, the caterpillar molts four times.
The intermediate stage in the transformation of a caterpillar into a butterfly is the cocoon. Caterpillar creates a cocoon around itself and inside it turns into a butterfly. These cocoons are of greatest interest to humans.
The moment when a butterfly should be born and leave its cocoon is very easy to determine - it begins to move literally a day before, and you can hear light tapping sounds inside. This knocking appears because at this time the already mature butterfly is trying to free itself from the skin of the caterpillar. A curious fact is that the time of birth of the silkworm butterfly is always the same - from five to six in the morning.
A special liquid, similar in consistency to glue, which is secreted by butterflies, helps them free themselves from the cocoon by splitting it.
The lifespan of a moth is limited to only twenty days, and sometimes they do not even live up to 18 days. In this case it is possible meet long-livers among them who live for 25 and even 30 days.
Due to the fact that the jaws and mouth of butterflies are not sufficiently developed, they cannot feed. The main task of the butterfly is procreation, and during their short life they manage to lay many eggs. In one clutch, a female silkworm can lay up to a thousand of them.
It is noteworthy that even if an insect loses its head, egg laying process will not be interrupted. The butterfly body has several nervous systems, which allows her to continue laying and live for a long time, even in the absence of such a significant part of the body as the head.
Silkworm or Silkworm
The silkworm is the name given to the silkworm caterpillar. He is from the family of true silkworms, of which there are about a hundred species. Their caterpillars weave a cocoon from silk: in it the transformation of the pupa into a butterfly occurs. Some people have so much silk in their cocoon that by skillfully unwinding it, you can get threads suitable for making fabrics. Coarse varieties of silk are obtained from the cocoons of the Chinese oak peacock eye and some other silkworms (Philosamia, Telea). However, the best silk is produced by the silkworm. This butterfly is a real pet, it is completely dependent on humans. Not like bees, which even without people wildlife they can live well.
Where does the silkworm come from and who is its wild ancestor?
Many researchers believe that its homeland is the Western Himalayas, some regions of Persia and China. Theophylla mandarin butterfly lives there, darker in color than the silkworm, but generally similar to it, and most importantly, can interbreed with it, producing hybrid offspring. Perhaps the Chinese began to breed this butterfly in ancient times, and after thousands of years of skillful selection, the silkworm was obtained - in the human economy the most useful insect after the bee. Artificial silk today successfully competes with natural silk, and yet the annual world production of silk obtained from silkworms amounts to hundreds of millions of kilograms.
When and how long ago did they start breeding silkworms? The legend says: 3,400 years ago, a certain Fu Gi made musical instruments with strings from silk threads. But the real breeding of the silkworm and the constant use of its silk for the production of fabrics began later: approximately four and a half thousand years ago. As if Empress Xi Ling Chi was the initiator of this useful work (for which she was elevated to the rank of deity, and every year this significant event celebrated with ritual holidays).
At first, only empresses and high-ranking women were engaged in silk production. They kept the secrets of this matter secret. “For more than 20 centuries, the Chinese jealously guarded the monopoly of silk and protected it with laws punishing with death or torture anyone who sought to take abroad the eggs of the wonderful silkworm or divulge the secret of breeding and unwinding cocoons” (J. Rostand).
Twenty centuries is a very long time; hardly any other secrets have been kept for so long. But sooner or later the secret ceases to be secret. This is what happened with sericulture. Whether it's true or false, ancient texts say that in the 4th century AD, a Chinese princess brought her husband, the ruler of Bukhara, a priceless marriage gift - silkworm eggs. She hid them in her elaborate hairstyle.
In the same century, sericulture began to develop in some parts of India. From here, apparently (this story is probably known to many), Christian monks carried silkworm eggs and mulberry seeds in hollow staves, the leaves of which feed the caterpillars that produce precious silk. The eggs brought by the monks to Byzantium did not die; caterpillars hatched from them and cocoons were obtained. But later, sericulture, which began here, died out and only in the 8th century flourished again in the vast territory captured by the Arabs - from Central Asia to Spain.
“Our main centers of sericulture are located in Central Asia and Transcaucasia. Their position is determined by the distribution of the host plant, which is the mulberry tree. The advancement of sericulture further north is hampered by the lack of cold-resistant mulberry varieties” (Professor F.N. Pravdin).
