The silkworm is a very interesting insect that has been known to man for a long time as source of silk... According to some data mentioned in the Chinese annals, the insect became known as early as 2600 BC. The process of obtaining silk for centuries in China has been a state secret, and silk has become one of the clear trade advantages.

Since the X-III century, other countries, including Spain, Italy, North African countries, have 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 for silk production, 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 silk production, and it is in these countries that the number of silkworms is maximal.

What does a silkworm look like?

This insect earned its unusual name thanks to the tree it feeds on. Mulberry - a tree also called mulberry, is the only food source for the silkworm.

Silkworm caterpillar eating wood day and night, which can even lead to his death if caterpillars occupy such trees on the farm. For the production of silk on an industrial scale, these trees are grown specifically to feed insects.

The silkworm goes through the following life cycles:

The silkworm butterfly is a large insect, and its wingspan reaches 6 centimeters. It has a white color with black spots, on the wings, in front of them, there are notches. Pronounced comb whiskers distinguish males from females, in whom this effect is almost invisible.

The butterfly has practically lost the ability to fly and modern individuals spend their entire life without climbing into the sky. This was the result of their very long keeping in unnatural living conditions. Moreover, according to the available facts, insects stop eating after becoming butterflies.

The silkworm acquired such strange features due to its keeping at home for many centuries. This led to the fact that now insect cannot survive without human care.

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

Hybrid silkworms can differ in many ways, such as:

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

The larvae or eggs of this butterfly in the scientific community are called green. They have an oval shape flattened from the sides, 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 are light milky or yellowish in color. Over time, changes occur, leading to the appearance of a pink tint 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 ripening period. He lays them off 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 effects of low winter temperatures.

If the grena hibernates at temperatures not lower than +15 degrees, then there is a risk of poor development in future caterpillars, therefore in winter it is necessary provide for grana optimal temperature conditions. Caterpillars appear earlier than the leaves have time to grow on the trees, therefore, the grenade is stored in refrigerators at temperatures from 0 to -2 degrees, throughout this period.

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

Immediately after birth, the caterpillar has a very small size and weight, not exceeding half of one milligram. Despite this size, 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, due to which all food consumed is very quickly and well absorbed. Each such small caterpillar has more than 8,000 muscles, which allows it to bend in intricate positions.

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 molting.

During molting, the silkworm caterpillar stops eating the leaves of trees and finds a separate place for itself, usually under the leaves, where, tightly attaching to them with its legs, it freezes for a certain period. I also call this period the caterpillar's sleep.

Over time, the head of the renewed caterpillar begins to break through from the old skin, then it comes out entirely. During this time, you must 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. During its life, the caterpillar sheds four times.

The intermediate stage in the transformation of the caterpillar into a butterfly is the 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 simple to determine - it begins to move literally a day before, and by ear you can distinguish light tapping inside. This knock appears because at this time the already ripe butterfly is trying to get rid of the caterpillar skin. It is curious that the time of birth of the silkworm butterfly is always the same - from five to six in the morning.

A special liquid resembling glue in consistency, which is secreted by butterflies, helps them to free themselves from the cocoon, splitting it.

The life span of a moth is limited to only twenty days, and sometimes they do not even live up to 18 days. In this case, you can meet long-livers among them who live for 25 or even 30 days.

Due to the fact that the jaws and mouth of butterflies are not sufficiently developed, they cannot feed. The main task of the butterfly is to continue the genus, and during their short life they manage to lay many eggs. For one clutch, a female silkworm can lay them up to a thousand pieces.

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




The mulberry silkworm, or silkworm caterpillar and butterfly, play an important economic role in the production of silk. The caterpillar feeds exclusively on mulberry leaves (mulberry tree). A closely related species, the wild silkworm, lives in East Asia: in the northern regions of China and the southern regions of the Primorsky Territory of Russia.


The silkworm is the only fully domesticated insect (and all the others in China have already been imported domesticated, not found in nature in the wild. Its females have even "forgotten how" to fly. The adult insect is a fat butterfly with whitish wings up to 6 cm. Beauveria bassiana, used in traditional Chinese medicine.


