The butterfly is a silkworm. Silkworm or how real silk is made Silkworm post

People know a lot about the virtues of silk, but few are familiar with the "creator" who gave the world this miracle. Meet the silkworm caterpillar. This small, modest insect has been spinning silk thread for 5,000 years.

Silkworms eat the leaves of mulberry (mulberry) trees. Hence the name of the 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.
• Pupa that is in a silk cocoon.
• Butterfly.

As soon as the head of the caterpillar darkens, the process of lenka will begin. Usually the insect sheds its skin four times, the body turns yellow, the skin becomes dense. So the caterpillar moves to a new stage, becomes a pupa, which is in a silk cocoon. Under natural conditions, a butterfly gnaws a hole in a cocoon and gets out of it. But in sericulture, the process follows a different scenario. Producers do not allow silkworm cocoons to mature until the last stage. Within two hours under the influence of high temperature ( 100 degrees), the caterpillar then dies.

The appearance of a wild silkworm

A butterfly with large wings. Domesticated silkworms are not very attractive (white with dirty spots). It is radically different from its “domestic relatives”, it is a 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.

1. Monovoltine, gives offspring once a year.
2. Polyvoltine, gives offspring several times a year.

The silkworm cannot live without human care, it cannot survive in the wild. The silkworm caterpillar is not able to get food on its own, even if it is very hungry, this is the only butterfly that cannot fly, which means that it is not able to finish off food on its own.

Useful properties of silk thread

The productive capacity of the silkworm is simply unique, in just a month it is able to increase its weight ten thousand times. At the same time, the caterpillar manages to lose "extra pounds" four times within a month.

It takes a ton of mulberry leaves to feed thirty thousand caterpillars, 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 threads of the silk cocoon can exceed 1 km. Now imagine how much a silkworm needs to work if, on average, 1500 cocoons are spent on one silk dress.

The saliva of the silkworm contains sericin, this substance protects silk from pests such as moths and mites. The caterpillar releases substances of a sloping origin (silk glue) from which it weaves a silk thread. Despite the fact that most of this substance is lost in the process of making silk, but even the little that remains in the silk fibers will be able to save the fabric from the appearance of a dust mite.


Thanks to serecin, silk has hypa allergenic 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 silk threads have been removed. Empty cocoons are used in cosmetology. Masks and lotions are prepared from them not only in professional circles, but also at home.

Silkworm food gourmet

Few people know about the nutritional benefits of the silk caterpillar. This ideal protein product, it is widely used in Asian cuisine. In China, the larvae are steamed and grilled, seasoned, usually with a huge amount of spices, you don't even understand what is “on the plate”.


In Korea, half-raw silkworms are eaten, for this they are lightly fried. It is a good source of protein.

Dried caterpillars are commonly used in traditional Chinese and Tibetan medicine. The most interesting thing is that mold fungi are added to the "medicine". Here is a useful silkworm.

What good intentions lead to

Few people know that the gypsy moth, which is the main pest of the US forestry industry, has spread as a result of a failed experiment. As they say, I wanted the best, but the following happened.

Silkworm (lat. Bombyx mori) - a nondescript little butterfly with dirty-white wings, which does not know how to fly at all. But it is thanks to her efforts that women of fashion from all over the world have been able to enjoy outfits made of fine soft fabric for more than 5000 years, the shine and colorful transfusion of which will fascinate at first sight.

Silk has always been a valuable commodity. The ancient Chinese - the first producers of silk fabric - kept their secret securely. For its disclosure, an immediate and terrible death penalty was imposed. They domesticated silkworms back in the 3rd millennium BC, and to this day, these small insects work to satisfy the vagaries of modern fashion.

There are monovoltine, bivoltine and polyvoltine silkworm breeds in the world. The former give only one generation per year, the latter two, and the third, several generations per year. An adult butterfly has a wingspan of 40-60 mm, it has an underdeveloped mouth apparatus, so it does not feed throughout its short life. The silkworm's wings are off-white in color; brownish bands are clearly visible on them.

Immediately after mating, the female lays eggs, the number of which varies from 500 to 700 pieces. The clutch of the silkworm (like all other members of the peacock-eyed family) is called green. It has an elliptical shape, flattened on the sides, and slightly more on one side than on the other. On the thin pole there is a depression with a tubercle and a hole in the center, which is necessary for the passage of the seed thread. The size of the grenae depends on the breed - in general, the Chinese and Japanese silkworms have less grenas than the European and Persian ones.

Silkworms (caterpillars) emerge from the egg, to which all the eyes of silk producers are riveted. They grow in size very quickly, molting four times during their life. The whole cycle of growth and development lasts from 26 to 32 days, depending on the conditions of detention: temperature, humidity, food quality, etc.

Silkworms feed on mulberry leaves, so silk production is possible only in places where it grows. When the time for pupation comes, the caterpillar braids itself with a cocoon consisting of a continuous silk thread from three hundred to one and a half thousand meters long. Inside the cocoon, the caterpillar transforms into a pupa. In this case, the color of the cocoon can be very different: yellowish, greenish, pinkish, or some other. True, for industrial purposes only silkworms with white cocoons are bred.

