Silkworm. The silkworm (lat. Bombyx mori) is the only domesticated insect. Grena stage - laying eggs

People know a lot about the merits of silk, but few people are familiar with the "creator" who gave the world this miracle. Meet the silk caterpillar. For 5,000 years, this small, humble insect has been spinning silk thread.

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

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

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

• Larva.
• Caterpillar.
• A chrysalis in a silk cocoon.
• Butterfly.

As soon as the head of the caterpillar darkens, the lenok process will begin. Usually the insect sheds its skin four times, the body becomes yellow, the skin acquires density. So caterpillar, moves on new stage, becomes a chrysalis, which is in a silk cocoon. IN natural conditions the butterfly gnaws a hole in the cocoon and shaves itself out of it. But in sericulture, the process proceeds according to a different scenario. Manufacturers do not allow silkworm cocoons to “ripen” until last stage. Within two hours under the influence high temperature (100 degrees), the caterpillar then dies.

Appearance of a wild silkworm

Butterfly with big wings. Domesticated silkworms are not very attractive (the color is white with dirty spots). It is fundamentally different from the "home relatives" is very beautiful butterfly with bright large wings. Until now, scientists cannot classify this species, where and when it appeared.

In modern sericulture, hybrid individuals are used.

1. Monovoltine, produces offspring once a year.
2. Polyvoltine, gives offspring several times a year.

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

Useful properties of silk thread

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

It would take a ton of mulberry leaves to feed thirty thousand caterpillars, enough for the insects to weave five kilograms of silk thread. The usual production rate of five thousand caterpillars yields one kilogram of silk thread.

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

Silkworm saliva contains sericin, a substance that protects silk from pests such as moths and mites. The caterpillar secretes a viscous substance of sloping origin (silk glue) from which it spins a silk thread. Despite the fact that most of this substance is lost during the manufacture of silk fabric, even the little that remains in the silk fibers can save the fabric from the appearance of dust mites.


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

Silkworms and cosmetics

Interesting fact. Few people know that a silk cocoon is an invaluable product; it is not destroyed even after all silk threads are removed. Empty cocoons are used in cosmetology. Masks and lotions are prepared from them not only in professional circles, but also at home.

silkworm gourmet food

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


In Korea, they eat half-cooked silkworms, for which they are lightly fried. This is a good source of protein.

Dried caterpillars are commonly used in traditional Chinese and Tibetan medicine. The most interesting thing is that mold fungi are added to the “medicine”. Here is a useful silkworm.

What do good intentions lead to?

Few people know that the gypsy moth, which is the main pest of the US forestry industry, spread as a result of an unsuccessful experiment. As they say, I wanted the best, but the following came out.

Silk caterpillar in 30 days increases in weight by 10 thousand times

People know a lot about the merits of silk, but few people are familiar with the "creator" who gave the world this miracle. Meet the silkworm. For 5,000 years, this small, humble insect has been spinning silk thread.

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

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

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

• Larva.
• Caterpillar.
• A chrysalis in a silk cocoon.
• Butterfly.

Extremely interesting breeding history such an insect as the silkworm.

The technology was developed a long time ago, in ancient China. The first mention of this production in Chinese chronicles dates back to 2600 BC, and silkworm cocoons found by archaeologists date back to 2000 BC. e. The Chinese elevated silk making to the status of a state secret, and for many centuries this was the country's clear priority.

The ancient Chinese philosopher Confucius retells the legend of how man first learned about the silk thread. Empress Xi-Ling-shi found a cocoon under a mulberry bush and mistook it for some wondrous fruit. But he accidentally fell out of her hands into a cup of tea. Trying to get it, the empress pulled out a silk thread. In gratitude for this accidental discovery, the Chinese elevated Xi-Ling-shi to the rank of a deity of the Celestial Empire. At first, only empresses and women from among their entourage were engaged in the production of silk.

