Silkworm habitat. The silkworm is an insect. The lifestyle and habitat of the silkworm. In the photo there is a farm for the production of silk thread

Silkworm(lat. Bombyx mori) - the only domesticated insect

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 entire life. 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 for many 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, who offered to deliver silkworm eggs from distant China for a good reward. 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 eastern regions empires. However, sericulture soon fell into decline and only after Arab conquests blossomed 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 they have been quite successfully bred in the Po Valley silkworms. 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. For a 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.

Sources used.

Class: Insecta = Insects

Order: Lepidoptera = Lepidoptera, butterflies

Family: Bombycidae Latreille, 1802 = True silkworms

Silkworm or Silkworm

The silkworm is the name given to the silkworm caterpillar. He is from the family of true silkworms, of which there are about one hundred species. Their caterpillars weave a cocoon from silk: in it the transformation of the pupa into a butterfly occurs. Some people have so much silk in their cocoon that by skillfully unwinding it, you can get threads suitable for making fabrics. Coarse varieties of silk are obtained from the cocoons of the Chinese oak peacock eye and some other silkworms (Philosamia, Telea). However, the best silk is produced by the silkworm. This butterfly is a real pet, it is completely dependent on humans. Not like bees, which even without people wildlife they can live well.

Where does the silkworm come from and who is its wild ancestor?

Many researchers believe that its homeland is the Western Himalayas, some regions of Persia and China. Theophylla mandarin butterfly lives there, darker in color than the silkworm, but generally similar to it, and most importantly, can interbreed with it, producing hybrid offspring. Perhaps this butterfly began to be bred in ancient times the Chinese, and after thousands of years of skillful selection, the silkworm was produced - in the human economy the most useful insect after the bee. Artificial silk today successfully competes with natural silk, and yet the annual world production of silk obtained from silkworms amounts to hundreds of millions of kilograms.

When and how long ago did they start breeding silkworms? The legend says: 3400 years ago a certain Fu Gi made musical instruments with strings made of silk threads. But the real breeding of silkworms and constant use Its use of silk for textile production began later: approximately four and a half thousand years ago. As if Empress Xi Ling Chi was the initiator of this useful work (for which she was elevated to the rank of deity, and every year this significant event celebrated with ritual holidays).

At first, only empresses and high-ranking women were engaged in silk production. They kept the secrets of this matter secret. “For more than 20 centuries, the Chinese jealously guarded the monopoly of silk and protected it with laws punishing with death or torture anyone who sought to take abroad the eggs of the wonderful silkworm or divulge the secret of breeding and unwinding cocoons” (J. Rostand).

Twenty centuries is a very long time; hardly any other secrets have been kept for so long. But sooner or later the secret ceases to be secret. This is what happened with sericulture. Whether it's true or false, ancient texts say that in the 4th century AD, a Chinese princess brought her husband, the ruler of Bukhara, a priceless marriage gift - silkworm eggs. She hid them in her elaborate hairstyle.

In the same century, sericulture began to develop in some parts of India. From here, apparently (this story is probably known to many), Christian monks carried silkworm eggs and mulberry seeds in hollow staves, the leaves of which feed the caterpillars that produce precious silk. The eggs brought by the monks to Byzantium did not die; caterpillars hatched from them and cocoons were obtained. But later, sericulture, which began here, died out and only in the 8th century flourished again in the vast territory captured by the Arabs - from Central Asia to Spain.

“Our main centers of sericulture are located in Central Asia and Transcaucasia. Their position is determined by the distribution of the host plant, which is the mulberry tree. The advancement of sericulture further north is hampered by the lack of cold-resistant mulberry varieties” (Professor F.N. Pravdin).

Silkworms eat the leaves of this tree with a loud crunch, which Pasteur compared to “the sound of rain falling on trees during a thunderstorm.” This is when there are a lot of worms and they all eat. And towards the end of their larval life they eat continuously - day and night! And in any position: squeezed by neighbors, lying on their backs, on their sides and eating and eating - in a day they eat as much greenery as they themselves weigh.

