The silkworm is interesting. Silkworm: life cycle and nutrition of an insect. What are the characteristics of silkworm eggs

Description

Relatively large butterfly with a wingspan of 40 - 60 mm. The color of the wings is off-white with more or less distinct brownish bands. Forewings with notch on outer margin behind apex. The antennae of the male are strongly pectinate, the females are pectinate. Silkworm butterflies, in fact, have practically lost the ability to fly. Females are especially inactive. Butterflies have underdeveloped mouthparts and do not feed throughout their lives (aphagia).

Life cycle

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

Egg

After mating, the female lays eggs (500 to 700 on average), the so-called grena. Grena has an oval (elliptical) shape, flattened laterally, somewhat thicker at one pole; soon after its deposition, one depression appears on both flattened sides. At the thinner pole there is a rather significant depression, in the middle of which there is a tubercle, and in the center of it there is a hole - a micropyle, designed for the passage of the seed thread. The grain size is about 1 mm long and 0.5 mm wide, but it varies considerably depending on the breed. In general, breeds of European, Asia Minor, Central Asian and Persian give a larger gren than Chinese and Japanese. Egg laying can last up to three days. Diapause in the silkworm falls on the egg stage. Diapausing eggs develop in the spring of the following year, while non-diapausing eggs develop the same year.

Caterpillar

A caterpillar comes out of the egg (so-called silkworm), which grows rapidly and molts four times. After the caterpillar has gone through four molts, its body becomes 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 (tree) leaves. Therefore, the spread of sericulture is associated with the places where the mulberry tree (mulberry) 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 1,500 m in the largest cocoons. In the cocoon, the caterpillar turns into a chrysalis. The color of the cocoon can be different: pinkish, greenish, yellow, etc. But for the needs of industry, only silkworm breeds with white cocoons are currently bred.

The release of butterflies from cocoons usually occurs on the 15-18th day 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 caterpillar and simplifies the unwinding of the cocoon.

Human use

Sericulture

Sericulture- breeding of silkworms to obtain 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). In the first half of the 1st century A.D. e. sericulture came to ancient Khotan, and at the end of the 3rd century came to India. It was later introduced to Europe, the Mediterranean and other Asian countries. 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 a fungus Beauveria bassiana used in Chinese traditional 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 Flëur released a song called "Silkworm".
• In 2007, Oleg Sakmarov released the album "Silkworm".
• In 2009, the Melnitsa group released the Wild Herbs album, on which a song called Silkworm sounds.

Notes

Categories:

• Animals alphabetically
• Animals described in 1758
• real silkworms
• farm animals
• Pets

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See what "Mulberry silkworm" is in other dictionaries:

- (Votbuh mori), this butterfly. real silkworms (Bombycidae). Wingspan 40-60 mm, whitish. The body is massive. According to the number of generations per year, monovoltine (one), bivoltine (two), and polyvoltine (many) breeds of T. sh. Wintering... ... Biological encyclopedic dictionary

Silkworm, silkworm Dictionary of Russian synonyms. silkworm n., number of synonyms: 2 silkworm (2) ... Synonym dictionary

Butterfly of the true silkworm family. Not known in the wild; domesticated in China c. 3 thousand years BC e. to get silk. Bred in many countries, mainly in the East., Wed. and Yuzh. Asia. A close view of the wild silkworm lives in ... ... Large encyclopedic Dictionary

Butterfly. Caterpillar T. sh. called a silkworm, feeds on the leaves of the mulberry tree, curls a silk-rich cocoon, for the sake of getting a horn and gets divorced. Silkworm (: 21/2): 1 caterpillar; 2 dolls; 3 cocoon; 4 female laying eggs. ... ... Agricultural dictionary-reference book

Butterfly of the true silkworm family. Wingspan 4 6 cm, massive body. It feeds (caterpillar) on mulberry leaves. Not known in the wild; domesticated in China around 3000 BC. e. to get silk. Bred in many countries, ... ... encyclopedic Dictionary

- (bombyx mori) butterfly of the family Bombycidae. Wingspan 4 6 cm; has an underdeveloped mouth apparatus and does not feed. Caterpillar G. sh. feeds on mulberry leaves (See Mulberry) (or mulberry tree); inferior substitutes for it ... ... Great Soviet Encyclopedia

Bombyx mori (silkworm, silk moth) silkworm, silkworm. Lepidoptera insect , one of the first domesticated species (domesticated in China over 4000 years ago as a producer of valuable silk fiber ... ... Molecular biology and genetics. Dictionary.

