BIOLOGICAL FEATURES OF THE SILKMORTH

We know more about silk and sericulture than about small
com an insect that gave humanity a wonderful silk-
I twist the thread. Silkworm belongs to the type Arthropod-
gikh, class Insects, order Lepidoptera, family
Real silkworms, genus Silkworm. He is on-
insects with a full cycle of transformation, that is, their development
development goes through four stages: egg (grena), caterpillar, ku-
pin, butterfly (Fig. 1).

Rice. 1. Stages of development of the silkworm:
a - grain; b - caterpillar; c - pupa; g - adult insect -
butterfly
The silkworm differs from other insects
some features related to the fact that it is on
for five thousand years was an object of artificial
th selection, which was carried out by a person. As a result
The silkworm has become completely dependent on humans and can
exist only thanks to his tutelage: mulberry caterpillars
silkworms do not crawl away in search of food, even if
very hungry, and his butterflies have completely lost their ability to
ability to fly and feed independently. It is believed that
The ancestor of the silkworm was the wild silkworm, which
ry lived in China and Japan. However, the exact origin
of this insect remains unknown.
There are a large number of breeds of mulberry silk
strand. In sericulture at the present stage, mainly
various hybrids are used, since they are more tolerant
Do you. Silkworm breeds are divided into monovoltine-
nal, which give one generation per year, and multivoltine,
giving several generations. In addition, the breeds differ
are classified according to morphological characteristics, namely: color,
shape, structure of cocoons, size and color of caterpillars.
The economic characteristics of the breed include productivity
cocoons, yield of dry cocoons after marinating pupae
and their drying; to the technical properties of cocoons - silkworms -
strength, unwinding of the cocoon shell and silk yield -
raw material, technical properties of mulberry.
In sericulture, silkworm eggs are called
Green. They are oval in shape and slightly flattened
on the sides, covered with an elastic translucent shell.
The eggs of the silkworm are so small that
a gram contains from 1500 to 2000. Freshly deposited
Grena has a straw-yellow or milky-white color -
ku, then its color changes. During the first two or three
for a day it turns pink, then turns brown-violet
howl and finally purple-ash. If the grain has been saved
its original color, this means that it died.
At the egg stage, the silkworm hibernates. This period of rest
lasts from mid-summer to spring of next year and is called
occurs through diapause. During wintering, metabolic processes
the embryo in the egg slows down. Thanks to this, it increases
This is the ability of grena to withstand low winter temperatures
rature, and the emergence of caterpillars from eggs is also regulated. If in
Gren's diapause period was stored at air temperature
15 °C, then during the incubation period it develops unevenly
but the caterpillars hatch before the leaves appear on the silk
Kowice. Therefore, for timely revival (manifestation)
activity) of the grena in the spring during the incubation period of its laying
blow on winter storage into the refrigerator, where she finds-
90-120 days at a temperature of 2-4 °C.
The caterpillar is the larval stage in the development of the shell-
hogmoth. Since ancient times, this stage in sericulture was called shel-
columbus worm, although, from the point of view of biological science,
this name is incorrect.
The caterpillar has an elongated body. It consists of
head, chest and abdomen, which ends in a horny
appendage There are three pairs on the ventral side of the body
pectoral and five pairs of abdominal legs. External chitinous layers
caterpillar covers perform a protective function and at the same time
are precisely its exoskeleton, to which the
Xia muscles.
A silkworm caterpillar just emerging from
eggs, very small. Its weight is only 0.5 mg. But she wants
Eats well and grows quickly. The caterpillar's body has all the non-
necessary for normal life. She is located
lays powerful jaws, pharynx, esophagus, has
well-developed crop, intestines, circulatory and excretory
new system. All this helps the silkworm caterpillar -
Yes, actively absorb food. This tiny creature has
4,000 muscles, which is eight times more than a human. This is
one should hardly be surprised at the truly acrobatic
properties of caterpillars. The silkworm is a cold-blooded animal,
therefore, his respiratory system delivers oxygen to his organs
system, not the circulatory system. This happens as follows:
at once: on the sides, along the body of the caterpillar, there are 9
chalet; from them oxygen is carried through the respiratory tubes-tracheas
steps into numerous smaller branches,
which end in tracheoles that penetrate everything
tissues and organs of the caterpillar body.
During its life - 20-38 days - the caterpillar increases
in size 30 times and in weight 10,000 times. Moreover, the speed
with which growth processes occur in the mulberry caterpillar
silkworm, truly fantastic. After all, the length of her body
increases by one and a half times per day, and weight by 400 times, then
every hour its “fullness” increases 18 times! Animal-
farmers involved in pig breeding, about such natural
I can’t even dream about it. Naturally, when
with intensive growth, the old skin eventually becomes
