Silkworm ants just hatched from eggs are called "ant silkworms". Their bodies are covered with fine hairs, and after about two days, their hairs will not be obvious.
Second, the silkworm baby has grown up.
Silkworm babies feed on mulberry leaves Keep eating mulberry leaves, the body turns white, and after a while it begins to peel off. When peeling for a day or so, it's like sleeping without eating. This is called "hibernation".
Third, silkworm babies spin silk.
Once peeled off, it is a second-instar larva. If she peels her skin once, she will be one year older, and * * * will have to peel her skin four times before she becomes a fifth instar larva and begins to spin silk and cocoon.
Fourth, the silkworm baby festival cocoons.
Five-year-old larvae need two days and two nights to form cocoons, in which they shed their skin for the last time and become pupae.
Fifth, the silkworm baby emerges from the cocoon.
About ten days later, it appeared in the form of a silkworm moth and came out of the cocoon. After the cocoon comes out, the female moth's tail will emit a smell to lure the male moth to mate. After mating, the male will die. It takes a female moth about one night to lay about 500 eggs, and then she will die slowly.
The larval stage (larval stage) of silkworm is the feeding and growth stage of silkworm. Traditionally, the time from hatching to maturity is considered as the time passed by the larval stage. When larvae grow to a certain extent, they need to shed their old skin and grow wider new skin before they can continue to eat and grow. This process is called sleep. Generally, silkworm breeds need to molt in the larval stage and enter the fifth instar, and then eat mulberry for 5-8 days to mature. The larval stage takes less than a month, but it grows very fast. When the fifth instar is extremely growing, its body length is 6 -7cm, which is 25 times higher than that of newly hatched ant silkworm, and its body width is 0.8cm, which is 20 times higher than that of ant silkworm. Its weight reaches 5-7 grams, which is about 10000 times higher than that of ant silkworm, and the weight of silk glands in the body is 160000 times higher than that of ant silkworm, from ant silkworm to mature stage. There are 10 abdominal segments, 3-6 abdominal segments, and 10 abdominal segment has a pair of abdominal feet (the abdominal feet of 10 abdominal segment are also called tail feet). Internodes mostly have internode membranes, which can make silkworms stretch. Silkworms that have just hatched from eggs are brown or reddish-brown, small in size and named after ants. The body length of the ant silkworm is about 2.5 mm, and the body width is about 0.5 mm. The weight of 2000-2300 ant silkworms is only 1 g, which is traditionally called the number of ants per gram. 2-3 hours after hatching, ants can be collected and fed to mulberry, and silkworm rearing can be started. If necessary, the silkworm can also be refrigerated at 5- 10℃ for 1-2d, which will affect the subsequent growth and development. Silkworm is also called silkworm. The silkworm that ants hatch to the first sensation is 1 year old, the silkworm from the first sensation to the second sensation is called the second, and the silkworm from the second sensation to the third sensation is called the third. In production, the silkworm of 1-3 years old is generally called a young silkworm or a young silkworm. Raise the temperature and humidity appropriately in the suitable temperature and humidity range in the young silkworm stage, and give the soft ripe mulberry leaves with high water content in protein for intensive feeding. The average 1 year-old silkworm is 15.95 times higher than the ant silkworm, and its body area is 5. 1 1 times higher. Compared with 1 instar silkworm, the body weight and body area of 2nd instar silkworm increased by 106.38 times, 29 times, 6.67 times and 5.67 times respectively. The body weight and body area of the third instar silkworm increased by 555.32 times, 88.32 times, 5.08 times and 5.67 times respectively. The silkworm from the third to the fourth sleep is called the fourth instar silkworm, and the silkworm after the fourth sleep is also called the fifth instar silkworm. Traditionally, 4-5 year old silkworms are called strong silkworms or big silkworms. In the big silkworm stage, the body eats a lot of mulberries and the chain is closed to ensure a good satiety of mulberries. Generally, the weight of the 4th instar silkworm is 2553.32 times higher than that of the ant silkworm, the face height is 23.86 times, the weight is 4.72 times higher than that of the 3rd instar silkworm, and the body area is 2.62 times higher. The body weight and body area