Silkworms eat the leaves of this tree with a loud crunch, which Pasteur compared to “the sound of rain falling on trees during a thunderstorm.” This is when there are a lot of worms and they all eat. And towards the end of their larval life they eat continuously - day and night! And in any position: squeezed by neighbors, lying on their backs, on their sides and eating and eating - in a day they eat as much greenery as they themselves weigh.
They eat and grow. A tiny caterpillar emerges from the egg, about three millimeters long. And after 30-80 days, the silkworm, which has completed its development, is already 8 centimeters long and a centimeter thick. It is whitish, pearly or ivory. On its head it has six pairs of simple eyes, tactile antennae and, most importantly, what made it so valuable in the human economy - a small tubercle under the lower lip. An adhesive substance oozes from the hole at its end, which upon contact with air immediately turns into a silk thread. Later, when he weaves a cocoon, we will see how this natural silk spinning machine works.
Silkworms, strictly speaking, only eat mulberry leaves. We tried feeding it with other plants: blackberry leaves, for example, or lettuce. He ate them, but he grew worse, and the cocoons were not of the first quality.
So, first eating the soft parts of the leaves, and then, when they mature, the veins, even the petioles, the silkworm grows quickly. In the first days, it doubles its weight every day, and during its entire larval life it increases it 6-10 thousand times: before pupation it weighs 3-5 grams - more than the smallest mammals, some shrews and bats.
Frozen and hard as glass, the worm does not die. If you warm it up, it comes to life, eats again calmly, and later weaves a cocoon. But in general he is thermophilic. The most favorable temperature for him is 20-25 degrees. Then it grows quickly: its larval life, if there is enough food, is 30-35 days. When it's colder (15 degrees) - 50 days. You can make it complete all the processes necessary for the caterpillar to grow and prepare for transformation in 14 days, if you feed it abundantly and keep it at 45 degrees.
10 days after the last, fourth molt, the worm’s appetite is no longer the same as before. Soon he stops eating altogether and begins to crawl around restlessly...
Class - Insects
Squad - Lepidoptera
Family - Silkworms
Genus/Species - Bombyx mori
Basic data:
DIMENSIONS
Length: caterpillar - 8.5 cm.
Wingspan: 5 cm.
Wings: Two pairs.
Oral apparatus: the caterpillar has one pair of jaws, and the adult butterfly has an atrophied oral apparatus.
REPRODUCTION
Number of eggs: 300-500.
Development: from egg to pupa - time depends on temperature; from pupa to butterfly hatching 2-3 weeks.
LIFE STYLE
Habits: The silkworm (see photo) is a domesticated species of insect.
What it eats: mulberry leaves.
Lifespan: An adult silkworm lives 3-5 days, a caterpillar - 4-6 weeks.
RELATED SPECIES
There are about 300 species of silkworms in the world, such as the Chinese oak silkworm and the satin moth.
The ancient Chinese domesticated the silkworm 4.5 thousand years ago. They obtained silk from cocoons woven by silkworm caterpillars to transform into an adult butterfly. The beautifully woven cocoon of the silkworm is formed by a single silk thread, the length of which can reach one kilometer.
THE SILKWORTH AND MAN
The natural fiber called silk is also produced by many other species of insects, but only the silkworm produces it in sufficient quantities. large quantities and, in addition, it is of high quality, so it is profitable to breed silkworms in captivity. The ancient Chinese invented a way to unwind fiber and turn it into a strong thread. The first silk products appeared from the cocoons of wild silkworms. However, the Chinese soon began to breed them in artificial conditions and sought to select the largest and heaviest cocoons possible for further breeding. As a result of such attempts, modern silkworms were bred, which are much larger than their wild ancestors. True, they cannot fly and are completely dependent on humans.
Silkworm cocoons are softened with hot steam, placed in hot water, and then unwound in special factories to produce yarn. To make fabrics, threads are always twisted several strands together because they are very thin.