The Chinese knew how to keep their secrets - any attempt to take out butterflies, caterpillars or silkworm eggs was punishable by death. But all secrets are revealed someday. This happened with the production of silk. First, some selfless Chinese princess in V. BC, having married the king of small Bukhara, she brought him a gift of silkworm eggs, hiding them in her hair. About 200 years later, in 552, two monks came to the emperor of Byzantium, Justinian, who offered to deliver silkworm eggs from distant China for a good reward. Justinian agreed. The monks went on a journey and returned the same year, bringing silkworm eggs in their hollow staffs. Justinian was fully aware of the importance of his purchase and ordered silkworms to be bred in the eastern regions of the empire by special decree. However, sericulture soon fell into decline and only after the Arab conquests flourished again in Asia Minor, and later in North Africa, in Spain. Much later, in the 13th century, Italy, countries began to breed such worms and produce silk fabric. North Africa, and in the 16th century - and Russia.

The "Great Silk Road" - a caravan road that in ancient times connected the West with the East and stretched through the mountains of Central and Central Asia - served the development of geography as a science and trade between ancient countries.

In the 20th century, silk had a serious rival - artificial and then synthetic chemical fibers. Many of them are stronger than silk, less wrinkled, more resistant to abrasion, but a person feels better in clothes made from natural silk.

Butterfly with big wings

What kind of insect is the silkworm?

The silkworm is not found today in wild nature and is bred in special factories to obtain a natural thread. An adult is a rather large insect - a light-colored butterfly, reaching 6 cm in length with a wingspan of up to 5-6 cm. various breeds this interesting butterfly engaged in breeders in many countries. After all, optimal adaptation to the characteristics of various localities is the basis for profitable production and maximizing income. The silkworm cannot live without human care, it is not able to survive in the wild. The silkworm caterpillar is not able to get food on its own, even if it is very hungry, it is the only Butterfly that cannot fly, which means that it is not capable of finishing food on its own.

Many silkworm breeds have been bred: monovoltine - they give one generation a year, polyvoltine - two, and there are species that give several broods a year. Despite its size, the silkworm butterfly does not fly, as it has long lost this ability. She lives only 12 days and during this time she does not even eat, having an undeveloped oral cavity.

Butterfly and ... Butterfly again

With the onset mating season silkworm breeders plant pairs of butterflies in separate bags. After mating, the female spends 3-4 days laying eggs in the amount of 300-800 pieces per grain, which has an oval shape with significantly varying sizes, which are directly dependent on the breed of the insect. The period of removal of the worm also depends on the species - it can be in the same year, or maybe in the next.

Caterpillar- the next stage in the development of the silkworm cocoon. The silkworm caterpillar hatches from eggs at a temperature of 23-25 ​​°C. In the factory, this happens in incubators at a certain humidity and temperature. The eggs develop within 8-10 days, then a brown small up to 3 mm long silkworm larva, pubescent with hairs, appears from the grena. Small caterpillars are placed in special trays and transferred to a well-ventilated warm room. These containers are a structure like a bookcase, consisting of several shelves, covered with a net and having a specific purpose - here the caterpillars constantly eat. They feed exclusively fresh leaves mulberry, and the proverb “appetite comes with eating” is absolutely accurate for determining the voracity of caterpillars. Their need for food grows exponentially, already on the second day they eat twice as much food as on the first. A silkworm in 30 days increases in weight by 10,000 times.

Molt. By the fifth day of life, the larva stops, freezes and begins to wait for its first molt. When the color of the head of the caterpillar darkens, it means that the molt has begun. She sleeps for about a day, clasping her legs around a leaf, then, with a sharp straightening, the skin bursts, releasing the caterpillar and giving it the opportunity to rest and again take up satisfying hunger. For the next four days, she absorbs the leaves with an enviable appetite, until the next molt comes.

caterpillar transformations For the entire period of development (about a month), the caterpillar molts four times. The last molt turns it into a rather large individual of a magnificent light pearl shade: the body length reaches 8 cm, the width is up to 1 cm, and the weight is 3-5 g with dense skin. A large head stands out on the body with two pairs of well-developed jaws, especially the upper ones, called "mandibles". But the most important quality that is important for the production of silk is the presence in an adult caterpillar of a tubercle under the lip, from which a special substance oozes, which hardens on contact with air and turns into a silk thread.

