Effective measures to control the gypsy moth. Silkworm - getting silk

Silkworms belong to the class of insects and are a great danger to the orchard. These voracious caterpillars are able to destroy a huge area of ​​​​plantations and thereby cause damage agriculture. In order not to suffer from these pests, you need to know how to deal with them correctly.

What does a gypsy moth look like

This insect is considered one of the most dangerous. It belongs to the Lepidoptera order. Sometimes it is also called the silk beetle, however, this is an erroneous name. Gypsy moth is a butterfly that leads mainly night image life. Its caterpillars damage the leaves, ovaries and buds of various fruit trees - pear, apple, plum, cherry and others. The name "unpaired" is due to the fact that adult females and males of this insect look very different from each other. Initially, they even thought that they belonged to a different order of insects.

Starting from mid-July, their eggs can be found on tree bark, stumps and even wooden fences. Each such masonry is covered with small villi and has a slightly yellowish color. The gypsy moth is very prolific. One clutch usually contains about 600 eggs.

The larvae that have just hatched from the eggs are also covered with fine fluff, so that they can be easily carried by the wind over short distances. Due to this gypsy moth can quickly spread throughout the garden.

He begins to spoil trees in the very first hours of his birth. Literally a month later, one detachment, consisting of hundreds of larvae, is able to spoil all the green spaces of the garden. Therefore, action must be taken very quickly.

What is dangerous ringed silkworm

This pest also belongs to the class of insects, the order of butterflies. Adults have a thick body covered with a light brown fluff. The females are larger. The ringed silkworm is smaller than the unpaired one. But at the same time, it is no less dangerous. Most of all, this insect loves the apple tree.

The name of this pest comes from its peculiarity of laying eggs in the form of a ring. Each such ring can contain up to 300 eggs. The presence of 5-6 such rings on a tree is already a serious danger for him.

Measures against caterpillars

These insects have enemies in wild nature. In addition to birds that love to feast on the caterpillars of these harmful butterflies, entomophages also pose a threat to them. These are living organisms belonging to the class of insects that can eat their own kind. The most common of these are ladybug, lacewing.

For caterpillars, the most dangerous among them is the ground beetle. This beetle eats the larvae of various butterflies. One female of such a beetle is able to eat up to six thousand larvae. Dead-eating beetles, as well as pestry beetles, are also considered active enemies of pests of fruit trees.

Many species of these beetles eat both butterfly larvae and pollen. Therefore, you can attract them to your garden by planting strong-smelling flowers in it, for example, marigolds, oregano, rosemary. It is best to plant flower beds around trees with them.

ground beetle

The photo shows a ground beetle - the main enemy of caterpillars. It is often mistaken for a harmful beetle, but on the contrary, it is excellent for pest control in the garden.

In addition, methods of dealing with garden pests can be attributed:

1. Regular inspection of all fruit trees in the garden for the presence of clutches. If they are found, they must be carefully removed from the bark of trees with a knife. Then burn or bury deep. Twigs with egg-laying are better to just cut off.
2. Spraying trees with insecticides before flowering.
3. Preventive washing of tree bark with special solutions.
4. Installation of special glue traps for already hatched caterpillars on the bark of trees.

Silkworm species that are safe for the garden

In addition to the two species of butterflies considered, there are also quite safe representatives of this family of insects that live in our area, which do not damage the garden, preferring wild trees, such as oak, pine or birch. These include:

1. Birch silkworm.
2. Oak silkworm.
3. Pine marching silkworm.

All of them belong to the same class and order as the previous butterflies. However, they do not live on garden trees. For example, the pine silkworm feeds on needles and pine sap. And although the caterpillars of this butterfly do not pose a danger to the garden, they can cause very serious damage to wild trees. They can eat the needles so that it seems that fire has walked through it.

The pine silkworm lays its eggs under the pine bark. The hatched eggs have a grayish color, merging with the bark of this tree. After some time, very voracious larvae appear from them, which feed on needles. One such caterpillar is able to eat up to 150 needles. For the winter, they crawl from the pine tree and hide under the moss. And in the middle of summer they turn into a butterfly.