They eat and grow. A tiny caterpillar emerges from the egg, about three millimeters long. And after 30-80 days, the silkworm, which has completed its development, is already 8 centimeters long and a centimeter thick. It is whitish, pearly or ivory. On its head it has six pairs of simple eyes, tactile antennae and, most importantly, what made it so valuable in the human economy - a small tubercle under the lower lip. An adhesive substance oozes from the hole at its end, which upon contact with air immediately turns into a silk thread. Later, when he weaves a cocoon, we will see how this natural silk spinning machine works.

Silkworms, strictly speaking, only eat mulberry leaves. We tried feeding it with other plants: blackberry leaves, for example, or lettuce. He ate them, but he grew worse, and the cocoons were not of the first quality.

So, first eating the soft parts of the leaves, and then, when they mature, the veins, even the petioles, the silkworm grows quickly. In the first days, it doubles its weight every day, and during its entire larval life it increases it 6-10 thousand times: before pupation it weighs 3-5 grams - more than the smallest mammals, some shrews and bats.

Frozen and hard as glass, the worm does not die. If you warm it up, it comes to life, eats again calmly, and later weaves a cocoon. But in general he is thermophilic. The most favorable temperature for him is 20-25 degrees. Then it grows quickly: its larval life, if there is enough food, is 30-35 days. When it's colder (15 degrees) - 50 days. You can make it complete all the processes necessary for the caterpillar to grow and prepare for transformation in 14 days, if you feed it abundantly and keep it at 45 degrees.

10 days after the last, fourth molt, the worm’s appetite is no longer the same as before. Soon he stops eating altogether and begins to crawl around restlessly...

Butterflies, thanks to which people have the opportunity to wear silk things, appeared on the planet a long time ago. Back in the fifth millennium BC new era Silkworm cocoons were used by people.

The wild silkworm, without knowing it, played a big role in the history of states ancient world. You can learn about this from the video.

Nowadays, the range of insect uses is very wide. Fried larvae and pupae are considered a delicacy in Korea. delicious dish, which they rush to feed guests, although Europeans do not consider them a delicacy. The larvae contain large number protein, which is why they are so popular among gourmets.

In addition, larvae are used to obtain medicines, in cosmetology, medicine, and the list goes on.

The leaders in silk production are India and China; the mulberry tree is found almost everywhere here, so the silkworm has all the conditions for its growth. Unfortunately, there are many more silk connoisseurs than those who are interested in this inconspicuous, but very hardworking insect.

Let's look at the features, characteristics of the insect, the reproduction process and try to answer the question - what role does the silkworm play in human life.

What does an insect look like?

The mulberry tree, or mulberry, is the only habitat for the silkworm. Caterpillars are so voracious that a tree can be left without leaves in one night, so gardening farms pay special attention to preserving trees from insect invasion. Silkworm breeding enterprises are always surrounded by hectares of mulberry plantations. IN industrial scale This tree is grown in compliance with all norms and requirements to provide the insects with adequate nutrition.

We owe the appearance of silk to caterpillars and butterflies, but to understand how an insect lives, we need to consider the entire process of its development.

The life cycle of an insect consists of the following stages:

adult moths mate, after which the female lays many small eggs (larvae);
small dark caterpillars emerge from the eggs;
the caterpillar lives on the mulberry tree, eats its leaves and grows quickly;
caterpillars create silkworm cocoons, after a while the caterpillar finds itself in the center of a cocoon of silk threads;
a pupa appears inside a skein of thread;
the pupa becomes a moth that flies out of the cocoon.

This process is interesting and continuous, like many other natural cycles.

You can learn interesting facts from the life of an ancient insect, which for many centuries was equal in value to gold, by watching the video.