- (Bombyx s. Sericaria mori) a butterfly belonging to the silkworm family (Bombycidae) and bred for the silk that is obtained from its cocoons. The body of this butterfly is covered with dense fluff, the antennae are rather short, comb-like; wings are small... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

The silkworm is a nondescript butterfly from the family of real silkworms, a detachment of mulberries. The insect was domesticated in China more than 3 thousand years ago, plays an important economic role in production natural silk, sericulture. In nature, there is a wild silkworm, which is considered a "derivative" of the domestic one. Dwells in East Asia, China, Primorsky Krai of Russia.

Appearance of a moth

The silkworm butterfly is rather large in size. The wingspan is 60 mm. The color is off-white with brown streaks. The body is divided into segments, on the head there are hairy comb antennae in males, less pronounced in females. Despite the significant size of the wings, the silkworm butterfly practically does not fly, leads a sedentary lifestyle due to domestication. oral apparatus underdeveloped throughout adulthood the insect does not feed.

Interesting!

The wild silkworm moth is quite beautiful, the color is close to white. Slightly smaller in size. At home, hybrids with different colors are bred for industrial purposes - pink, brown, brown. There is also a stripless silkworm. However, the white moth is more valued.

A photo of the silkworm is presented below. You can take a close look at the features appearance butterflies male, female. includes several stages:

• egg;
• larva;
• chrysalis;
• imago.

The duration of development depends directly on the conditions environment, availability of food.

Eggs

After fertilization, the female lays from 500 to 700 eggs - grain. The shape is oval, elongated, flattened on the sides. The size of one egg does not exceed 1 mm in length, 0.5 mm in width. On the one hand, along the length of the grain, there is a recess, on the other, a bulge. The color is off-white, milky, yellowish immediately after laying, purple towards the end of maturation of the larva. If the color scheme does not change, this means the death of the embryo inside.

The ripening period of grains is long, with a decrease in temperature, metabolic processes slow down, development stops. The female lays eggs in July-August. Development continues in early spring when the eggs hatch into larvae. At a constant high temperature of more than +15 degrees Celsius, larvae may appear in the same year.

Interesting!

Home silkworm eggs are placed in the refrigerator, where the temperature is maintained from 0 to -2 degrees Celsius. Under such conditions, a strong, healthy silkworm caterpillar appears in spring. If the wintering temperature is higher, the younger generation is born weak. This is due to the fact that the caterpillar appears too early, when there is not yet enough food for it.

Larva

The silkworm caterpillar resembles white worm before they were called that. The body is elongated with a head, abdomen, chest. On the head are small horns - appendages. On the inside of the body there are 8 pairs of legs, with the help of which the silkworm larva moves along the tree bark and leaves. The chitinous cover is quite dense, it performs the function of muscles. A photo of a silkworm caterpillar can be seen below.

Larvae appear extremely small, no more than 1 mm in length, but with a good appetite. exclusively with mulberry leaves, it is also a mulberry tree, which is why the name of the insect came about.

The full cycle of caterpillar development is 45 days. During this time, 4 molts occur. Until the last stage, the caterpillar increases in size up to 30 times. In conclusion, the caterpillar forms a cocoon of silk thread around itself, for the sake of which insects are grown. If you unfold one cocoon, you get a thread length of 300 to 1600 m.

Interesting!

Pupa of a silkworm of snow-white color. A butterfly develops inside for several days, independently gets out. Shortly before this, you can hear the noise, feel the movement in the cocoon.

The appearance of the imago

The formed silkworm moth secretes a special sticky substance that can dissolve the cover of the chrysalis, threads. The head is shown first, then the wings. For its birth, the butterfly chooses the time from 5 to 6 in the morning.

Within a few hours after birth, the mating process begins. The butterfly lives for about 20 days, but there are also centenarians who live up to 45 days. The male lives half as much. The butterfly does not eat anything, only reproduces the younger generation. Even being headless, the female does not stop this process.

The silkworm is grown specifically to produce silk threads, a person regulates the number of insects on his own. To obtain raw materials, moths are not allowed to be born, a cocoon is placed in conditions unfavorable for the development of adults.

On a note!

The silkworm does not harm a person, they do not fight with it, they specially create favorable conditions for nutrition and development. But it is a real pest, with which an intense struggle is being waged. The insect damages about 300 varieties of deciduous, coniferous plants. Keeps up with the unpaired, destroying any coniferous trees within its range.

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 new era silkworm cocoons were used by humans.

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

In our time, the range of use of the insect 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 a large number of protein, which is why they are so popular among gourmets.

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

The leaders in the production of silk 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 nondescript, but very hardworking insect.