Pine walking silkworm very dangerous pest pine plantations. Its caterpillars eat the needles so intensively that the damaged tree most often cannot recover and dies.

The main enemy of this pest in the wild are cuckoos. They happily eat the larvae of this insect.

The photo below shows a pine silkworm. Belongs to the class of insects. Butterfly Squad.

The birch silkworm prefers to settle on birches, eating buds and young shoots. He also loves willow and linden.

In the photo below you can see an adult of this insect on a birch branch.

The oak silkworm is not a pest. Unlike other representatives of this family, it is specially bred to produce natural silk. The oak silkworm is a very beautiful and elegant butterfly, which has recently begun to be grown in our latitudes. For this, wild trees are used - oak, birch, hornbeam or willow.

The oak silkworm is very large. Its wingspan can reach 12 cm. Two pairs of multi-colored eyes are symmetrically located along their edges, thanks to which the oak silkworm got its second name "peacock-eye".

This butterfly belongs to the family of true silkworms. Its common representatives are also Indian and mulberry silkworm.

The photo above shows an adult butterfly of this insect.

How to deal with silkworms suburban area, there are several ways folk remedies, insecticides, biological products, physical methods, biological, agrotechnical. are selected based on the personal preferences of the gardener, the degree of infection and the type of pest. You should always remember about preventive measures.

Description of the pest

The insect is ubiquitous, affects about 300 varieties of plants, prefers garden trees, oak, poplar. Only one generation grows per season, the larvae cause the greatest damage. for 50 days, actively feed on leaf juices, and then on the plates themselves.

On a note!

The butterfly lives only 10 days, does not eat anything, is busy reproducing offspring. Lays up to 300 eggs at one time. The years of young females, males begins at the end of June, the larvae remain in the eggs to overwinter. The female lays under the bark on the lower part of the tree, on old stumps, in the forest floor.

Eggs with hard shells can withstand frost, high humidity. Intensive development continues in early spring- in April. The mass revival of the pest is initially carried out on an oak tree. Larvae molt 5-6 times in 50 days, increase in size up to 75 mm. The caterpillar of the gypsy moth is brown in color, the body is covered with hairs, warts or processes.

At the final stage of development, pupation occurs without the formation of a cocoon. The larva wraps itself in cobwebs, holds on to leaves, twigs, and bark with its paws. Butterflies appear after a few days. The wingspan is up to 75 mm, the body is massive, covered with hairs, brown in color. In the photo you can clearly see what the silkworm looks like.

The fight against silkworms in the summer cottage should be comprehensive. Caterpillars in one season are able to destroy young garden trees, significantly reduce the yield on already formed plants.

• On young trees, caterpillars can be picked by hand and then destroyed. Egg clutches are scraped off the bark, trampled or burned.
• Attract to your area natural enemies gypsy moth - birds. Cuckoos, woodpeckers, finches, oriole, jays, and titmouse help to fight gypsy moth caterpillars. They build feeders, hang them on trees.
• In March, as soon as the snow melts, treat tree trunks with lime or apply adhesive belts. Such a barrier prevents the gypsy moth caterpillars from moving up to the crown, and does not allow pests to develop. For the manufacture of the belt, oil, resin, machine oil, adhesive tape, special preparations in the form of a gel consistency from harmful insects are used.
• At the beginning of the migration of caterpillars to the crown of trees - in April, even before bud break, an apple tree and other trees are treated with biological products or insecticidal agents. Used during flowering folk methods control of gypsy moth on apple, pear, plum and other garden plants.

You can get rid of the gypsy moth in your summer cottage in one season, if you make every effort to do this, combine several methods of exposure.

On a note!

A sign of tree infection is the presence of small holes on the leaves or significant deformations, as well as a cobweb.

Other types of silkworms are also common on the territory of Russia:

• marching pine;
• marching oak.

The caterpillars of all these species are silkworms and can cause skin irritation when picked with bare hands.