Silkworm caterpillars curl cocoons, the shells of which consist of a continuous silk thread with a length of m and up to 1500 m in the largest cocoons.


Caterpillars eat leaves without stopping, day and night, which is why they grow very quickly. A change in the color of the caterpillar's head to a darker one signals the beginning of molt. After the caterpillar has passed four molts, its body becomes slightly yellow, and the skin is denser, which indicates that the caterpillar begins to turn into a pupa, wrapping itself in a silk thread. Having passed the pupa stage, the butterfly gnaws through the cocoon and exits. But until this stage, the silkworm does not allow the cocoons to survive, they are kept for 22.5 hours at a temperature of about 100 ° C, which kills the caterpillar and simplifies the unwinding of the cocoon.






Silkworm in Art In 2004, the well-known 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 an album "Wild Grasses", on which a song called "Silkworm" sounds.

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

Egg

After mating, the female lays eggs (on average from 500 to 700 pieces), the so-called green. Grena has an oval (elliptical) shape, flattened from the sides, 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, intended for the passage of the seed thread. The size of the grène is about 1 mm long and 0.5 mm wide, but it varies considerably between breeds. In general, European, Asian Minor, Central Asian and Persian breeds give a larger green than Chinese and Japanese. Laying eggs can last up to three days. Diapause in the silkworm occurs at the egg stage. Diapausing eggs develop in the spring of the following year, and non-diapausing eggs in the same year.

Caterpillar

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

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

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

Silkworm- fairly well-known insect... This wild species was first seen in the Himalayas. The silkworm was domesticated for a very long time - from the third millennium BC.

He gained great fame in connection with the unique ability to create such cocoons, which are the raw materials for obtaining the most real silk. Silkworm taxonomy- belongs to the genus Silkworms, the true family of the same name. Silkworm is a representative detachment butterflies.

The main habitat of the insect is the regions of South-East Asia with a subtropical climate. It is also found in the Far East. Silkworms are bred in many regions, but the only requirement is that the mulberry should germinate in those places, since the silkworm larvae feed exclusively on it.

An adult is able to live only 12 days, during which it does not eat, since it does not even have a mouth. Surprisingly, silkworm butterfly can't even fly.

Pictured is a silkworm butterfly

As can be seen on photo, silkworm looks rather inconspicuous and looks like the most ordinary moth. Its wingspan is only 2 centimeters, and their color ranges from whitish to light gray. It has a pair of antennae, which are abundantly covered with bristles.

Silkworm lifestyle

The silkworm is a well-known garden pest, as its larvae are very voracious and can greatly harm garden plants. Getting rid of it is not so easy, and for gardeners, the appearance of this insect is a real disaster.

The life cycle of a silkworm includes 4 stages and is about two months. are inactive and live only to lay eggs. The female lays up to 700 eggs, which are oval in shape. The laying process can take up to three days.

Silkworm species

Nun silkworm living in the forest. Wings are black and white, antennae with long serrations. Reproduction takes place once a year, in summer. Caterpillars are very harmful to conifers, beech, oak and birch.

Nun silkworm butterfly

Ringed - is so named because of the characteristic form of the clutch - in the form of an egg. The clutch itself contains up to three hundred eggs. It is the main enemy of apple trees. The body of the butterfly is covered with light brown fluff. Ringed silkworm- it is his cocoons that are the main raw material for the production of silk.

Ringed Silkworm Butterfly

Pine silkworm- a pest of pines. The color of the wings is brownish, close to the color of pine bark. Quite large butterflies - females reach a wingspan of up to 9 centimeters, males are smaller.

Pine silkworm butterfly

Unpaired silkworm- the most dangerous pest, as it can infect up to 300 plant species. The name is due to the big difference between the female and the male in appearance.

Unpaired silkworm butterfly

Silkworm nutrition

It feeds mainly on mulberry leaves. The larvae are very voracious and grow very quickly. They can eat figs, bread and milk trees, ficuses and other trees of this species.