The small one curls and the silkworm exchanges it for a new one. This period
In the life of a caterpillar, silkworm breeders call it molting. During
she stops eating and begins to look for a place to
to easily change old clothes to new ones. Having found him,
the caterpillar attaches the abdominal legs to the under-
lays down and freezes, raising the front part of the body. Such co-
The state of torpor is what silkworms call “sleep.” Touch
the caterpillar during “sleep” is not allowed, since it may not be shed
shed the old skin and die. When the caterpillar starts
come to life, the old covers are torn, and pain appears first
shaya black shiny head. Silkworm caterpillars
yes, those on the verge of two ages are easy to recognize
by the disproportionately large head. For a while
the faded caterpillar is resting, waiting for the soft
covering the body, head and legs, and then with renewed vigor
starts eating.
The period between two molts is called instar.
During its life, the caterpillar goes through four molts and,
therefore, five ages, each of which is sufficient
You can definitely tell by the color. Caterpillars first
They are dark brown, almost black in color. In
in the second age they become lighter, especially in the chest area.
They begin to develop a specific carpet color
ka. Over time, the caterpillars lighten even more.
The silkworm caterpillar has a rather complex
new internal structure, like any living organism. But
for us the most important element internal structure
caterpillars is a silk-secreting gland - an organ of gu-
the senical stage of the silkworm. High productivity
ity of the silk-secreting gland, reaching the suggestive
body size for an insect, is the result of long-term
centuries-old artificial selection, which carried out
catcher If at the first age of the caterpillar the silk separator
gland makes up only 4% of body weight, then by the second
half of the fifth age there is a sharp increase in its
size, and it reaches 25-26% of the caterpillar’s ​​body weight. But
even during this period its mass is much less than the mass of silk,
which is secreted by the silkworm caterpillar when curling
ke cocona.
The silk-secreting gland consists of fibrin-secreting
body section, reservoir, paired and unpaired outlets
ducts In the gland, silk is formed and
shaping the silk thread. Its thickness is regulated by special
pressing apparatus - drawing mill, located in
unpaired duct of the silk gland. Notice-
telny technology invented by nature!
The pupa is an intermediate stage of shell development
hogworm, like any insect with complete metamorphosis.
She is inside the cocoon that protects her, so valuable
nogo for a person. A whole series of things happens inside the cocoon.
complex transformations. First, the caterpillar, having spun a cocoon,
takes shape and becomes a chrysalis, then the chrysalis becomes a butterfly.
You can easily determine when a butterfly is ready to hatch.
that. The day before the insect is released, the cocoon begins
stir. And if you listen carefully, you can
hear a quiet noise. This is a butterfly shedding its skin
pupae. In the morning she will be born. And he will do it in
strictly defined time - from five to six in the morning.
And so the butterfly releases a few drops of liquid, which...
which dissolves the glue (sericin) that glues the threads of the skin
kona. Then he spreads them with his front paws and goes out.
out. The body of the butterfly is quite massive, has a yellowish
Cotton-brown in color, consists of a head, chest and abdomen.
The oral organs are not developed. Therefore she cannot eat.
The silkworm butterfly lives only 10-12 days. Although
and among them there are long-livers, living 20-25 days. So
since a butterfly cannot eat, then, naturally, it quickly becomes
flies. Almost immediately after mating, the female silkworm
begins to lay eggs - Green. And do this
she can even be without a head, since she has a triple non-
rue system in every segment of your body. Therefore,
losing your head doesn't interfere with parts nervous system, located
located in the last segments of the abdomen, continue con-
role over oviposition. The number of eggs in a clutch can vary
range from 400 to 1000 pieces. Taking care of your offspring,
the butterfly glues each egg to the surface, and
strong enough.
Let's summarize. So, in its development it went
The pigtail goes through four stages throughout the year. In progress
eggs it exists from the moment the butterfly laid
egg, until next spring. Then the process happens
Greengrass incubation. It lasts on average 10-12 days. Follow-
The next stage of the silkworm is the caterpillar, which
Its development goes through five instars. Between ages-
There is a molting period. The first instar lasts 5-
6 days. This is followed by molting, the duration of which is
is a day. Second instar lasts from four to five
days, and again shedding within 24 hours. Duration
the third and fourth instars are also 4-5 days, and the
moulting between them - up to a day and a half. Fifth car
growth is longer and lasts 8-12 days. Then the goose
The silkworm's head curls within 3-4 days
cocoon. The last molt occurs in it, as a result
which the caterpillar turns into a pupa. The pupation process
Vania lasts 4-5 days. Then, within 12-18 su-
current, the last transformation occurs, and the pupa becomes
flutters like a butterfly. She comes out of the cocoon, mates, and that's it
starts again.