Formation of silk thread. This tubercle ends with two silk glands, which are long tubes with a middle part turned into a kind of reservoir in the body of the caterpillar, accumulating a sticky substance, which subsequently forms a silk thread. If necessary, the caterpillar releases a trickle of liquid through the hole under the lower lip, which solidifies and turns into a thin, but strong enough thread. The latter plays a big role in the life of an insect and is used, as a rule, as a safety rope, since at the slightest danger it hangs on it like a spider, not being afraid to fall. In an adult caterpillar, silk glands occupy 2/5 of the entire body weight.

Stages of building a cocoon. Having reached adulthood after the 4th molt, the caterpillar begins to lose its appetite and gradually stops eating. The silk secreting glands by this time are filled with liquid so that a long thread constantly stretches behind the larva. This means that the caterpillar is ready to pupate. She begins to look for a suitable place and finds it on cocoon rods, promptly placed by silkworm breeders along the side walls of the stern "shelves".

Having settled on a twig, the caterpillar begins to work intensively: it alternately turns its head, applying a tubercle with a hole for the silk gland to different places on the cocoon, thereby forming a very strong network of silk thread. It turns out a kind of frame for future construction. Then the caterpillar crawls to the center of its frame, holding itself in the air by means of threads, and begins to spin the actual cocoon.

Cocoon and pupation. Silkworm caterpillars use a continuous silk thread to curl their cocoons, the length of which is 300-900 meters, there were also large cocoons that were “wound” from 1500 meters of threads. When building a cocoon, the caterpillar turns its head very quickly, releasing up to 3 cm of thread on each turn. Its length to create the entire cocoon is from 0.8 to 1.5 km, and the time spent on it takes four or more days. Having finished work, the caterpillar falls asleep in a cocoon, turning into a chrysalis. The weight of the cocoon together with the chrysalis does not exceed 3-4 g. Silkworm cocoons are very diverse in size (from 1 to 6 cm), shape (round, oval, with bridges) and color (from snow-white to golden and purple). Experts have noticed that male silkworms are more diligent in terms of cocoon weaving. Their pupal dwellings are distinguished by the density of the winding of the thread and its length.

And again a butterfly. After three weeks, a butterfly emerges from the chrysalis, which needs to get out of the cocoon. This is difficult, since it is completely devoid of jaws that adorn the caterpillar. But wise nature solved this problem: the butterfly is equipped with a special gland that produces alkaline saliva, the use of which softens the wall of the cocoon and helps to release the newly formed butterfly. So the silkworm completes the circle of its own transformations.

However, industrial breeding of the silkworm interrupts the reproduction of butterflies. The bulk of the cocoons is used to produce raw silk. After all, this is a finished product, it remains only to unwind the cocoons on special machines, after killing the pupae and treating the cocoons with steam and high temperature water (100 degrees), and the cocoon unwinds very easily after that. So, the silkworm, whose breeding in industrial scale, probably never loses its relevance, - a magnificent example of a domesticated insect that brings a very considerable income.

It would take a ton of mulberry leaves to feed thirty thousand caterpillars, enough for the insects to weave five kilograms of silk thread. The usual production rate of five thousand caterpillars yields one kilogram of silk thread.

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

Useful properties of silk thread

Silkworm saliva contains sericin, a substance that protects silk from pests such as moths and mites. The caterpillar secretes a viscous substance of sloping origin (silk glue) from which it spins a silk thread. Despite the fact that most of this substance is lost during the manufacture of silk fabric, even the little that remains in the silk fibers can save the fabric from the appearance of dust mites.