In captivity, lettuce leaves are sometimes eaten, but this has a bad effect on the health of the caterpillar, and therefore on the quality of the cocoon. At the moment, scientists are trying to create a special food for the silkworm.

Reproduction and life expectancy of the silkworm

Reproduction in this insect is the same as in most others. Meanwhile, as the female lays a clutch of eggs, and the first appearance of the caterpillars is about ten days.

With artificial breeding, a temperature of 23-25 ​​degrees is set for this. Silkworm caterpillar each subsequent day eats more and more food.

In the photo there are silkworm caterpillars

On the fifth day, the larva stops feeding, freezes, and the next day, when it crawls out of the old skin, it starts feeding again. Thus, four molts occur. At the end of development, the larva turns one month old. Under her lower jaw is the very papilla from which the silk thread stands out.

Silkworm thread despite its very small thickness, it can withstand up to 15 grams of load. Even newly born larvae can secrete it. Very often it is used as a rescue tool - in case of danger, the caterpillar can hang on it.

In the photo, the thread of the silkworm

At the end of the life cycle, the caterpillar eats little, and by the beginning of the cocoon construction, feeding completely stops. At this time, the gland that secretes the silk thread is so full that it always reaches for the caterpillar.

At the same time, the caterpillar displays restless behavior, trying to find a place to build a cocoon - a small branch. The cocoon is built within three to four days, and it takes up to a kilometer of silk thread.

There are cases when several caterpillars cocoon one cocoon on two or three or four individuals, but this rarely happens. Myself silkworm cocoon weighs about three grams, has a length of up to two centimeters, but some specimens reach a length of up to six centimeters.

Pictured is a silkworm cocoon

They vary slightly in shape - it can be round, oval, ovoid, or slightly flattened. The color of the cocoon is often white, but there are specimens whose color is close to golden, and even greenish.

The silkworm hatches after about three weeks. It has no jaw, so it makes a hole with saliva, which eats away at the cocoon. With artificial breeding, pupae are killed, otherwise the cocoon damaged after a butterfly is not suitable for obtaining a silk thread. In some countries, a moribund chrysalis is considered a delicacy.

Silkworm breeding is widespread. For this, mechanized farms are created for the production of yarn, from which a real silkworm silk.

Pictured is a silk thread farm

The clutch of eggs laid by the female is kept in the incubator until the larvae appear. As food, the larvae receive the usual food - mulberry leaves. All air parameters are controlled in the premises for the successful development of the larva.

Pupation takes place on special branches. When creating a cocoon, males secrete more silk thread, so silkworm breeders try to increase the number of males.

Silkworm (lat. Bombyx mori) - a nondescript little butterfly with dirty-white wings, which does not know how to fly at all. But it is thanks to her efforts that women of fashion from all over the world have been able to enjoy outfits made of fine soft fabric for more than 5000 years, the shine and colorful transfusion of which will fascinate at first sight.

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

There are monovoltine, bivoltine and polyvoltine silkworm breeds in the world. The former give only one generation per year, the latter two, and the third, several generations per year. An adult butterfly has a wingspan of 40-60 mm, it has an underdeveloped mouth apparatus, so it does not feed throughout its short life. The silkworm's wings are off-white in color; brownish bands are clearly visible on them.

Immediately after mating, the female lays eggs, the number of which varies from 500 to 700 pieces. The clutch of the silkworm (like all other members of the peacock-eyed family) is called green. It has an elliptical shape, flattened on the sides, and slightly more on one side than on 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 sizes of the grenas depend on the breed - in general, the Chinese and Japanese silkworms have less grenas than the European and Persian ones.

Silkworms (caterpillars) emerge from the egg, to which all the eyes of silk producers are riveted. They grow in size very quickly, molting four times during their life. The entire cycle of growth and development lasts from 26 to 32 days, depending on the conditions of detention: temperature, humidity, food quality, etc.

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

Ideally, the butterfly should emerge from the cocoon for 15-18 days, 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 pupae are used for food, in all other countries they are considered just "production waste".

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