Niramin - Feb 23rd, 2017

The silkworm lives almost nowhere in the wild. The ancient Chinese domesticated this beneficial insect 4.5 thousand years ago. Despite the fact that the Chinese kept the process of producing natural silk a closely guarded secret for a long time, it became known in other countries where there are optimal conditions for raising silkworm larvae.

An ancient legend says that a Chinese princess, having married an Indian rajah, secretly took with her a clutch of silkworm eggs when she left China. It is worth noting that such an act was considered a state crime, and the princess faced the death penalty in her homeland. Nowadays, silkworm breeding is carried out on special farms in Asian countries: China, Japan, India, Pakistan, North and South Korea, Uzbekistan and Turkey. In addition, similar farms exist in Italy and France.

Like most insects, the silkworm looks different during its life, as it goes through several stages of development:

Grena stage - laying eggs.

Photo: Silkworm laying eggs.


Caterpillar (larval) stage.

Photo: Silkworm caterpillars.




Pupation (cocoon formation).

Photo: Silkworm cocoons.




The adult stage is a butterfly.







Photo: Silkworm - butterfly.


Butterfly white quite large in size with a wingspan of about 6 cm. In the process of natural selection, the silkworm butterfly lost the ability to fly. During its short existence of about 20 days, the butterfly does not feed. Its main function is mating and laying up to 1000 eggs in one clutch, after which the butterfly dies.

Depending on a certain temperature, black, hairy larvae emerge from the eggs. During its development, the larva molts several times and becomes a smooth white caterpillar.

It is the caterpillar that feeds exclusively on mulberry leaves.



Photo: Mulberry tree with fruits.

Any other plant food is not suitable for her. Hence the name of the insect. After 5 weeks of intensive calorie consumption, the caterpillar attaches itself to a suitable branch and forms a cocoon of silk thread, which it produces thanks to the presence of a special gland. The transformation of a caterpillar into a butterfly occurs in the cocoon. To obtain silk thread, farmers do not allow the butterfly to emerge from the cocoon. But a certain number of cocoons are still left for butterflies as successors to the next generation of silkworms.

Video: MULIWORM 6th grade

Video: What is it made of? (S7). Silk.

Video: Animals in history. Silkworm

Video: Silkworm cocoon Uzbekistan

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silkworm, silkworm photo
Bombyx mori Linnaeus, 1758

Silkworm(lat. Bombyx mori) is a butterfly from the family of true silkworms, which plays an important economic role in the production of silk. Domesticated in China around 3000 BC. e. A close species, and possibly the original form of the domesticated silkworm, the wild silkworm, lives in East Asia: in the northern regions of China and the southern regions of the Primorsky Territory of Russia.

  • 1 Description
  • 2 Life cycle
    • 2.1 Egg
    • 2.2 Caterpillar
  • 3 Human use
    • 3.1 Sericulture
    • 3.2 Other uses
  • 4 Silkworm in art
  • 5 Notes

Description

Relatively large butterfly with a wingspan of 40-60 mm. The color of the wings is dirty white with more or less distinct brownish bands. Fore wings with a notch on the outer edge behind the apex. The male's antennae are strongly combed, while the female's are combed. Silkworm butterflies have essentially lost the ability to fly. Females are especially inactive. Butterflies have an underdeveloped mouthparts and do not feed throughout their lives (aphagia).