Ideally, the butterfly should emerge from the cocoon for 15-18 days, however, unfortunately, it is not destined to survive until this time: the cocoon is placed in a special oven and kept for about two to two and a half hours at a temperature of 100 degrees Celsius. Of course, the pupa dies, and the process of unwinding the cocoon is greatly simplified. In China and Korea, fried dolls are used for food, in all other countries they are considered just "production waste".

Sericulture has long been an important industry in China, Korea, Russia, France, Japan, Brazil, India and Italy. Moreover, about 60% of all silk production falls on India and China.

The silk caterpillar in 30 days increases in weight 10 thousand times

People know a lot about the virtues of silk, but few are familiar with the "creator" who gave the world this miracle. Meet the Silkworm. This small, modest insect has been spinning silk thread for 5,000 years.

Silkworms eat the leaves of mulberry (mulberry) trees. Hence the name of the 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.
• Pupa that is in a silk cocoon.
• Butterfly.

Extremely interesting breeding history such an insect as a silkworm.

The technology was developed a long time ago, in ancient China. The first mention of this production in Chinese chronicles dates back to 2600 BC, and silkworm cocoons found by archaeologists date back to 2000 BC. e. The Chinese elevated silk making to the status of a state secret, and for many centuries this was the country's obvious priority.

The ancient Chinese philosopher Confucius retells the legend of how man first learned about the silk thread. Empress Xi-Ling-shi found a cocoon under a mulberry bush and mistook it for some wonderful fruit. But it accidentally fell out of her hands into a cup of tea. Trying to get it, the empress pulled out a silk thread. In gratitude for this unexpected discovery, the Chinese elevated Xi-Ling-shi to the rank of a deity of the Celestial Empire. And engaged in the production of silk, at first, only the empress and women from among their entourage.

The Chinese knew how to keep their secrets - any attempt to take out butterflies, caterpillars or silkworm eggs was punishable by death. But all the secrets will be revealed someday, as happened with the production of silk. First, some selfless Chinese princess in v. BC, having married the king of small Bukhara, brought him silkworm eggs as a gift, hiding them in her hair. About 200 years later, in 552, two monks appeared to the emperor of Byzantium Justinian, who offered to deliver silkworm eggs from distant China for a good reward. Justinian agreed. The monks went on a journey and returned in the same year, bringing silkworm eggs in their hollow staves. Justinian was fully aware of the importance of his purchase and by special decree ordered the breeding of silkworms in the eastern regions of the empire. Asia Minor, and later in North Africa, in Spain. Much later, in the 13th century, Italy, the countries of North Africa, and in the 16th century - and Russia began to breed such worms and produce silk fabric.

The "Great Silk Road" - a caravan road that connected the West with the East in ancient times and stretched through the mountains of Central and Central Asia - served the development of geography as a science and trade between ancient countries.

In the 20th century, silk emerged with a serious rival - artificial chemical fibers, and then synthetic ones. Many of them surpass silk in strength, wrinkle less, and are more resistant to abrasion, but a person feels better in clothes made of natural silk.

Butterfly with big wings

What kind of insect is this - a silkworm?

The silkworm is not found in the wild today and is bred in special factories to obtain natural yarn. An adult is a fairly large insect - a light-colored butterfly, reaching 6 cm in length with a wingspan of up to 5-6 cm. Breeders of many countries are engaged in breeding various breeds of this interesting butterfly. After all, optimal adaptation to the characteristics of different localities is the basis for profitable production and maximum income. The silkworm cannot live without human care, it cannot survive in the wild. The silkworm caterpillar is not able to get food on its own, even if it is very hungry, this is the only butterfly that cannot fly, which means that it is not able to finish off food on its own.

Many breeds of silkworm have been bred: monovoltine - they give one generation a year, polyvoltine - two, and there are also species that give several broods a year. Despite its size, the silkworm butterfly does not fly, since it has long lost this ability. She lives only 12 days and during this time she does not even eat, having an undeveloped oral cavity.

Butterfly and ... Butterfly again

With the onset of the mating season, silkworm breeders place pairs of butterflies in separate bags. After mating, the female engages in 3-4 days laying eggs in the amount of 300-800 pieces per greenhouse, which has an oval shape with significantly varying sizes, which are in direct proportion to the breed of insect. The period of breeding of the worm also depends on the species - this may be in the same year, or maybe in the next.

Caterpillar- the next stage in the development of silkworm cocoons. The silkworm caterpillar hatches from eggs at a temperature of 23-25 ​​° C. In the factory, this happens in incubators at a certain humidity and temperature. Eggs develop within 8-10 days, then a brown, small up to 3 mm long silkworm larva appears from the grena, pubescent with hairs. Small caterpillars are placed in special trays and transferred to a well-ventilated warm room. These containers are a structure like a shelf, consisting of several shelves covered with a net and having a specific purpose - here the caterpillars are incessantly eating. They feed exclusively on fresh mulberry leaves, and the proverb "appetite comes with eating" is absolutely accurate for determining the voraciousness of caterpillars. Their need for food is growing exponentially, on the second day they eat twice as much food as on the first. The silkworm in 30 days increases in weight 10 thousand times.