of the 5th instar silkworm increased by 10425.53 times, 520 times, 4.08 times and 2.24 times respectively compared with that of the 4th instar silkworm. After the sleeping silkworm receives ants, the silkworm body grows rapidly because it feeds on mulberry leaves, and its body color changes gradually, from white to green, and then gradually becomes milky white and yellow. At this time, the appetite is reduced to stop eating completely, a small amount of silk is spun (commonly known as tripping), the abdomen is fixed on the silkworm seat, and the head and chest are lifted and no longer exercise. This state is called sleep. The silkworm at this time is a sleeping silkworm. From picking ants to ripening, you usually have to sleep four times. The process of sleeping is basically the same as that of sleeping silkworms, but the size of sleeping cocoons is different. Sleep time is called sleep. Under normal feeding conditions, the longest sleep time for the fourth time is about 2 days, the second time is only about 20 hours, and the first and third times are about 1 day. Silkworms that have been awake and asleep look motionless on the outside, but they are preparing to shed their skin on the inside. After the old skin was removed and replaced with new skin, the growth and development of silkworm entered a new era. Silkworms that have just molted are called silkworms. The newly hatched silkworm has tender mouthparts on its head and its appetite has not been aroused. Generally, it takes about half a day until their heads gradually turn from milky white to grayish brown before they can be fed to mulberries. In production, for the convenience of operation, 95% or even most of the same batch of dormant silkworms were collected and then fed to mulberries. At the end of the 5th instar, mature silkworms gradually showed mature characteristics: firstly, the discharged fecal particles changed from hard to soft, from dark green to leaf green; Loss of appetite, decreased mulberry consumption, empty digestive tract in front and translucent chest; Stop eating completely, the body becomes shorter and the abdomen tends to be transparent. Only 2-3 pieces of silkworm excrement can be seen vaguely at the tail. The head and chest of the silkworm body are raised, and the mouth is full of silk, swinging from side to side to find the place where the cocoon grows. At this time, the silkworm is called mature silkworm or suitable silkworm. In contrast, only silkworms with transparent breasts are called immature silkworms; A transparent silkworm that spits out a lot of silk thread is called an overripe silkworm. In group rearing, the most precocious silkworms are called primary silkworms, and the number is small; After half a day or 1 day, a large number of mature silkworms are called mature silkworms; A large number of silkworms that need to continue eating mulberries until the next day are called terminal silkworms. Age is generally calculated from ant collection to maturity. Sleepiness: The number of times a silkworm sleeps is a characteristic during the whole period from ant picking to mature spinning, which is called sleepiness. Sleepiness is a genetic feature. The existing silkworm variety resources include two-dormancy silkworm, three-dormancy silkworm, four-dormancy silkworm and five-dormancy silkworm. Sleepiness is controlled by the main gene of sleepiness located on chromosome 6, and also changes due to the influence of temperature, nutrition, light and other conditions. At present, the common word-bred silkworms in China belong to four-sleeping silkworms, and sometimes a small number of three-sleeping silkworms or five-sleeping silkworms appear in the actual feeding process. The varieties that often sleep have long larval stage, eat mulberry, have large cocoons and thick silk; The variety with less sleep is the opposite. Combining their advantages and disadvantages, it is generally considered that the four-dormancy silkworm variety is the most economical. Silkworm age is also called age. Usually, there are five instars of bivoltine silkworm breeds, the age from the first sleep is 1, the age after the second sleep, the age after the third sleep, the age after the fourth sleep and the fifth age after the fourth sleep. The length of an age is called age course, which includes mulberry eating time and sleep. The duration of the second instar is about 3 days, the fifth instar is about 6-8 days, 1 age and the third instar is about 3-4 days, and the fourth instar is about 4-5 days. The time when ants are collected and cocooned is called the whole age process. In an era, it can be divided into three stages: early stage, middle stage and late stage. Eating