Let's look at the features, characteristics of the insect, the process of reproduction 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 voracious so much that in one night a tree can be left without leaves, therefore, in horticultural farms, special attention is paid to preserving trees from insect invasion. Silkworm farms are always surrounded by hectares of mulberry plantations. AT industrial scale this tree is grown in compliance with all norms and requirements in order to provide insects with good nutrition.

We owe the appearance of silk to caterpillars and butterflies, but in order to understand how an insect lives, you need to consider the whole 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);
• little dark caterpillars emerge from the eggs;
• the caterpillar lives on the mulberry, eats its leaves and grows rapidly;
• caterpillars create silkworm cocoons, after a while the caterpillar is in the center of a cocoon of silk threads;
• a chrysalis appears inside the skein of threads;
• the chrysalis 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 equated with gold by its value, by watching the video.

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

Ability to fly for long years butterflies are lost, besides, they can easily do without food. They have become so “lazy” thanks to a person that their life is unthinkable without the guardianship and care of a person. Caterpillars, for example, are unable to find their own food.

Silkworm varieties

Two types of silkworm are known to modern science.

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

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

The 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 a different color and size. The possibilities of genetics have no limits, there is even a breed of silkworm with striped caterpillars.

What are the performance indicators?

Productivity indicators are:

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

Let's talk about grena

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 grena changes from light yellow to dark purple, if the color does not change, this indicates that they have lost their viability.

Grena ripens for a long time, somewhere from mid-summer to spring. In winter, metabolic processes are much slower, this allows her to safely winter. The caterpillar must hatch ahead of time otherwise, due to the lack of mulberry leaves, she is threatened with death. Eggs can overwinter in the refrigerator, at temperatures from 0 to -2C.

Meet the silkworm caterpillar

Caterpillars, or, as they used to be called, silk worms (photo below) look like this:

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

The caterpillar appears small, but viable, its appetite grows, so the size increases rapidly. She eats around the clock, even at night. Passing near the mulberry trees, you can hear a kind of rustling - these are the small jaws of voracious caterpillars. But their weight is not constant, because they drop it four times in their life. A huge amount of muscle allows the caterpillars to demonstrate real acrobatic stunts.

Watch the video and see for yourself.

For 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 during sleep. Touching the caterpillar can interfere with the natural cycle, it will die, so you can not touch them. Shedding four times, they change their color four times. Silk is produced in the silk gland of caterpillars.

There was a chrysalis, but a butterfly appeared

It doesn't take long for cocoons to form. The caterpillar flies out of it like a butterfly. After molting, the caterpillar becomes a chrysalis, after which it becomes a butterfly.

You can learn from the video how caterpillars turn into a butterfly.

Before the flight of the butterfly, the cocoons begin to move, a slight noise is heard inside, this is the rustling of the chrysalis skin, which the butterfly does not need. They appear only in the morning hours - from five to six in the morning. With a special sticky 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 have no opportunity to absorb and digest food. But there is no doubt about the strength of gluing grena to a tree or a leaf.

That's all short life worker - a silkworm, almost five thousand years of benefit to man.

Information for the curious!

• Besides the fact that the insect cannot fly, it is also blind.
• It takes only three or four days to create a cocoon, but during this time a silk thread 600-900 meters long is obtained. There are 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 judged by its color, the lighter it is, the better. Silk fabrics cannot be bleached.
• Moths and mites that can ruin clothes do not pose a threat to silk fabrics. And the explanation for this is a substance that is in the saliva of an insect, it is called sericin. To this should be added the fact that silk has one more advantage - its hypoallergenic properties. Elastic and durable threads have found application not only in the textile industry. They are used in medicine, aviation and aeronautics.

From a small tubercle under the lower lip of the caterpillar, a sticky substance is released, which, upon contact with air, immediately solidifies 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 are descended from wild species. Not without an insect on the farm - silkworm butterflies. For four and a half millennia of breeding work, it was possible to develop breeds that give 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 was its wild ancestor. In nature, the silkworm is not found - without human care, it dies.

Recall that many other caterpillars weave a cocoon of silky threads, but only in the silkworm they have the properties we need. Silk threads are used to produce fabrics that are very durable and beautiful; they are used in medicine - for sewing up wounds and cleaning teeth; in cosmetology - for the manufacture of decorative cosmetics, such as shadows. Despite the advent of artificial materials, natural silk threads are still widely used.

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

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

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

As early as one and a half thousand years BC, clothes made of silk fabrics were common in China. In other Asian countries and among the ancient Romans, silk appeared only in the 3rd century BC - and then it was fabulously expensive. But the manufacturing technology of this amazing fabric remained a secret for the whole world for many centuries, because an attempt to take the silkworm out of 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 earth was soft, like wool, and therefore, after watering, it could be used to produce silk fabrics.