Molting. By the fifth day of life, the larva stops, freezes and begins to wait for its first molt. When the color of the caterpillar's head darkens, it means that molting has begun. She sleeps for about a day, clasping a leaf with her legs, then, with a sharp straightening, the skin bursts, releasing the caterpillar and giving it the opportunity to rest and re-engage in satisfying hunger. For the next four days, she absorbs the leaves with an enviable appetite, until the next molt comes.

Caterpillar transformations Over the entire development period (about a month), the caterpillar molts four times. The last molt turns it into a rather large individual of a magnificent light pearl shade: the body length reaches 8 cm, the width is up to 1 cm, and the weight is 3-5 g with dense skin. The body has a large head with two pairs of well-developed jaws, especially the upper ones, called "mandibles". But the most important quality that is important for the production of silk is the presence of a tubercle under the lip in an adult caterpillar, from which a special substance oozes, which solidifies upon contact with air and turns into a silk thread.

Silk thread formation. This tubercle ends with two silk-secreting glands, which are long tubes with a middle part turned in the body of the caterpillar into a kind of reservoir that accumulates a sticky substance, which subsequently forms a silk thread. If necessary, the caterpillar releases a stream of liquid through the hole under the lower lip, which solidifies and turns into a thin, but strong enough thread. The latter plays a large role in the life of an insect and is used, as a rule, as a safety rope, since at the slightest danger it hangs on it like a spider, without fear of falling. In an adult caterpillar, the silk-secreting glands occupy 2/5 of the total body weight.

Stages of building a cocoon... Having reached adulthood after the 4th molt, the caterpillar begins to lose its appetite and gradually stops eating. By this time, the silk-secreting glands are filled with liquid so that a long thread constantly stretches behind the larva. This means that the caterpillar is ready to pupate. She begins to look for a suitable place and finds it on the cocoon-rods, timely placed by silk-breeders along the side walls of the stern "whatnot".

Having settled down on a twig, the caterpillar begins to work intensively: it alternately turns its head, applying its tubercle with a hole for the silk-secreting gland to different places on the cocoon, thereby forming a very strong network of silk thread. It turns out a kind of frame for future construction. Further, the caterpillar crawls to the center of its frame, keeping in the air by means of threads, and begins to twist the cocoon itself.

Cocoon and pupation. The caterpillars of silkworms use a continuous silk thread, the length of which is 300-900 meters, to curl their cocoons; there were also large cocoons, which were "wound" from 1500 meters of threads. When building a cocoon, the caterpillar turns its head very quickly, releasing up to 3 cm of thread for each turn. Its length for creating the entire cocoon is from 0.8 to 1.5 km, and the time spent on it takes four or more days. Having finished the work, the caterpillar falls asleep in a cocoon, turning into a pupa. The weight of the cocoon together with the pupa does not exceed 3-4 g. The silkworm cocoons are very diverse in size (from 1 to 6 cm), shape (round, oval, with bridges) and color (from snow-white to golden and purple). Experts have noticed that male silkworms are more diligent in weaving a cocoon. Their dwellings for pupae are distinguished by the density of the filament winding and its length.

And again the butterfly. After three weeks, a butterfly emerges from the pupa, which needs to get out of the cocoon. This is difficult, since it is completely devoid of the jaws that decorate the caterpillar. But wise nature solved this problem: the butterfly is equipped with a special gland that produces alkaline saliva, the use of which softens the wall of the cocoon and promotes the release of the newly formed butterfly. This is how the silkworm completes the circle of its own transformations.

However, the commercial breeding of the silkworm interrupts the reproduction of butterflies. Most of the cocoons are used to produce raw silk. After all, this is a ready-made product, it remains only to unwind the cocoons on special machines, having previously killed the pupae and treated the cocoons with steam and high temperature water (100 degrees), and the cocoon unwinds very easily after that. So, the silkworm, the cultivation of which on an industrial scale, will probably never lose its relevance, is an excellent example of a domesticated insect that brings a very considerable income.

It takes a ton of mulberry leaves to feed thirty thousand caterpillars, 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 threads of the silk cocoon can exceed 1 km. Now imagine how much a silkworm needs to work if, on average, 1500 cocoons are spent on one silk dress.

Useful properties of silk thread

The saliva of the silkworm contains sericin, this substance protects silk from pests such as moths and mites. The caterpillar releases substances of a sloping origin (silk glue) from which it weaves a silk thread. Despite the fact that most of this substance is lost in the process of making silk, but even the little that remains in the silk fibers will be able to save the fabric from the appearance of a dust mite.

Thanks to serecin, silk has hypa allergenic 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 silk threads have been removed. Empty cocoons are used in cosmetology. Masks and lotions are prepared from them not only in professional circles, but also at home.