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

Silkworms and cosmetics

Interesting fact. Few people know that a silk cocoon is an invaluable product; it is not destroyed even after all silk threads are removed. Empty cocoons are used in cosmetology. Masks and lotions are prepared from them not only in professional circles, but also at home.

silkworm gourmet food

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

In Korea, they eat half-cooked silkworms, for which they are lightly fried. This is a good source of protein.

Dried caterpillars are commonly used in traditional Chinese and Tibetan medicine. The most interesting thing is that mold fungi are added to the “medicine”.

What do good intentions lead to?

Few people know that the gypsy moth, which is the main pest of the US forestry industry, spread as a result of an unsuccessful experiment. As they say, I wanted the best, but the following came out.

At the end of the nineteenth century, a man came up with the idea to bring the new kind he planned to cross the silkworm and the gypsy moth. To get an insect that will be less "fastidious in food", but at the same time it must produce silk thread. For this purpose, a batch of gypsy moth cocoons was brought from Europe to America. The experiment is over complete failure. The scientist failed to cross these types of silkworms, but the gypsy moth is “comfortably” located in America and is now harming the forestry of the United States of America.

Only the facts

• Silk thread is very strong, able to withstand great pressure. Ropes made of silk are more efficient than ropes made of steel of the same thickness.
• It takes about 3,000 silkworm cocoons to produce 1m of silk fabric.
• Almost 80% of the world's silk production belongs to China.

To create a silk thread sufficient to produce fabric for 1 dress, silkworms need to eat about 70 kg of leaves.

1 silkworm caterpillar, from its transformation into a chrysalis, eats mulberry leaves, which are 40 thousand times larger in mass than its weight.

1 silkworm caterpillar in 4 weeks from the moment of its birth increases in size by 25 times, its mass increases by 12 thousand times.

The speed at which the silkworm produces its thread can be 15 meters per minute.

The silkworm caterpillar weaves its cocoon in 3-4 days.





Here is a useful silkworm.

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13.06.2017

With the history of the silkworm, thanks to which such a wonderful fabric as natural silk (lat. Mulberry) is associated with a huge number of ancient fictions and legends.

This amazing quality material is produced by caterpillars, which, eating the leaves of the mulberry tree (for us, the name mulberry is more familiar), process them, creating a surprisingly thin and strong silk thread from which they weave their cocoons.

silkworm ( lat. bombyx mori) is a butterfly from the insect family " real silkworms", A " bombyx mori» translated from Latin literally means "death of a silkworm" or "dead silk". Such a tragic name is explained by the fact that a living butterfly is specifically not allowed to leave the cocoon, so the insect, suffocating, dies inside it (more on this sad fact a little later in the text).

Cocoons can be of various colors and shades, which depends primarily on the type of silkworm, but White color considered to be of the highest quality because it contains the highest percentage of silk protein.

Currently, silk production is most developed in China, Japan and India.

adult insect

It is assumed that the silkworm moth descended from its wild relative, which previously lived in mulberry thickets. ancient China. According to some historical data, the culture of creating silk originated about five thousand years ago, and during this time the insect was completely domesticated and even lost the ability to fly (during the mating period, only males insect).

The silkworm butterfly is a rather large insect with a wingspan of up to six centimeters. It is noteworthy that immediately before pupation, it can increase in height up to nine (!) Centimeters.

Egg

Having hatched from a cocoon, an adult female mates with a male, after which she lays eggs for four to six days, covering them with a dense shell called grenay. During this period, the moth does not eat anything, since its oral apparatus is underdeveloped.

Silkworm embryos are small and have a light yellow or milky color. Having laid from three hundred to six hundred eggs (sometimes the number of eggs in an oviposition can reach eight hundred), the silkworm butterfly dies.

Larva

After about a week, a small dark brown larva emerges from the embryo (the silkworm caterpillar is often called " silkworm”) about two to three millimeters long.

From birth, the larva has an excellent appetite, so it feeds around the clock, eating juicy mulberry leaves with pleasure.