LIFE CYCLE
The silkworm is currently not found in the wild. The ancient Chinese domesticated the silkworm 4.5 thousand years ago. Since all this time a careful selection of individuals was carried out for further breeding in captivity, the modern silkworm is significantly larger than its distant ancestor. In addition, he is unable to fly. The caterpillar reaches its maximum sizes six weeks after birth. Before the cocoon is formed, it stops feeding, becomes restless, crawls back and forth in search of a convenient place to securely attach itself. Having attached itself to the stem, the caterpillar begins to spin a silk cocoon. Silk fiber is a secretion of paired arachnoid glands, which are located in several longitudinal folds on the caterpillar's body and reach its lower lip. When turning into a pupa, the caterpillar secretes one solid thread up to 1 kilometer long, which it wraps around itself. Silkworm cocoons can be of different colors - yellowish, white, bluish, pink or greenish. After the caterpillar transforms into a pupa, the next stage begins - the transformation into an adult butterfly.
WHAT DOES IT EAT?
Caterpillars must eat almost continuously. They feed on mulberry leaves, eating them at an incredible speed.
The caterpillar, born from an egg, has a length of 0.3 cm and weighs 0.0004 g, and after some time its length is up to 8.5 cm and its weight is 3.5 g. Sometimes caterpillars also eat the leaves of other plants . However, observations have shown that caterpillars fed with mixed food grow much slower, and the quality of the silk fiber they produce changes - the thread becomes thicker than that of caterpillars fed only mulberry leaves. The caterpillars grow for up to 6 weeks, then they stop eating and spin a cocoon, inside which they turn into an imago (adult).
GENERAL PROVISIONS
Nowadays, cheap synthetic fabrics have greatly replaced natural silk, and yet products made from it, as before, remain popular.
Even 4 thousand years ago, silkworms were bred in China to produce silk. For a long time now, this moth and its larvae have not been able to exist without human help. Adult insects have completely lost the ability to fly, and caterpillars would rather die of hunger than crawl to look for suitable food. For more than 2 thousand years, China maintained a monopoly on sericulture. Any attempt to remove grena (a clutch of silkworm eggs) was punishable by death. There was an ancient caravan route, which was called the “Great Silk Road”. The fact is that in the countries of Europe and the Middle East, silk fabrics were highly valued. And not only for the beauty of silk clothes. The most important thing is that in such clothes a person was less bothered by lice and fleas! This is why for many centuries the silk trade was the main source of income for the people of China. In 552, the pilgrim monks managed to bring a silkworm to Constantinople. Then Emperor Justinian issued a special order, which ordered him to engage in sericulture in the Byzantine Empire. China's monopoly on silk has come to an end. IN Western Europe They began breeding silkworms in 1203-1204, when the Venetians, after the IV Crusade, brought the silkworm to their homeland.
INTERESTING FACTS. DID YOU KNOW THAT...
- The annual production volume of raw silk is about 45 thousand tons. The main producers are Japan and China, South Korea, Uzbekistan and India.
- According to legend, the silkworm came to Europe thanks to two monks who hid it in reeds.
- Legend has it that China lost its monopoly on silk production in 400 AD, when a Chinese princess, who was marrying an Indian Raja, secretly took silkworm eggs with her when leaving her country.
- Silk made from silkworm threads is called “noble” silk.
- Silk yarn is made from Chinese silk oak silkworm(Chinese oak saturnia).
LIFE CYCLE OF THE SILKWORTH
Eggs: the female lays up to 500 eggs on a leaf and dies soon after.
Larvae, hatched from eggs, black, covered with hairs. Hatching time depends on temperature.
Caterpillar: During development, the larva molts several times until it becomes white and smooth, without eyelashes.
Cocoon: The caterpillar feeds intensively on leaves for 6 weeks, and then begins to look for a suitable twig. On it she spins a cocoon from silk with which she surrounds herself.
Adult silkworm: the butterfly mates shortly after emerging from the cocoon. The female secretes a special substance with a strong odor, which the male detects. By smell, with the help of special hairs on the enlarged antennae, the male determines the location of the female.
WHERE DOES IT LIVE?
The silkworm is native to Asia. Nowadays, silkworms are raised in Japan and China. There are many farms in India, Turkey, Pakistan, as well as in France and Italy.
PROTECTION AND PRESERVATION
The ancient Chinese domesticated the silkworm 4.5 thousand years ago. Now silkworms are bred on special farms.
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