Silkworm food gourmet

Few people know about the nutritional benefits of the silk caterpillar. This ideal protein product, it is widely used in Asian cuisine. In China, the larvae are steamed and grilled, seasoned, usually with a huge amount of spices, you don't even understand what is “on the plate”.

In Korea, half-raw silkworms are eaten, for this they are lightly fried. It is a good source of protein.

Dried caterpillars are commonly used in traditional Chinese and Tibetan medicine. The most interesting thing is that mold fungi are added to the "medicine".

What good intentions lead to

Few people know that the gypsy moth, which is the main pest of the US forestry industry, has spread as a result of a failed experiment. As they say, I wanted the best, but the following happened.

At the end of the nineteenth century, one person came up with the idea, to develop a new species, he planned to cross a silkworm and a gypsy moth. To get an insect that is less "picky about food", but at the same time it must produce silk thread. For this purpose, a batch of gypsy moth cocoons was brought from Europe to America. The experiment ended in complete failure. The scientist did not succeed in crossing these types of silkworms, but the gypsy moth "comfortably" settled down in America and now harms the forestry of the United States of America.

Only facts

• Silk thread is very strong and can withstand a lot of pressure. Silk ropes are more efficient than ropes made of steel of the same thickness.
• For the production of 1m of silk fabric, about 3000 silkworm cocoons are needed.
• Almost 80% of the world's silk production belongs to China.

To create enough silk thread to produce fabric for 1 dress, silkworms need to eat about 70 kg of leaves.

From its transformation into a pupa, a silkworm caterpillar eats mulberry leaves, which exceed its weight by 40 thousand times.

1 silkworm caterpillar in 4 weeks from the moment of its birth increases in size 25 times, its mass increases 12 thousand times.

The speed at which the silkworm produces its thread can be 15 meters per minute.

The silkworm caterpillar weaves its cocoon in 3 - 4 days.





Here is a useful silkworm.

The history of breeding this butterfly, belonging to the family of true silkworms (Bombycidae), is associated with ancient China, a country that for many years kept the secret of making an amazing fabric - silk. In ancient Chinese manuscripts, the silkworm was first mentioned in 2600 BC, and during archaeological excavations in the southwest of Shanxi province, silkworm cocoons dating back to 2000 BC were found. The Chinese knew how to keep their secrets - any attempt to take out butterflies, caterpillars or silkworm eggs was punishable by death.

But all the secrets are revealed someday. This happened with the production of silk. First, a certain selfless Chinese princess in the IV century. AD, having married the king of small Bukhara, brought him silkworm eggs as a gift, hiding them in her hair. About 200 years later, in 552, two monks came to the emperor of Byzantium Justinian, who offered to deliver silkworm eggs from distant China for a good reward. Justinian agreed. The monks embarked on a perilous journey and returned the same year, carrying silkworm eggs in their hollow staves. Justinian was fully aware of the importance of his purchase and, by a special decree, ordered the breeding of silkworms in the eastern regions of the empire. However, sericulture soon fell into decay and only after the Arab conquests flourished again in Asia Minor, and later throughout North Africa, in Spain.

After the IV Crusade (1203-1204), silkworm eggs came from Constantinople to Venice, and since then, silkworms have been bred quite successfully in the Po valley. In the XIV century. silkworm breeding began in the south of France. And in 1596 silkworms were first bred in Russia - first near Moscow, in the village of Izmailovo, and eventually in the more suitable southern provinces of the empire.

However, even after the Europeans learned to breed silkworms and unwind cocoons, most of the silk continued to be delivered from China. For a long time, this material was worth its weight in gold and was available exclusively to the rich. Only in the twentieth century artificial silk somewhat pressed natural silk on the market, and even then, I think, not for long - after all, the properties of natural silk are truly unique.
Silk fabrics are incredibly durable and last for a very long time. Silk is lightweight and keeps you warm. Finally, natural silk is very beautiful and lends itself to even dyeing.

Silkworm caterpillars hatch from eggs (grens) at a temperature of 23-25 ​​degrees Celsius. In large silkworm farms, for this purpose, the greenhouse is placed in special incubators, where the required temperature and humidity are maintained. It takes 8-10 days for the eggs to develop, after which small, only about 3 mm long, larvae are born. They are dyed dark brown and covered in tufts of long hair. The hatched caterpillars are transferred to a special stern shelf in a well-ventilated room with a temperature of 24-25 degrees Celsius. Each such shelf consists of several shelves covered with fine mesh.

Fresh mulberry leaves are on the shelves. The caterpillars eat them with such an appetite that Pasteur compared the loud crunch from the aft bunk to "the sound of rain falling on trees during a thunderstorm."

Caterpillar appetite grows by leaps and bounds. Already on the second day after hatching, they eat twice as much food as on the first day, etc. On the fifth day, the caterpillars begin to molt - they stop feeding and freeze, clutching the leaf with their hind legs and raising the front part of the body high. In this position, they sleep for about a day, and then the larva straightens strongly, the old skin bursts, and the caterpillar, which has grown and covered with delicate new skin, crawls out of its tight clothes. Then she rests for a few hours and then starts eating again. Four days later, the caterpillar falls asleep again before the next molt ...