Biologicals

Fight the silkworm in the summer cottage where they grow fruit trees, expediently biological preparations. The active components of the products are bacteria that affect the work internal organs, systems or products of vital activity of microorganisms.

The drug starts the destructive process immediately, but the result can be seen within 7-10 days. The action lasts about 14 days. Heavy rains reduce the effectiveness of the remedy for gypsy moth. It is allowed to use at any stage of the growing season of the plant, except for the flowering period.

On a note!

Spray the apple tree from the gypsy moth for prevention should be 1 time per month, for the fight - twice in 30 days. Effective remedies- Fitoverm, Lepidocid, Spark bio, Entobacterin, Bitoxibacillin, Dendrobacilin.

Insecticides

Chemical methods of struggle allow you to get the desired result within a few days. A broad-spectrum poison destroys butterflies within the first 2 hours after spraying plants, caterpillars - up to 30 days. Initially, the poison enters the body by contact through the chitinous cover. It affects the work of the nervous system, causes muscle paralysis, death.

Sv 2 hours the active toxic substance enters the juice of the plant, silkworm caterpillars on the apple tree, other plants die during feeding. Mass death occurs within a few days.

When working with insecticides, safety measures must be observed - to protect Airways, mouth, eyes, skin. Otherwise, an allergic reaction occurs, intoxication of varying severity.

Gardeners call the best preparations Aktellik, Aktara, Karbofos, Fufnon. Poison is used in exceptional cases, if other methods of struggle do not help.

The effectiveness of folk remedies

You can fight gypsy moth caterpillars with decoctions of plants with a strong smell, laundry soap, spices, wood ash, table vinegar, ammonia.

On a note!

The soap base is needed in order to keep the active ingredients on the leaves, as well as to create a thin film, which makes it difficult to feed. Natural laundry soap is added to any folk remedy.

Spray the leaves:

• Table vinegar. For 1 liter of water 200 ml of the product.
• Ammonia. For 1 liter of water 10 ml of ammonia.
• Garlic tincture. For 1 cup of minced garlic 1000 ml of water.
• Wood ash. Add ash, soap to the water, mix thoroughly.

To achieve the desired result, you need to combine several methods of struggle, always remember about prevention. Conduct pest control all year round. It is much easier to cut the egg-laying on the trunk in autumn than to poison the larvae, to chase the caterpillars through the garden in the spring. It is necessary to get rid of pests with chemicals correctly so as not to harm yourself and the environment.

A sticky substance is released from a small tubercle under the lower lip of the caterpillar, 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! Butterfly has changed so much that now it's hard to tell who was her 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. 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. These were silkworm eggs, which the bride secretly took out of her homeland, hiding in her hair. Around the same time, the secret of silk became known to the 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. Along 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 dark brown larvae appear, covered with tufts of long hair.

Hatched caterpillars are transferred to a special aft 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, 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

Silkworm- very interesting insect, which has long been known to man as source of silk. According to some data mentioned in Chinese chronicles, the insect became known as early as 2600 BC. The process of obtaining silk for centuries in China was a state secret, and silk became one of the clear trade advantages.

Starting from the 13th century, other countries, including Spain, Italy, and North African countries, mastered the technology of silk production. In the 16th century, technology reached Russia.

Now the silkworm is actively bred in many countries, and in Korea and China it is used not only to obtain silk, but also for food. Exotic dishes that are prepared from it are distinguished by originality, and silkworm larvae are used for the needs of traditional medicine.

India and China are leaders in the production of silk, and it is in these countries that the number of silkworms is the largest.

What does a silkworm look like

Own unusual name this insect deserves thanks to the tree on which it feeds. Mulberry - a tree, which is also called mulberry, is the only source of food for the silkworm.

silkworm caterpillar eats a tree day and night, which can even lead to its death if the caterpillars occupy such trees on the farm. For the production of silk on an industrial scale, these trees are grown specifically for feeding insects.

