Silkworm. Silkworm cocoons

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: silkworm(see photo) domesticated species of insects.

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 silkworm cocoon 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, moreover, it differs high quality, therefore, it is beneficial 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 as large and heavy cocoons as 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 and placed in hot water, and then unwinded 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 different color- 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 the silk of the Chinese oak moth (Chinese oak moth).

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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Life of a silkworm

Silkworm (lat. Bombyx mori) is a nondescript little butterfly with dirty white wings that cannot fly at all. But it is thanks to her efforts that fashionistas around the world have been able to enjoy outfits made from beautiful soft fabric, the shine and colorful shimmer of which fascinates at first sight, for more than 5,000 years.

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

There are monovoltine, bivoltine and multivoltine breeds of silkworm in the world. The first give only one generation per year, the second - two, and the third - several generations per year. An adult butterfly has a wingspan of 40-60 mm, it has an underdeveloped mouthparts, so it does not feed throughout its entire life. short life. The wings of the silkworm are dirty white, with brownish bands 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 representatives of the peacock-eye family) is called grena. It has an elliptical shape, flattened on the sides, with one side slightly larger than 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 grenades depends on the breed - in general, Chinese and Japanese silkworms have smaller grenades than European and Persian ones.

Silkworms (caterpillars) emerge from the eggs, and all the attention of silk producers is focused on them. They grow in size very quickly, molting four times during their lifetime. The entire 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 the leaves of the mulberry tree (mulberry), so silk production is possible only in places where it grows. When the time comes for pupation, the caterpillar weaves itself into a cocoon consisting of a continuous silk thread ranging 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, only silkworms with white cocoons are bred for industrial needs.

Ideally, the butterfly should emerge from the cocoon on days 15-18, 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 eaten; 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 occurs in India and China.

The silkworm, or silkworm, caterpillar and butterfly, playing an important role 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”.

From a small tubercle under lower lip The caterpillar secretes a sticky substance, which upon contact with air immediately hardens and turns into a silk thread. The thread is very thin, but can withstand weight up to 15 grams.

All modern domestic animals and cultivated plants originated from wild species. The farm could not do without insects - silkworm butterflies. Over four and a half millennia of breeding work, it was possible to develop breeds that produce silk different colors, and the length of a continuous thread from one cocoon can reach a kilometer! The butterfly has changed so much that it is now difficult to say who its wild ancestor was. The silkworm is not found in nature; without human care it dies.

Let us remember that many other caterpillars weave a cocoon from silky threads, but only the silkworm has the properties we need. Silk threads are used to produce fabrics that are very durable and beautiful; they are used in medicine - for stitching wounds and cleaning teeth; in cosmetology - for the production of decorative cosmetics, such as eye shadow. Despite the appearance artificial materials, natural silk threads are still very widely used.

Who was the first to think of weaving silk fabric? As legend has it, four thousand years ago, a silkworm cocoon fell into a cup of hot tea that the Chinese Empress was drinking in her garden. Trying to pull it out, the woman pulled the protruding silk. The cocoon began to unwind, but the thread still did not end. It was then that the quick-witted empress realized that yarn could be made from such fibers. The Chinese emperor approved of his wife's idea and ordered his subjects to grow mulberry (white mulberry) and breed silkworm caterpillars on it. To this day, silk in China is called by the name of this ruler, and her grateful descendants have elevated her to the rank of deity.

It took a lot of work to get beautiful silk from butterfly cocoons. First, the cocoons need to be collected, discarded and, most importantly, unwound, for which they were dipped in boiling water. Next, the thread was strengthened with sericin, a silk glue, which was then removed with boiling water or a hot soapy solution.

Before dyeing, the thread was boiled and bleached. They painted it with plant pigments (gardenia fruits, moraine roots, oak acorns) or mineral pigments (cinnabar, ocher, malachite, lead white). And only then the yarn was woven - by hand or on a loom.

Already one and a half thousand years BC, clothing made of silk fabrics was common in China. In other Asian countries and among the ancient Romans, silk appeared only in the 3rd century BC - and then it was incredibly expensive. But the technology for making this amazing fabric remained a secret to the whole world for many centuries, because an attempt to take silkworms outside the Chinese Empire was punishable by death. The nature of silk seemed mysterious and magical to Europeans. Some believed that silk was produced by giant beetles, others believed that in China the soil was soft, like wool, and therefore, after watering, it could be used to produce silk fabrics.

The secret of silk was revealed in the 4th century AD, when a Chinese princess presented a gift to her fiancé, the king of Little Bukhara. These were silkworm eggs, which the bride secretly took from her homeland, hiding in her hair. Around the same time, the secret of silk became known to the Japanese emperor, but here sericulture was for some time a monopoly of the imperial palace alone. Then silk production was mastered in India. And from there, with two monks who placed silkworm eggs in the hollow handles of their staffs, they ended up in Byzantium. In the 12th-14th centuries, sericulture flourished in Asia Minor, Spain, Italy and France, and in the 16th it appeared in the southern provinces of Russia.

Silkworm pupa

However, even after Europeans learned to breed silkworms, most of the silk continued to be delivered from China. According to the Great silk road- a network of roads running from east to west - it was transported to all countries of the world. Silk outfits remained a luxury item; silk also served as an exchange currency.