During its life, the silkworm caterpillar molts 4 times, and then builds a cocoon and turns into a pupa. At 20-25 degrees Celsius, the development of the larva is completed in about a month, at higher temperatures, faster. After the fourth molt, the caterpillar already looks very impressive: its body length is about 8 cm, its thickness is about 1 cm, and its weight is 3-5 g. Its body is now almost naked and painted in a whitish, pearl or ivory color. There is a blunt, curved horn at the end of the body. The caterpillar has a large head with two pairs of jaws, of which the upper (mandible) is especially well developed. But most importantly, what makes the silkworm so attractive to humans is a small tubercle under the lower lip, from which a sticky substance oozes, which, upon contact with air, immediately solidifies and turns into a silk thread.

Here, into this tubercle, the excretory ducts of the two silk-secreting glands, located in the body of the caterpillar, flow. Each gland is formed by a long, convoluted tube, the middle part of which is expanded and turned into a reservoir in which the "silk liquid" accumulates. The reservoir of each gland passes into a long, thin duct, which opens with a hole in the papilla of the lower lip. When the caterpillar needs to cook the silk thread, it releases a trickle of liquid outside, and it freezes, turning into a paired thread. It is very thin, only 13-14 microns in diameter, but at the same time it can withstand a load of about 15 g.
Even the smallest caterpillar that has just emerged from the egg can already secrete a thin thread. Whenever the baby is in danger of falling down, she releases the silk thread and hangs on it, like a spider hangs on its web. But after the fourth molt, the silk-secreting glands reach especially large sizes - up to 2/5 of the total volume of the larva's body.

Now every day the caterpillar eats less and less and finally stops eating altogether. The silk gland at this time is already so full of liquid that a long thread stretches behind the larva, wherever it crawls. The caterpillar, ready to pupate, crawls restlessly on the shelf in search of a suitable place for pupation. At this time, silkworm breeders are placed on a stern shelf along the side walls of bunches of wood twigs - cocoons.

Having found a suitable support, the caterpillar quickly crawls onto it and immediately begins its work. Firmly clinging to one of the twigs with her abdominal legs, she throws her head first to the right, then back, then to the left and applies her lower lip with a “silk” papilla to various places of the cocoon. Soon a rather dense network of silk thread forms around it. But this is not yet the final building, but only its foundation. Having finished with the frame, the caterpillar crawls to its center - the silk threads at this time support it in the air and serve as the place where the real cocoon will be attached. And now his curling begins. When releasing the thread, the caterpillar quickly turns its head. Each turn requires 4 cm of silk thread, and the whole cocoon takes from 800 m to 1 km, and sometimes more! As many as twenty-four thousand times the caterpillar must shake its head to cocoon.

It takes about 4 days to make a cocoon. After finishing work, the exhausted caterpillar falls asleep in its silk cradle and turns into a chrysalis there. Some caterpillars, they are called carpet makers, do not make cocoons, but, crawling back and forth, line the surface of the stern shelf, as if with a carpet, while their pupa remains naked. Others, lovers of joint buildings, unite in twos or even threes and fours and weave a single, very large, up to 7 cm, cocoon. But these are all deviations from the norm. And usually the caterpillars weave a single cocoon, the weight of which, together with the pupa, is from 1 to 4 g.

Cocoons made by spinning caterpillars are very diverse in shape, size, and color. Some of them are perfectly round, others are oval with a sharp end or waist in the middle. The smallest cocoons do not exceed 1.5-2 cm in length, and the largest ones reach 5-6 cm.The color of the cocoons is completely white, lemon yellow, golden, dark yellow with a reddish tint and even greenish, depending on the breed silkworm. So, for example, the striped silkworm spins cocoons of pure white color, and the striped breed - beautiful golden yellow cocoons.
It is interesting that the caterpillars, from which male butterflies are later obtained, are more diligent silkworms: they weave denser cocoons, which require more silk thread.

After about 20 days, a butterfly emerges from the pupa, which faces the problem of how to get out of its silk shelter. Indeed, unlike a caterpillar, it does not have sharp jaws ... However, a butterfly has another adaptation. Her goiter is filled with alkaline saliva, which softens the wall of the cocoon. Then the butterfly presses its head against the weakened wall, energetically helps itself with its legs, and finally gets out. The silkworm butterfly does not shine with special beauty. The color of its plump shaggy body is either white with a light creamy pattern, or dark grayish brown. Females are larger than males.

The wingspan of the silkworm is about 4.5 cm, but these butterflies cannot fly. Most likely, they lost this ability in the process of constant human selection. After all, why do we need individuals in the silk industry that can fly away?
Domestic butterflies generally do not tend to bother themselves with unnecessary movements. They only move slowly on their thin legs, and wiggle their hairy antennae. During their short (about 12 days) life, they do not even feed. After alkaline saliva is released from their mouths, softening the cocoon, it closes forever.