The butterfly is white, with dark spots on the wings, large, its wingspan is 6 centimeters. In females the mustache is almost invisible, in males it is larger.

Over the years, butterflies have lost the ability to fly, and they can easily survive without food. They have become so “lazy” thanks to man that their life is unthinkable without human care and care. Caterpillars, for example, are unable to find their own food.

Varieties of silkworm

Modern science knows two types of silkworms.

The first type is called monovoltine . The larvae appear only once.

The second type is called multivoltine. More than one offspring appears.
Butterfly

Hybrids have external differences. They differ in the color of the wings, the shape of the body, the size of the pupa and butterflies. Caterpillars also have different colors and sizes. The possibilities of genetics have no limits; there is even a breed of silkworm with striped caterpillars.

What indicators are used to determine productivity?

Productivity indicators are:

number of cocoons, mostly dry;
do they unwind easily?
how much silk can be obtained from them;
quality and other characteristics of silk threads.

Caterpillar

Let's talk about green

Grena is nothing more than silkworm eggs. They are small, oval in shape, slightly flattened on the sides, covered with an elastic shell. The color of the grena changes from light yellow to dark purple; if the color does not change, this indicates that they have lost their vitality.

Grena takes a long time to ripen, somewhere from mid-summer until spring. In winter, metabolic processes occur much slower, this allows her to safely overwinter. The caterpillar should not hatch ahead of schedule, otherwise, due to the lack of mulberry leaves, it is in danger of death. Eggs can overwinter in the refrigerator, at temperatures from 0 to -2C.

Grena

Meet the silkworm caterpillar

Caterpillars, or as they were previously called, silk worms (photo below) look like this:

elongated, like all worms, body;
the head, abdomen and chest are clearly defined;
small horns on the head;
chitinous covers protect the body and are muscles.

Silkworm caterpillar

The caterpillar appears small, but viable, its appetite grows, so its size quickly increases. She eats around the clock, even at night. Walking near mulberry trees, you can hear a peculiar rustling sound - this is the work of the small jaws of voracious caterpillars. But their weight is not constant, because they lose it four times in their lives. A huge number of muscles allows the caterpillars to demonstrate real acrobatic tricks.

Watch the video and see for yourself.

In forty days, the body of the caterpillars increases significantly, they stop eating and molt, clinging to the leaf with their paws, they become motionless.

Photo of a caterpillar sleeping. Touching the caterpillar can interfere with the natural cycle and it will die, so you should not touch them. By molting four times, they change color four times. Silk is produced in the silk gland of caterpillars.

There was a chrysalis, and a butterfly appeared

It does not take much time for the cocoons to form. The caterpillar flies out of it like a butterfly. After molting, the caterpillar becomes a pupa, after which it becomes a butterfly.

You can learn how caterpillars turn into butterflies from the video.

Before the butterfly flies, the cocoons begin to move, a slight noise is heard inside, this is the rustling of the pupa’s skin, which the butterfly has no use for. They appear only in the morning hours - from five to six in the morning. Using a special adhesive substance, they dissolve part of the cocoon and get out of it.

No one considers them beauties, which cannot be said about their domestic relatives.

Butterflies have a short life - no more than 20 days, but sometimes they live for a whole month. Mating and laying eggs are their main occupation; they neglect food, since they do not have the opportunity to absorb and digest food. But there is no doubt about the strength of gluing of grain to a tree or leaf.

That's the whole short life of a worker - a silkworm, which has been useful to humans for almost five thousand years.

Information for the curious!

In addition to the fact that the insect cannot fly, it is also blind.
It only takes three to four days to create a cocoon, but during this time a silk thread 600-900 meters long is obtained. There are known cases when the unwinding thread was 1500 meters long. In terms of strength, a silk thread can be compared with steel, their diameter is the same, and it is not so easy to break the thread.
The quality of a silk product can be assessed by its color; the lighter it is, the better the quality. Silk items cannot be bleached.
Moths and mites, which can ruin clothes, do not pose a threat to silk fabrics. And the explanation for this is a substance that is in insect saliva, it is called sericin. To this we should add that silk has another advantage - its hypoallergenic properties. Elastic and durable threads have found application not only in textile industry. They are used in medicine, aviation and aeronautics.