The silkworm goes through the following life cycles:

The silkworm butterfly is a large insect, and its wingspan reaches 6 centimeters. She has white color with black spots, on the wings, in front of them, there are notches. Pronounced comb mustache distinguish males from females, in which such an effect is almost imperceptible.

The butterfly has practically lost the ability to fly, and modern individuals spend their entire lives without rising into the sky. This led to their very long content in unnatural living conditions. Moreover, according to available facts, insects stop eating after turning into butterflies.

Such strange features silkworm acquired because of keeping it at home for many centuries. This has led to now the insect cannot survive without human care.

The silkworm over the years of its breeding has managed to be reborn into two main species: monovoltine and polyvoltine. The first species lays larvae once a year, and the second - up to several times a year.

Hybrid silkworm individuals can have many differences in terms of such traits as:

• body shape;
• wing color;
• dimensions and general shape of the butterfly;
• pupa dimensions;
• color and shape of caterpillars.

The larvae or eggs of this butterfly in the scientific community are called Grena. They have an oval shape flattened laterally, with elastic transparent film. The dimensions of one egg are so small that for one gram of weight their number can reach two thousand pieces.

Immediately after the butterfly lays eggs, they have a light milky color or yellowish color. As time passes, changes occur, leading to the appearance of a pink hue in the larvae, and then to a complete change in color to purple. If the color of the eggs does not change over time, then the larvae have died.

Silkworm eggs have a fairly long maturation period. He lays them in the summer months: in July and August, and then they hibernate until spring. The processes taking place in them at this time slow down significantly in order to survive the impact of low winter temperatures.

If grena hibernates at temperatures not lower than +15 degrees, then there is a risk poor development in future caterpillars, so in winter period need provide for grena optimal temperature regime. Caterpillars appear before the leaves have time to grow on the trees, so grena is stored in refrigeration units at a temperature of 0 to -2 degrees throughout this period.

The caterpillars of this butterfly are also called silkworms, which cannot be considered a scientific name. Externally, silkworm caterpillars look like this:

Immediately after birth, the caterpillar has a very small size and weight, not exceeding half a milligram. Despite such dimensions, all biological processes in the caterpillar proceed normally, and it begins to actively develop and grow.

The caterpillar has very developed jaws, pharynx and esophagus, so that all food consumed is very quickly and well absorbed. Each such small caterpillar has over 8,000 muscles, which allows it to bend in intricate poses.

In forty days, the caterpillar grows to more than thirty times its original dimensions. During the growth period, she sheds her skin, which for natural reasons becomes small for her. This is called a molt.

During molting, the silkworm caterpillar stops eating the leaves of trees and finds itself separate place, usually under the leaves, where tightly attached to them with legs, it freezes for a certain period. This period is also called the sleep of the caterpillar.

With the advent of time, the head of the renewed caterpillar begins to break through from the old skin, then it comes out all in its entirety. At this time, you can not touch them. This can lead to the fact that the caterpillar simply does not have time to throw off the old skin and die. A caterpillar molts four times in its life.

An intermediate stage in the transformation of a caterpillar into a butterfly is a cocoon. Caterpillar creates a cocoon around itself and inside it turns into a butterfly. These cocoons are of the greatest interest to humans.

The moment when a butterfly should be born and leave its cocoon is very easy to determine - it starts to move literally a day before, and you can hear light tapping inside. This knock appears because at this time the already mature butterfly is trying to free itself from the skin of the caterpillar. It is curious that the time of the appearance of the silkworm butterfly into the world is always the same - from five to six in the morning.

A special glue-like liquid secreted by butterflies helps them break free from the cocoon.

The life of a moth is limited to only twenty days, and sometimes they do not even live up to 18 days. At the same time, it is possible meet among them centenarians who live for 25 and even 30 days.

Due to the fact that the jaws and mouth of butterflies do not have sufficient development, they cannot eat. The main task of the butterfly is to continue the genus and for its short life they have time to lay many eggs. In one laying, the female silkworm can lay up to a thousand of them.