Male silkworms change their behavior only when they meet individuals of the opposite sex. Then they liven up, circle around their friend, constantly waving their wings and actively touching their legs. During the mating season, the silkworm breeder puts pairs of butterflies in special gauze bags. A few hours after prolonged mating, the female begins to lay testicles - from about 300 to 800. This process takes her 5-6 days. Silkworm eggs are small, about 1.5 mm long. In winter, the greenhouse is kept at a relatively low temperature, and when spring comes and leaves bloom on the mulberry trees, the eggs are gradually revived, keeping them first at a temperature of 12 degrees Celsius, and then placing them in a brood incubator.

But, of course, not every caterpillar weaving a cocoon is given the opportunity to turn into a butterfly. Most of the cocoons are used to obtain raw silk. Pupae are killed by steam, and the cocoons are soaked and unwound on special machines. From 100 kg of cocoons, approximately 9 kg of silk thread can be obtained.
The silkworm spins the most beautiful yarn, but the caterpillars of some other butterflies are also capable of creating a silk thread, although a coarser one. So, from the cocoons of the East Asian atlas (Attacus attacus), phage silk is obtained, and from the cocoons of the Chinese oak peacock eye (genus Antheraea) - silk, which is used to make comb.

Natural silk is a wonderful fabric that has no analogues, its history is covered with ancient legends, and the production process has changed little over several millennia.

The publication will also be of interest to fans of felting. since Tussah and Mulberry silk, as well as silk handkerchiefs, feathering, cocoons and other materials are widely used in wet felting.

So where does silk come from.

Natural mulberry silk (

Probably, almost everyone knows that natural silk is provided by amazing worms - unsightly-looking caterpillars (larvae) of a silkworm. High quality silk is produced by these worms, and is often called "mulberry silk" or mulberry silk(Mulberry is a mulberry tree in translation from English), we call a mulberry tree mulberry and many love its fruits. And the larvae love the leaves and turn them into a silk thread.

Silkworm (scientific name Bombyx mori- lat. ) - a butterfly from the family Real silkworms, translated from Latin Bombyx mori means "death of the silkworm" or "dead silk". The name is explained by the fact that the butterfly is not allowed to fly out of the cocoon, it dies inside.

The butterfly is very impressive, it also met the name "silk moth": The wingspan is 4-6 cm, the caterpillar can grow up to 9 cm before pupation.

The Bombyx mori butterfly is believed to have evolved from the wild silk butterfly found in the mulberry trees of China. It was a very long time ago, it is believed that the history of silk production is at least 5000 years old, and over a long time of breeding butterflies in captivity, they have lost the ability to fly well. Females practically do not fly, males fly a little during the mating period, so to speak, in moments of elation.

The process of obtaining raw mulberry silk

A butterfly, hatching from a cocoon, mates with a male, and then begins to lay eggs. In 4-6 days, she lays up to 800 eggs, does not eat anything, because her oral apparatus is underdeveloped, and when she finishes her work it dies. Eggs are checked to select healthy, free from infection. Thus, the quality of the future silk and the reproduction of healthy butterflies are controlled.

Each egg in a week gives a larva of about 2-3mm with an unimaginable appetite. The larva should be fed regularly day and night for a month with mulberry leaves. The leaves are collected, sorted by hand and crushed. All this time, the larvae are in large trays with leaves placed one on top of the other in a special room with constant temperature and humidity. The larvae are surprisingly sensitive - there should be no drafts, odors or loud sounds in the room. What can happen if the conditions are not met? just the caterpillar will not cocoon, it will die, and all the efforts of the silkworm breeders will be in vain.

Caterpillars' appetite is constantly growing, and in a day they eat twice as much as in the previous day.

From the constant work of a huge number of silkworm jaws in the room, there is a hum, similar to the drumming of heavy rain on the roof.

On the fifth day of life, the larva freezes and sleeps for 24 hours, clinging tightly to the leaf. Then it sharply straightens up, and the old tight skin bursts, freeing the grown caterpillar. During the feeding period, the larvae change their skin 4 times, and are again taken for food.

Before pupation, caterpillars lose interest in food and begin to behave restlessly, constantly waving their heads back and forth. Under the lower lip there are glands that produce a silk substance. By this moment, they represent 2/5 of the body weight, and are so overwhelmed that a silk thread stretches behind the caterpillar.

The silkworm breeders move the caterpillars onto decks of leaves and branches, onto wooden trellises or special bundles of rods for cocooning.

First, the caterpillar is fixed on a twig or other base, creating a fluffy mesh-frame, and only then it cocoons a cocoon inside it. It begins to secrete a gelatinous substance, which hardens in air, forming a silk thread, and is wrapped with this thread in the shape of a figure of eight with rotational movements.

The thread consists of 75-90% of protein - fibroin and of the sticky substance sericin, which holds the threads together and prevents them from disintegrating; salts, fats and wax are also present in the threads. The caterpillar completes the cocoon in 3-4 days.