The secret of silk was discovered in the 4th century AD, when a Chinese princess presented a gift to her fiancé, the king of Lesser Bukhara. Those were the eggs silkworm, which the bride secretly took out of her homeland, hiding in her hair. Around the same time, the secret of silk became known Japanese emperor, but here sericulture for some time was the 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 century it appeared in the southern provinces of Russia.

Silkworm pupa

However, even after the 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 taken to all countries of the world. Silk outfits remained a luxury item, silk also served as an exchange currency.

How does the little one live? white butterfly— "silk queen"? Its wingspan is 40-60 millimeters, but as a result of many years of cultivation, butterflies have lost the ability to fly. The mouth apparatus is not developed because the adult does not feed. Only the larvae differ in an enviable appetite. They are fed with mulberry leaves. When feeding on 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, to which the silkworm belongs, are found in nature only in the Far East.

Silkworm caterpillars hatch from eggs, the laying of which is covered with a dense shell and is called grena. In sericulture farms, grena is placed in special incubators, where the necessary 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.

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

The caterpillar, ready for pupation, ceases to feed, and then wood rods are placed next to it, to which it immediately passes. Holding on to one of the rods with its abdominal legs, the caterpillar throws its head to the right, then back, then to the left and applies its lower lip with a "silk" tubercle to various places rod.

Caterpillars are fed with mulberry leaves.

Soon a rather dense network of silk thread is formed 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 silk cradle and turns into a chrysalis there. After about 20 days, a butterfly emerges from the chrysalis. She softens the cocoon with her alkaline saliva and, helping herself with her legs, hardly gets out to start looking 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 cocoons are sent to the factory to obtain raw silk. One centner of such cocoons yields approximately nine kilograms of silk thread.

It is interesting that the caterpillars, from which males are later obtained, are more diligent workers, their cocoons are denser, which means that 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 her great product.

Olga Timokhova, Candidate of Biological Sciences

These butterflies are used by humans to obtain silk; in general, the silkworm is a very old inhabitant of our planet. Some argue that people began to use it as early as five thousand years BC.

Today, the worms of this butterfly are bred for silk, Interesting Facts that in China and Korea, silkworm cockles are used for food, they are fried and such a dish is considered exotic, and these larvae are also used in folk medicine.

In our world, the most important countries that produce silk (60 percent of the total market) are India and China, where silkworms live the most.

Today, people know much more about the production and types of silk than about the insect that gave us this magnificent silk thread. We will talk about this in this article. We will find out what the silkworm looks like, what it eats, how it is bred, as well as its breeding characteristics.

Appearance

Silkworms got their name from their diet. They recognize only one tree - this is mulberry, in scientific language this tree is called mulberry. Silkworm caterpillars eat day and night without stopping. Therefore, some farm owners get inconvenienced if the tree is occupied by caterpillars of this breed. In the silk industry, the mulberry tree is specially grown to provide food for silkworms.

This insect goes through a standard development process, which can be seen in the video. Like all insects, the wild silkworm goes through four life cycles, namely:

• the formation of an egg (larva);
• the appearance of a caterpillar;
• pupa formation (silkworm cocoons);
• butterfly.

The butterfly is quite large. The wingspan is about 60 millimeters. The main characteristics of the appearance include the following indicators:

• the color is white with dirty spots;
• brown clear dressings on the wings;
• the front part of the wing is notched;
• males have comb whiskers, while females have this effect weakly expressed;

Outwardly, the wild silkworm is very beautiful. In the photo and video you can see how this breed of butterflies looks in life.

To date, this species practically does not fly, due to the content in unnatural conditions. There are also interesting facts that state that these insects do not eat when they become butterflies. This breed has obvious distinctive features from all other species. The fact is that for many centuries, a man kept a silkworm at home and therefore, today these butterflies cannot survive without his care and guardianship. For example, caterpillars will not look for food, even if they are very hungry, they will wait for a person to feed them. To date, scientists cannot give an exact answer about the origin of this species.

In modern sericulture, there are many varieties of silkworms. Most often, hybrid individuals are used. In general, this breed can be divided into two types:

• the first is monovoltine, such a species can give offspring no more than once a year;
• the second is polyvoltine, which produces larvae several times a year.

Hybrids are different outward signs, which include:

• wing color;
• body shape;
• the dimensions that characterize the pupa;
• shapes and sizes of butterflies;
• the size and color of the caterpillars (there is a breed of silkworm with striped caterpillars or one-color ones).

How all possible types of silkworms look can be seen in the photo or video.