It is noteworthy that even if the insect loses its head, egg laying process will not be interrupted. The body of a butterfly has several nervous systems which allows her long time continue laying and live, even in the absence of such a significant part of the body as the head.

A silkworm is called a silkworm caterpillar. He is from the family of true silkworms, which has about a hundred species. Their caterpillars weave a cocoon from silk: “the transformation of a chrysalis into a butterfly takes place in it. Some have so much silk in a cocoon that, skillfully unwinding it, you can get threads suitable for making fabrics. other silkworms (philosamia, telea).The best silk, however, gives the silkworm.This butterfly is a real pet, it is completely dependent on humans.Not like bees, which can live perfectly without people in the wild.

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

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

Different forms of silkworm cocoons. Below are caterpillars, commonly referred to as silkworms.

When, how long ago did they start breeding silkworms? The legend tells: 3400 years ago, a certain Fu Gi made musical instruments with strings from silk threads. But the real cultivation of the silkworm and the constant use of its silk for the production of fabrics began later: about 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 this significant event was celebrated annually with ritual holidays).

At first, only empresses and women of high rank were engaged in the production of silk. They kept the secrets of this business in secret.

“For more than 20 centuries, the Chinese jealously guarded the monopoly of silk and protected it with laws that punished by death or torture anyone who sought to take abroad the egg of a 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 a secret. This is what happened with sericulture. Whether it was true or genda, ancient texts say that in the 4th century AD, a Chinese princess brought her husband, the ruler of Bukhara, an invaluable marriage gift - silkworm eggs. She hid them in her intricate 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 seeds of a mulberry tree in hollow staffs, 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, the sericulture started here withered and only in the 8th century flourished again in the vast territory occupied by the Arabs, from Central Asia to Spain.

“The 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 (mulberry). The lack of cold-resistant mulberry varieties hinders the advancement of sericulture further north” (Professor F.N. Pravdin).

The leaves of this tree are eaten by silkworms with a loud crunch, which Pasteur compared to "the sound of rain falling on the trees during a thunderstorm." This is when there are a lot of worms and they all eat. And by 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 everyone eats and eats - they eat as much greenery in a day as they themselves weigh.

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

The silkworm, strictly speaking, eats only the leaves of the mulberry tree. We tried to feed him with other plants: blackberry leaves, for example, or lettuce. He ate them, but grew worse, and the cocoons were not the first grade.

So, eating at first the soft parts of the leaves, and then, when it matures, the veins, even the petioles, the silkworm grows rapidly. In the first days, it doubles its weight every day, and during its entire larval life it increases 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 calmly again and later weaves a cocoon. But in general, he is warm-hearted. The most favorable temperature for him is 20-25 degrees. Then it grows rapidly: its larval life, if there is enough food, is 30-35 days. When it is colder (15 degrees) - 50 days. It is possible in 14 days to make him complete all the processes necessary for the caterpillar to grow and prepare for transformation, if you feed it abundantly and keep it at 45 degrees Celsius.

10 days after the last, fourth molt, the appetite of the worm is no longer the same as before. Soon he stops eating altogether and starts crawling restlessly around. He now has a noticeable desire to climb higher: he crawls up the branches, and if there are none, along the walls of the cage or room. By this time, silk growers put branches vertically on shelves - fodder shelves, on which mulberry leaves still lay and where worms have lived all this time. Worms crawl on the branches. Some, as soon as they find a suitable place (somewhere in the fork of the boughs), begin to weave a cocoon. Others wander for another two days.

At this time, their silk-spinning organ secretes an already sticky thread. Having settled down on a branch, the worm, ^ quickly moving its head from side to side, stretches around itself chaotic threads of the web. They are called flakes. Inside this silk frame, soon, after a few hours, the oval outlines of the future cocoon are already visible. You can also see how the worm is busy inside it. But a day after the start of weaving, the walls of the cocoon are already so dense that the worm is not visible behind them. Another day or two, and the cocoon will be ready.