An interesting fact: the cocoons of males are made more carefully - they are denser and the length of the thread is longer than that of females. Those who have had to hold cocoons in their hands know how pleasant and silky they are to the touch.

After 8-9 days, the cocoon is ready to unwind. If you miss the time, after 2 weeks a butterfly will emerge from the cocoon, damaging the silk shell. Because the mouth apparatus of the butterfly is undeveloped, it does not gnaw through the cocoon, but secretes a special caustic substance that dissolves the upper part of the cocoon. Such a cocoon can no longer be unwound, the thread will be torn.

Therefore, the pupa is killed by heating the cocoons with hot air, and it suffocates in the cocoon, hence the name - "death of the silkworm" or "dead silk".

Here it is, a wonderful raw material for silk!

Cocoons are sorted by size and color and prepared for unwinding.

Rinse alternately in hot and cold water. The glue that holds the threads together, sericin, dissolves enough to unwind the thread.

According to all the sources studied, only the unwinding of the thread is mechanized at the present time, all the previous stages of production remain completely manual labor, as in ancient times.

The thread of one cocoon is very thin, therefore, when unwinding, from 3 to 10 threads are connected, thus obtaining raw silk. When one of the threads ends during the winding process, a new one is screwed to it, ensuring continuity. The remaining sericin (adhesive) in the thread helps to easily hold the ends of the thread together.

Raw silk requires further processing, it is wound into yarn and sent to a weaving factory. Factories buy silk by weight, but in the process of further processing such raw silk loses 25% of its weight - it is soaked to remove sericin residues, and bleached. To compensate for their losses, factories enrich silk with metal salts or water-soluble substances such as starch, sugar, glue or gelatin. Such impregnations make it possible to make a more economical weaving of threads, and to compensate for the loss of weight during weaving.

The sources do not say directly, but I think that is why natural silk gives decent shrinkage when washed. After all, if you wash salts or water-soluble impregnations from the fabric, the fabric will shrink the vacated space.

After unwinding the cocoons, a dead pupa remains, which is rich in protein and is eaten!

Now the silkworm culture is bred exclusively artificially. The cocoons that the silkworm caterpillar weaves can be of various shades from white to yellow and even grayish. The white cocoon variety contains the highest percentage of silk protein and produces the best quality silk. Produced by silkworms in Japan, China and India. Japan was the first to apply a scientific approach to the selection and breeding of silkworms in special laboratories, and now surpasses other countries in the efficiency of silk production, but China is in the lead in terms of production.

It is believed that France and Italy make silk fabric of higher quality than Asian countries. But the raw material, raw silk, is purchased by European manufacturers in China.

White Chinese silk fabric:

I met such an example: a woman's blouse needs a thread of 600 silkworm cocoons.

Traditional thai mulberry silk are obtained by processing yellow cocoons, which are produced by another species of silkworm Bombix Mori. The breeding process is similar.

Yellow cocoons contain less silk protein, and the thread is uneven - it has thickenings. When twisting, the thread turns out to be uneven, and on Thai-made silk cloth we see such characteristic thickenings of the thread. Again, the entire production process is manual labor, often even unwinding is done manually, so Thai silk is quite expensive and in Thailand is only available to wealthy Thais.

Thai silk fabric:

Natural "wild silk", "tussah silk (Tussah, tussar)"
What is it and how is it different from mulberry?

This silk is "wild" because the butterfly is grown in natural conditions, on bushes and trees, which are protected by canopies to the maximum. Silk breeders only look after the caterpillars and protect them from birds. Silk cocoons are harvested after the butterfly leaves the cocoon, and butterflies are completely different - Antheraea, a variety of nocturnal peacock eyes who are called oak silkworm... Butterflies are large, fly well, caterpillars grow up to 10 cm before pupation.

Chinese oak silkworm (there are Japanese, Mongolian and other varieties). The wingspan of a butterfly is 10-15 cm.

They can feed on oak, apple, plum or chestnut leaves, and their cocoons are brownish in color, coarser and stronger filament. Cocoons are large, several times larger than mulberries, and can reach the size of a small chicken egg.

Some sources write that the thread is difficult to unwind, and the silk fiber is combed from the cocoon, in others - that the thread unwinds excellently. I don't know where the truth is!

Also, wild silk is less lustrous, its thread does not shine evenly, but, as it were, shines.

Silk obtained in this way does not bleach to a pure white color. The fabric is durable and is often used for interior decoration and the production of very wearable dense suiting silk fabrics.

Personally, my hands have been itching to paint on her for a long time, there will be a chic skirt, but there’s no time.

Dyed Wild Silk Fabric:

I hope, dear readers, that the article was interesting to you. Personally, in the process of writing, I learned a lot of new things for myself and understood, evaluating the scale of manual labor, why real natural silk cannot be cheap :)

In the photo in the publication, most likely, small private farms in Asia. In China, it is very common for farmers to grow silkworms and then sell cocoons by weight for further processing.