The indicators of silkworm productivity include the following characteristics:

• the amount of output of dry cocoons and their total yield;
• how much cocoon shells can unwind;
• silk output;
• technical properties and quality of the resulting silk.

What are the characteristics of silkworm eggs?

In the scientific field, silkworm eggs are called grena. Features are as follows:

• oval shape;
• slightly flattened sides;
• elastic and translucent shell.

The size of the egg is incredibly small, in one gram there can be up to two thousand eggs. As soon as the butterflies have laid grena, it has a light yellow or milky color, and over time the color of the eggs gradually changes, at first turning a little pink and finally becoming dark purple. And when the color of the eggs does not change, this indicates that their vitality has been completely lost.

The ripening period of grena is long. Butterfly larvae are laid in July and August. Then they hibernate until spring. During this period, all metabolic processes in the egg slow down significantly. This is necessary so that the grena can transfer low temperatures, and the appearance of caterpillars was regulated. For example, if in winter the eggs were at a temperature not lower than +15 degrees, then future caterpillars develop very poorly. This is due to the fact that they hatch very early, even before the mulberry leaves appear (this main source food for silkworms). Therefore, during this period, the eggs are placed in the refrigerator, where a constant temperature is observed. temperature regime from 0 to -2 degrees.

Life cycle of caterpillars

The appearance of caterpillars refers to the larval stages of development of silkworms. They used to be called silkworms, but based on scientific terms, this name is incorrect. To external characteristics caterpillars include the following indicators:

• the body has a slightly elongated shape;
• there is a head, abdomen and chest;
• there are horny appendages on the head;
• on the inside of the body there are three pairs of pectoral, and five abdominal legs;
• caterpillars have chitinous covers that perform protective function and at the same time are their muscles.

The external data of the caterpillars can be found in the photo, as well as see them life cycle on video.

Once a caterpillar hatches from an egg, it is very small, weighing only half a milligram. But with such a small size and weight, the body of the caterpillars has all the necessary biological processes for a full life, so they grow rapidly. In the body of a caterpillar there are very powerful jaws, esophagus, developed pharynx, intestines, circulatory and excretory system. Thanks to such a developed organism, all the food consumed is very well absorbed. Imagine that these babies have more than four thousand muscles, which is eight times more than humans. Acrobatic numbers that caterpillars can perform are associated with this.

The life cycle of a caterpillar lasts about forty days, during which time it increases in size by more than thirty times. Due to this intensity of growth, the shell with which the caterpillars are born becomes small, so they need to shed their old skin. This process is called molting. During this period, individuals stop feeding and find a place to molt. Tightly attaching their legs to the leaves, or holding on to a tree, they freeze. In the people, this period is called sleep. This spectacle can be seen in detail in the photo. Then the caterpillar, as it were, hatches again from the old skin. First, the head appears, which has increased several times in size, and then the rest of the body. During sleep, the caterpillars cannot be touched, otherwise they will not be able to throw off the old cover, as a result of which they die.

For all your life span caterpillars go through the process of molting four times. And each time they have a different color. In the photo and video you can see the colors of the caterpillars.

The main part of the caterpillar's body for humans is the silk gland. This organ is best developed, thanks to artificial content for many centuries. In this organ, the silk we need is formed.

Final stage of development: silkworm chrysalis

Silkworm cocoons are formed for a short time (you can see them in the photo) This is an intermediate stage of development. The caterpillar forms a chrysalis around itself and stays there until it turns into a butterfly. Such silkworm cocoons are the most valuable for humans. Many amazing processes take place inside the cocoon, the caterpillar goes through the stage of the last molt and turns into a chrysalis, and then it becomes a butterfly.

The appearance of a butterfly and its departure can be easily determined. The day before the emergence of cocoons begin to move. If you lean against the cocoon at this time, you can hear a small noise, like tapping. This butterfly sheds its pupa skin. Interestingly, butterflies appear strictly at the allotted time. This is the period from five to six in the morning.

In order to get out of the cocoon, the mucous membranes of the butterfly secrete a specialized glue that splits the cocoon and makes it possible to fly out (newborn butterflies can be seen in the photo).

Butterflies live very little, no more than 18-20 days, but there are also centenarians who can reach the age of 25-30 days. The jaws and mouth of butterflies are undeveloped, so they cannot eat. During this short life span, their main purpose is to mate and lay eggs. One female can lay more than one thousand eggs per clutch. The laying process does not stop, even if the female does not have a head, because there are several nervous systems. In order to provide future offspring with good survival, females very strongly attach grena to the surface of a leaf or tree. That's all! This is where the life cycle of silkworms ends.

Then the process begins again, and goes through all the above stages again, supplying humanity with a silk thread.