All the material that went into it consists of one continuous thread from 300 to 1500 meters long (depending on the race, that is, the breed, of the worm). The thread is double, under a microscope it looks like a ribbon, divided in the middle by a groove. Double - because the worm has two silk-producing glands (together they occupy 2 / s of the entire volume of the worm). The anterior parts of the glands are connected together in the mentioned silk papilla, j

The silk thread is extremely thin - 0.022-0.040 millimeters in diameter. But it is strong: it can withstand 15 grams without tearing.

Some worms (the so-called "carpet-makers") do not make cocoons, they crawl, crawl and line the surface of the aft shelves with silk, like a carpet. They turn into butterflies in a naked, not cocooned chrysalis. Others, joining in twos, weave a common cocoon. Sometimes three or four worms hide in one large (up to seven centimeters) cocoon, separated (or not) by partitions. But these are all deviations from the norm, and the norm is a spherical, oval (with or without an interception in the middle part) or a conical cocoon with the only worm in it that turns into a chrysalis. The color of the cocoon, depending on the race of the worm, is silver or golden, pinkish, greenish, bluish ... Its weight is 1-4 grams (with a chrysalis). Length - 2.5-6 centimeters.

The cocoons from which the males emerge contain more silk. The Soviet researcher B. L. Astaurov, using X-ray irradiation and other methods, managed to ensure that only males developed in cocoons: thereby, the production of silk increased significantly.

Having curled the cocoon, the worm loses its mobility, freezes inside its silk case, shrinks, loses weight and then turns into a chrysalis.

And the chrysalis after 20 days turns into a butterfly. How will she get out of her prison? Her goiter is filled with alkaline saliva, drop by drop the butterfly drops this saliva onto the inner wall of the cocoon: the silk softens, the threads unstick. The butterfly presses its head against the softened wall, breaks through it, vigorously scratching its legs, pushes the silk threads apart, enlarging the hole, and goes out. The wet creature that appeared still bears little resemblance to a butterfly, folded like a parachute assembly, its wings resemble stumps. Soon the air fills the trachea of ​​the butterfly, penetrates the wings, and they straighten out. However, some butterflies remain with unspread wings until the end of their days. But even those whose wings are quite normal cannot, alas, fly. Forgotten for a long time of life, surrounded by the worries of man. They only flutter their wings, which are too weak to lift a butterfly into the air. A butterfly thrown from a height can stay in the air for a few seconds, but then it still falls to the ground. And in general, she is not inclined to bother herself with unnecessary movements, a homebody even more than a caterpillar: she does not make any attempts to leave even from an open box or crate. Moreover, planted on the palm, it will sit on it, only sluggishly moving a few steps and moving its antennae.

Neither sugar syrup, nor nectar, nor honey will tempt her, because her mouth has been closed forever since she excreted drops of alkaline saliva: 12 (on average) days of life, the butterfly does not eat anything.

From the passive state in which he resides, the male butterfly emerges only when a female is approached to him or he stumbles upon her. Here he is excited, circling around her, moving his legs, and all the time flapping his wings.

Then, a few hours after this meeting (by the way, a very long one), the female begins to lay eggs. Slowly moving, it sticks them one by one to the surface on which it moves. The eggs are located close to each other in a space of several square centimeters. 400-800 eggs are laid in 5-6 days. Silkworm eggs are called grena. In winter, they are kept at low temperatures. In the spring, when the leaves on the mulberry tree begin to bloom, grena is gradually revived: it is first kept at a temperature of 12 degrees, then in special incubators at 23-25 ​​degrees Celsius.

After a few days, small worms come out almost simultaneously from all the eggs and crawl along the leaves laid out on racks in the wormhole - this is the name of the room in which silkworms are bred. It should be well ventilated and heated to 24-25 degrees.

In conclusion, I will give curious figures: 30 thousand worms can be bred from 25 grams of grena, before curling cocoons they will need (along with waste) up to 1.2 tons of leaves. They will give 63 kilograms of cocoons, of which (after processing with hot steam and unwinding on machines) you can get an average of 5.7 kilograms of raw silk.