The article was written using materials from various Internet sites.

Interestingly, the aforementioned sticky substance sericin is named after the ancient people of Sera, who, according to the records of historians that have come down to us (Herodotus), have been making silk since ancient times.
As you can see, silk is produced by various silkworms, not only mulberry ones.

The Siberian silkworm is widespread on the territory of Russia, which is a pest:

"With favorable weather conditions for development, they are able to significantly increase their numbers in a short period of time. Thus, an outbreak of mass reproduction of harmful forest insects occurs. The total area of ​​active foci of pests and diseases in 2001 amounted to more than 10 million hectares. Almost 70% Siberian and gypsy moths in this area accounted for Siberian and gypsy moth foci in Yakutia on an area of ​​6 million hectares became extinct after carrying out extermination measures and under the influence of natural causes.

The most dangerous pests in Siberia are the Siberian silkworm (the main range is the Irkutsk Region, the Republic of Buryatia and the Krasnoyarsk Territory) and the black barbel (the main range is the Krasnoyarsk Territory). The Siberian silkworm has a pronounced ecological variability, differing in different parts of the range in the set of preferred forage breeds and the features of the population dynamics, which allowed A.S. Rozhkov (1963) identify several regions where it feeds on certain types of forage plants and outbreaks of its mass reproduction occur with similar dynamics (Fig. 6). The area of ​​forests damaged by this dendrophage in only 40 years of the XX century (1930-1970) amounted to more than 8 million hectares only for Central Siberia (Kondakov, 1974).

Fir cancer is the most widespread among forest diseases (on 445 thousand hectares). The main area of ​​this disease in Siberia is the Kemerovo region.

The general deterioration of the forest pathological situation in the forests of the Russian Federation, in addition to the biological characteristics of pests and diseases, is caused by a complex of factors unfavorable for forest ecosystems and a number of organizational shortcomings of the forest protection service, such as a limited number of specialists in the regions, insufficient financing of forest pathological expeditionary surveys, extermination measures, etc. "

The distribution area of ​​the Siberian silkworm:

The harmfulness of the Siberian silkworm, according to A.S. Rozhkov (1963):
1 - the greatest harm; 2 - significant harm; 3 - minor harm; 4 - possible harm.

That is, even with the current harsh climate of Yakutia and the Krasnoyarsk Territory, Siberia, the silkworm actively reproduces, posing a threat to forests. In the past, Siberia was a much more suitable place in terms of the rich flora and fauna, the remains of which are found by scientists during excavations. A preserved piece of the tropical jungle of Primorye clearly illustrates what the climate was like in the past. When the warm Pacific current worked to heat the Far East and Siberia.

Actually, in Primorye, the northern border of the range of the silkworm now passes:

Sericulture - breeding silkworms to produce silk. According to Confucian texts, silk production using the silkworm began around the 27th century BC. e., although archaeological research allows us to talk about the breeding of silkworms as early as the Yangshao period (5000 BC). In the first half of the 1st century A.D. e. sericulture came to ancient Hotan,, and at the end of the III century - to India. Later it was introduced in other Asian countries, in Europe, in the Mediterranean. Sericulture has become an important industry in the economies of several countries such as China, the Republic of Korea, Japan, India, Brazil, Russia, Italy and France. Today, China and India are the two main producers of silk, accounting for about 60% of the world's annual production.

Khotan, historical background:
The history of the city is inextricably linked with the functioning of the Great Silk Road, which from here went either to the south, to India, or to the west, through the gorges of the Pamir. In ancient times, the oasis was inhabited by speakers of the Tocharian language, who early adopted Buddhism and whose mummies were discovered by European researchers at the beginning of the 20th century.
It is likely that the local monks were the first to introduce the Buddhist doctrine to the Chinese, who were attracted to Khotan by supplies of ornamental stone, which was highly valued at the court of the emperor - jade.

From about the 2nd century BC. e. The oasis is inhabited by the Saka Iranian-speaking tribes, who have left quite numerous monuments of Buddhist literature in the Khotanosak language of the 1st millennium BC. e. The foundation of the city itself and the receipt of the name known to us (Iran. Xvatan) is associated with their appearance. Starting from the 9th-10th centuries, the Khotanosak language was gradually replaced by the Turkic dialects.

The Khotan oasis (called 和 阗 in old Chinese texts) marked the limit of the spread of Chinese borders during the Han empires (in 73 AD troops of Ban Chao) and Tang (in the 630s there was a Chinese border outpost). According to legend, back in the 5th century, a Chinese princess, married to a Khotanese prince, secretly brought silkworm pupae out of the Middle Kingdom in her lush hairstyle. Thus, Khotan became the first sericulture center outside China; it was from here that the secret of its production leaked to Persia and Byzantium.

In the 10th century Khotan was dominated by the Kashgar princes. During the periods of their greatest power, the rulers of Tibet also tried to subjugate the oasis. Visiting the city in 1274, Marco Polo admired the quality of the local fabrics.