Silkworm caterpillars are very sensitive to temperature and humidity, they are not tolerant of pungent odors and cannot stand loud sounds, but if external conditions habitats are quite favorable, the larvae are rapidly gaining weight, day by day, increasing the consumption rate plant food. In the rooms where silkworms are grown, the monotonous work of many jaws is a continuous hum, as if a fine rain is drumming on a metal roof.

It is hard to imagine that these babies have more than four thousand muscles in their crumbled body, which is eight times (!) More than a person.

During the growing season, the silkworm larva goes through four stages or phases of maturation, and the first molt occurs already on the fifth day from the date of birth, while the caterpillar stops feeding, and firmly clinging to the leaf, hibernates for a day. Waking up, the caterpillar sharply straightens its body, which is why the old skin bursts and the grown insect, freed from its former clothes, with new force pounces on food.

After four molts, the body of the caterpillar increases in size by more than thirty (!) Times and their body acquires a yellowish tint.

chrysalis

In total, the silkworm caterpillar grows and develops for about a month, and immediately before pupation, the larva loses all interest in food.

Under the lower lip of the insect there are special glands capable of producing a silky gelatinous substance, which, when hardened, turns into a thin silk thread.

Silkworm thread is ninety percent protein. In addition, it contains salts, fats, wax and a sticky substance. sericin, which prevents the threads from disintegrating tightly fastening them to each other.

When the time comes, the caterpillar fixes its body on a strong base and begins to form a frame around itself in the form of a fine mesh, and then weaves the cocoon itself, winding the thread around itself in a “figure eight”.

After three or four days, the cocoon is completely ready, and the total length of the thread in the finished cocoon can reach from three hundred meters to one and a half (!) kilometers.

It is noteworthy that male silkworms make cocoons more scrupulously, so they are somewhat denser to the touch, and the length of the silk thread in the male cocoon is longer.

After about eight to nine days, the cocoons can be collected and spun to produce a thread of unique quality. If this process is late, then an adult insect will come out of it ( imago) in the form of a butterfly, which will damage the shell of the cocoon and the thread will eventually be torn.

As mentioned earlier, the butterfly has an underdeveloped mouth apparatus, therefore it is not able to gnaw through the shell of the cocoon and, in order to fly out, it secretes a special substance with saliva that dissolves the upper part of the cocoon, damaging the threads. To avoid this, butterflies are artificially killed right in their cocoons with the help of hot air, processing the pupae for two hours. This process kills the butterfly, so that the name of this insect species (" Death of the silkworm") is fully justified.

After the thread is unwound, the dead chrysalis is eaten (typically in China and Korea) because it is rich in protein and nutrients.

The process of creating silk thread

Currently, the silkworm is grown mainly artificially.

Cocoons are collected, sorted by color, size and prepared for subsequent unwinding, for which they are dipped in boiling water. This process is still done by hand, because the thread of the cocoon is very thin and requires special care to unwind it.

To create a raw thread, when unwinding, from three to ten silk threads are connected together, and all the same natural sericin helps to carefully fasten all the ends.

Raw silk is wound into yarn and sent to a weaving factory for further processing and production of a wonderful fabric highly valued throughout the world.

Legend has it that the first person who came up with the idea of ​​weaving silk thread was the legendary Chinese Empress Lei Zu (also known as Xi Lingshi), walking in a mulberry garden with a cup of hot tea, into which a silkworm cocoon suddenly fell. Trying to get it, the empress pulled a thin thread, which caused the cocoon to unwind.

Lei Zu convinced her husband (the legendary ruler of China, Huangdi or " yellow emperor"") to provide her with a grove of mulberry trees where she could breed caterpillars that produce cocoons. She is also credited with inventing a special spool that combines thin threads into one strong thread suitable for weaving, and inventing the silk loom.

In modern China, Lei Zu is an object of worship and bears the honorary title " Mother of the Silkworm».

Silkworm (lat. bombyx mori) is a nondescript little butterfly with off-white wings that can't fly at all. But it is thanks to her efforts that women of fashion all over the world have been able to enjoy outfits made of beautiful soft fabrics for more than 5000 years, the brilliance and colorful transfusion of which fascinate at first sight.