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.

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.

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.

People know a lot about the benefits of silk, but few people know the “creator” who gave this miracle to the world. Meet the mulberry caterpillar. For 5,000 years, this small, humble insect has been spinning silk thread.

Silkworms eat the leaves of mulberry (mulberry) trees. Hence the name silkworm.

These are very voracious creatures; they can eat for days without a break. That is why hectares of mulberry trees are specially planted for them.

Like any butterfly, the silkworm goes through four life stages.

Larva.
Caterpillar.
A pupa located in a silk cocoon.
Butterfly.

As soon as the caterpillar's head darkens, the lenching process begins. Usually the insect sheds its skin four times, the body becomes yellow, and the skin becomes dense. So the caterpillar moves on new stage, becomes a pupa, which is located in a silk cocoon. IN natural conditions the butterfly gnaws a hole in the cocoon and squirms out of it. But in sericulture, the process follows a different scenario. Manufacturers do not allow silkworm cocoons to “ripen” until last stage. Within two hours of exposure high temperature (100 degrees), the caterpillar then dies.

Appearance of a wild silkworm

Butterfly with large wings. Domesticated silkworms are not very attractive (the color is white with dirty spots). It is radically different from its “domestic relatives”; it is very beautiful butterfly with bright large wings. Until now, scientists cannot classify this species, where and when it appeared.

In modern sericulture, hybrid individuals are used.

Monovoltine, produces offspring once a year.
Polyvoltine, produces offspring several times a year.

The silkworm cannot live without human care; it is not able to survive in the wild. The silkworm caterpillar is not able to get food on its own, even if it is very hungry; it is the only Butterfly that cannot fly, which means it is not capable of getting food on its own.

Useful properties of silk thread

The productive ability of the silkworm is simply unique; in just a month it is capable of increasing its weight ten thousand times. At the same time, the caterpillar manages to lose “extra pounds” four times within a month.

To feed thirty thousand caterpillars you will need a ton of mulberry leaves, which is enough for the insects to weave five kilograms of silk thread. The usual production rate of five thousand caterpillars yields one kilogram of silk thread.

One silk cocoon gives 90 grams natural fabric. The length of one of the silk cocoon threads can exceed 1 km. Now imagine how much work a silkworm needs to do if, on average, 1,500 cocoons are spent on one silk dress.

Silkworm saliva contains sericin, a substance that protects silk from pests such as moths and mites. The caterpillar secretes matting substances of sheer origin (silk glue) from which it weaves a silk thread. Even though most This substance is lost during the production of silk fabric, but even the little that remains in the silk fibers can protect the fabric from the appearance of dust mites.

Thanks to serecin, silk has hypoallergenic properties. Due to its elasticity and incredible strength, silk thread is used in surgery for suturing. Silk is used in aviation; parachutes and balloon shells are sewn from silk fabric.

Silkworms and cosmetics

Interesting fact. Few people know that a silk cocoon is an invaluable product; it is not destroyed even after all the silk threads have been removed. Empty cocoons are used in cosmetology. They are used to prepare masks and lotions not only in professional circles, but also at home.

Silkworm food for gourmets

Few people know about nutritional properties mulberry caterpillar. This ideal protein product, it is widely used in Asian cuisine. In China, maggots are steamed and grilled, seasoned with a huge amount of spices, and you won’t even understand what is “on the plate.”

In Korea, half-raw silkworms are eaten and lightly fried. This good source protein.

Dried caterpillars are commonly used in Chinese and Tibetan folk medicine. The most interesting thing is what they add to the “medicine” molds. That's how useful the silkworm is.

What good intentions lead to

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