How does a small white butterfly, the “silk queen,” live? Its wingspan is 40-60 millimeters, but as a result of many years of cultivation, the butterfly has lost the ability to fly. The mouthparts are not developed because the adult does not feed. Only the larvae have an enviable appetite. They are fed mulberry (mulberry) leaves. When fed with other plants that the caterpillars “agree” to eat, the quality of the fiber deteriorates. On the territory of our country, representatives of the family of true silkworms, which includes the silkworm, are found in nature only in the Far East.

Silkworm caterpillars hatch from eggs, the clutch of which is covered with a dense shell and is called grena. In sericulture farms, greens are placed in special incubators where the required temperature and humidity are maintained. After a few days, small, three-millimeter larvae of a dark brown color, covered with tufts of long hair, appear.

The hatched caterpillars are transferred to a special food shelf with fresh mulberry leaves. After several molts, the babies grow up to eight centimeters, and their bodies become white and almost naked.

The caterpillar, ready for pupation, stops feeding, and then wood twigs are placed next to it, to which it immediately switches. Holding onto one of the rods with its abdominal legs, the caterpillar throws its head first to the right, then back, then to the left and applies its lower lip with a “silk” tubercle to various places on the rod.

The caterpillars are fed mulberry leaves.

Soon a rather dense network of silk thread forms around it. But this is only the basis of the future cocoon. Then the “craftswoman” crawls to the center of the frame and begins to curl the thread: releasing it, the caterpillar quickly turns its head. The tireless weaver works on the cocoon for about four days! And then it freezes in its silken cradle and turns into a doll there. After about 20 days, a butterfly emerges from the pupa. She softens the cocoon with her alkaline saliva and, helping herself with her legs, barely gets out to begin searching for a partner for procreation. After mating, the female lays 300-600 eggs.

However, not every caterpillar is given the opportunity to turn into a butterfly. Most of the cocoons are sent to a factory to obtain raw silk. One centner of such cocoons yields approximately nine kilograms of silk thread.

It is interesting that the caterpillars, which later become males, are more diligent workers, their cocoons are denser, which means the thread in them is longer. Scientists have learned to regulate the sex of butterflies, increasing the yield of silk during its industrial production.

This is the story of the little white butterfly that made famous Ancient China and made the whole world worship its magnificent product.

Olga Timokhova, Candidate of Biological Sciences

The silkworm (lat. Bombyx mori) is an inconspicuous little butterfly with off-white wings that cannot fly at all. But it is thanks to her efforts that fashionistas around the world have been able to enjoy outfits made from beautiful soft fabric, the shine and colorful shimmer of which fascinates at first sight, for more than 5,000 years.

flickr/c o l o r e s s

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

flickr/Gustavo r..

There are monovoltine, bivoltine and multivoltine breeds of silkworm in the world. The first give only one generation per year, the second - two, and the third - several generations per year. An adult butterfly has a wingspan of 40-60 mm, it has an underdeveloped mouthparts, so it does not feed throughout its short life. The wings of the silkworm are dirty white, with brownish bands clearly visible on them.

flickr/janofonsagrada

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 representatives of the peacock-eye family) is called grena. It has an elliptical shape, flattened on the sides, with one side slightly larger than 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 grenades depends on the breed - in general, Chinese and Japanese silkworms have smaller grenades than European and Persian silkworms.

flickr/basajauntxo

Silkworms (caterpillars) emerge from the eggs, and all the attention of silk producers is focused on them. They grow in size very quickly, molting four times during their lifetime. The entire cycle of growth and development lasts from 26 to 32 days, depending on the conditions of detention: temperature, humidity, food quality, etc.

flickr/Rerlins

Silkworms feed on the leaves of the mulberry tree (mulberry), so silk production is possible only in places where it grows. When the time comes for pupation, the caterpillar weaves itself into a cocoon consisting of a continuous silk thread ranging 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, only silkworms with white cocoons are bred for industrial needs.

flickr/JoseDelgar

Ideally, the butterfly should emerge from the cocoon on days 15-18, 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 eaten; in all other countries they are considered just “production waste.”

flickr/Roger Wasley

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

History of silkworm breeding

The history of breeding of this butterfly, which belongs to the family of true silkworms (Bombycidae), is associated with ancient China, a country long years keeping the secret of making amazing fabric - silk. In ancient Chinese manuscripts, the silkworm was first mentioned in 2600 BC, and archaeological excavations in southwestern Shanxi province yielded silkworm cocoons dating back to 2000 BC. The Chinese knew how to keep their secrets - any attempt to export butterflies, caterpillars or silkworm eggs was punishable by death.

But all secrets are revealed someday. This happened with silk production. First, a certain selfless Chinese princess in the 4th century. AD, having married the king of Little Bukhara, she brought him silkworm eggs as a gift, hiding them in her hair. About 200 years later, in 552, two monks came to the Byzantine emperor Justinian and offered to good reward deliver silkworm eggs from distant China. Justinian agreed. The monks set out on a dangerous journey and returned the same year, bringing 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 decline 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 quite successfully bred in the Po Valley. In the XIV century. Sericulture began in the south of France. And in 1596, silkworms began to be bred for the first time in Russia - first near Moscow, in the village of Izmailovo, and over time - in the southern provinces of the empire that were more suitable for this.

However, even after Europeans learned to breed silkworms and unwind cocoons, most of the silk continued to be delivered from China. Long time this material was worth its weight in gold and was available exclusively to the rich. Only in the twentieth century did artificial silk somewhat replace 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 a very long time. Silk is lightweight and retains heat well. Finally, natural silk is very beautiful and can be dyed evenly.

Used sources.