Life cycle

The silkworm is represented by monovoltine (produce one generation per year), bivoltine (produce two generations per year) and polyvoltine (produce several generations per year) breeds.

Egg

After mating, the female lays eggs (on average from 500 to 700 pieces), the so-called eggs. Grena has an oval (elliptical) shape, flattened on the sides, and is somewhat thicker at one pole; soon after its deposition, one impression appears on both flattened sides. On the thinner pole there is a rather significant depression, in the middle of which there is a tubercle, and in its center there is a hole - a micropyle, intended for the passage of the seed thread. The size of the grain is about 1 mm in length and 0.5 mm in width, but it varies significantly between breeds. In general, European, Asia Minor, Central Asian and Persian breeds produce larger grains than Chinese and Japanese ones. Egg laying can last up to three days. Diapause in the silkworm occurs during the egg stage. Diapausing eggs develop in the spring of the following year, while non-diapausing eggs develop in the same year.

Caterpillar

caterpillars

A caterpillar emerges from an egg (called silkworm), which grows quickly and moults four times. After the caterpillar has gone through four molts, its body turns slightly yellow. The caterpillar develops within 26-32 days. The duration of development depends on the temperature and humidity of the air, the quantity and quality of food, etc. The caterpillar feeds exclusively on mulberry (mulberry) leaves. Therefore, the spread of sericulture is associated with the places where this tree grows.

While pupating, the caterpillar weaves a cocoon, the shell of which consists of a continuous silk thread ranging in length from 300-900 meters to 1500 m in the largest cocoons. In the cocoon, the caterpillar turns into a pupa. The color of the cocoon can be different: pinkish, greenish, yellow, etc. But for industrial needs, currently only silkworm breeds with white cocoons are bred.

The emergence of butterflies from cocoons usually occurs 15-18 days after pupation. But the silkworm is not allowed to survive to this stage - the cocoons are kept for 2-2.5 hours at a temperature of about 100 °C, which kills the pupa and makes it easier to unwind the cocoon.

Human use

Sericulture

Main articles: Sericulture, Silk, History of silk

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 Yangshao period (5000 BC). first half of the 1st century AD e. Sericulture came to ancient Khotan, and at the end of the 3rd century - to India. Later it was introduced in other Asian countries, in Europe, in the Mediterranean. Sericulture has become important in a number of countries such as China, 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.

Other uses

In China and Korea, fried silkworm pupae are eaten.

Dried caterpillars infected with the fungus Beauveria bassiana are used in Chinese folk medicine.

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”.
  • In the second episode of the animated series "Atomic Forest" there are intelligent silkworms.
  • In 2014, Robert Galbraith released his second Cormoran Strike novel, The Silkworm.

Notes

  1. Striganova B. R., Zakharov A. A. Five-language dictionary of animal names: Insects (Latin-Russian-English-German-French) / Ed. Doctor of Biology sciences, prof. B. R. Striganova. - M.: RUSSO, 2000. - P. 231. - 1060 copies. - ISBN 5-88721-162-8.
  2. Wild silkworm - Red Book Russian Federation
  3. Tikhonov A. Red Book of Russia. Animals and plants. - ROSMEN, 2002. - P. 414. - 10,000 copies. - ISBN 5-353-00500-7
  4. Patricia Buckley Ebrey. 2005. China: A Cultural, Social and Political History. Wadsworth Publishing. Page 7. ISBN 0-618-13387-9.
  5. Hill, John E. 2003. "Annotated Translation of the Chapter on the Western Regions according to the Hou Hanshu." 2nd Draft Edition. Appendix A.

silkworm, silkworm photo

Silkworm Information About

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 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, 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 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. For any attempt to remove grena (a clutch of silkworm eggs) there was a threat of death penalty. 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 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

A sticky substance is released from a small tubercle under the caterpillar's lower lip, 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 pets 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 of 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 advent of artificial materials, natural silk threads are still 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 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