Silk has always been a valuable commodity. The ancient Chinese - the first manufacturers of silk fabric - kept their secret securely. For its disclosure, an immediate and terrible death penalty was due. They domesticated silkworms as early as 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 entire life. short life. The wings of the silkworm are off-white in color, brownish bandages are clearly visible on them.

Immediately after mating, the female lays eggs, the number of which varies from 500 to 700 pieces. The laying of a silkworm (like all other representatives of the peacock-eye family) is called grena. It has an elliptical shape, flattened on the sides, with one side slightly larger than the other. On a thin pole there is a recess with a tubercle and a hole in the center, which is necessary for the passage of the seed thread. The size of grena depends on the breed - in general, Chinese and Japanese silkworms have less grena than European and Persian ones.

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

Silkworms feed on the leaves of the mulberry tree (mulberry), so silk production is possible only in places where it grows. When the time of pupation comes, the caterpillar wraps itself in a cocoon, consisting of a continuous silk thread with a length of three hundred to one and a half thousand meters. Inside the cocoon, the caterpillar transforms into a chrysalis. In this case, the color of the cocoon can be very different: yellowish, greenish, pinkish or some other. True, only silkworms with white cocoons are bred for industrial needs.

Ideally, the butterfly should emerge from the cocoon on the 15-18th day, however, unfortunately, it is not destined to live up to 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 eaten, 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.

Silkworm- well known insect. The wild species of this species was first seen in the Himalayas. The silkworm has been 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 material for obtaining real silk itself. Systematics of the silkworm- belongs to the genus Silkworms of the real family of the same name. Silkworm is a representative detachment butterflies.

The main habitat of the insect is the regions of Southeast Asia with a subtropical climate. It also occurs on Far East. Silkworms are bred in many regions, but the only requirement is that mulberry must sprout in those places, since 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 unattractive and looks like the most common moth. Its wingspan is only 2 centimeters, and their color varies from whitish to light gray. It has a pair of antennae, which are abundantly covered with bristles.

Lifestyle of the silkworm

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.

Silkworm life cycle includes 4 stages and is about two months. sedentary 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.

Types of silkworm

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

Butterfly silkworm nun

Ringed - bears this name because of characteristic form masonry - 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 a light brown fluff. ringed silkworm- it is his cocoons that are the main raw material for the production of silk.

Butterfly ringed silkworm

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

Pine silkworm butterfly

gypsy moth - the most dangerous pest, as it can affect up to 300 plant species. The name is due to big difference female and male in appearance.

Gypsy moth butterfly

Nutrition of the silkworm

It feeds mainly on mulberry leaves. The larvae are very voracious and grow very quickly. They can eat figs, breadfruit and dairy 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. IN this moment scientists are trying to create a special food for the silkworm.

Reproduction and life span of the silkworm

Reproduction in this insect takes place in the same way as most others. Between the time the female lays her eggs and the first appearance of the caterpillars, about ten days pass.

At artificial breeding for this, the temperature is set to 23-25 ​​degrees. Silkworm caterpillar each subsequent day eats more and more food.

Pictured are silkworm caterpillars

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

silkworm thread, despite its very small thickness, can withstand up to 15 grams of cargo. It can be isolated even by newly born larvae. Very often it is used as a saving tool - in case of danger, the caterpillar can hang on it.

In the photo, a silkworm thread

At the end life cycle the caterpillar feeds little, and by the beginning of the construction of the cocoon, feeding stops completely. 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 exhibits 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 twist one cocoon for two, 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 in about three weeks. It does not have a jaw, so it makes a hole with saliva, which eats away at the cocoon. With artificial breeding, the pupae are killed, otherwise the cocoon damaged after the butterfly is not suitable for obtaining silk thread. In some countries, the slaughtered chrysalis is considered a delicacy.

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

Pictured is a silk thread farm

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

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