less mulberries in the early years is called short food period, eating more mulberries in the middle age is called total food period, and eating less in the later years is called short food period. When it is close to sleep, it is called sleep period or sleep period after mulberry falls asleep. Cocoon spinning and cocooning of mature silkworms can be divided into four processes: cocoon making net, cocoon making clothes, cocoon making layer and cocoon making lining. That is, after mature silkworms cocoon, they look for cocoon breeding places. They first glued the spun silk to the cocoon forming machine, and then connected the spun silk to the surrounding cocooned branches to form a cocoon forming bracket. At this time, the mature silkworm will remove all the residual feces in the body, and then continue to spin silk and form a cocoon into a web. The cocoon net does not have a cocoon shape, but a soft and messy cocoon silk layer as a support for further cocoon formation. After making the cocoon net, we continue to spit out messy silk loops, thicken the inner layer of the cocoon net, spin silk in an S-shaped way to make a cocoon coat, and the cocoon-shaped outline begins to appear. The silk in cocoon layer is slender and brittle, with irregular D arrangement and high sericin content. After the cocoon shell is formed, the cocoon cavity gradually becomes smaller, and the front and rear ends of the silkworm body are bent backwards into a "C" shape, and cocoon filaments are continuously ejected. The spinning mode is changed from S-shape to ∞ shape, and the direction is perpendicular to the silkworm body. Its long axis is 1 -2mm, and every 15 ∞ wire loop constitutes 1 group, which is called 65438. When 1 cocoon is completed, they move to the adjacent part and continue to make the second cocoon and the third cocoon, and many cocoons form a cocoon layer. Due to a large number of spinning and energy consumption in spinning, the body of silkworm is greatly reduced, the swinging speed of head and chest is slow, and there is no certain rhythm, and the ∝-shaped silk circle also loses its original uniformity. Spinning is messy, so the loose and soft cocoon silk layer is called pupa lining. Finally, after the pupa lining is done, the silkworm's head is up and the tail is down, and the residual silk in the body is spit out to form a soft cocoon top. At this point, the cocoon breeding process is over and the silkworm body enters the pupation stage. Cocoon formed by silkworm spinning is the raw material for reeling. The color of silkworm cocoons raised by hybrid silkworm eggs is white, oval or shallow waist, and its size is cocoon length × cocoon width, which is roughly 3-3.5 × 2-2.5 cm. Cocoon consists of cocoon layer, cocoon layer, pupa and molting. Cocoon layer is thick and hard, and the outer surface of cocoon is covered with a loose cocoon layer. There is a clear boundary between cocoon layer and cocoon layer. After peeling the cocoon shell, you can see the unique luster and wrinkles of the cocoon shell. Cut open the cocoon layer, which contains silkworm chrysalis and molting left by pupation. The weight of a cocoon is called the total cocoon quantity, the weight of a single cocoon layer is called the cocoon layer quantity, and the percentage of cocoon layer quantity to the total cocoon quantity is called the cocoon layer rate. Total cocoon weight 1.5-2.5g, cocoon layer weight about 0.3-0.55g, cocoon layer rate about 20%-25%. Silkworm pupae pupate about 4 days after cocoon winding. The pupa of silkworm chrysalis is rotating and divided into three parts: chest and abdomen. The head is very small, and there are a pair of compound eyes and a pair of tentacles on the ventral surface. The chest has three joints, three pairs of chest feet and two pairs of wings; The abdomen has 9 segments, the center of the eighth segment has an X-shaped line, and the center of the ninth segment has a brown spot, which are the body surface characteristics of male and female pupae respectively, and are often used as the basis for silkworm breeding to distinguish between male and female pupae. When the silkworm pupae just pupate, the color of the pupae is light yellow and tender. With the advance of pupa age, it gradually turns yellow, brown and brown, and the pupa skin gradually hardens. After about12-15 days, the pupa body softens again, and when the pupa skin is moderately shriveled and brown, it approaches the moth. Silkworm pupa is rich in nutrition, which can be used as food or feed, and can also be extracted from pupa oil and pupa protein as chemical or pharmaceutical raw materials. Silkworm moth (adult) Silkworm moth looks like a butterfly, but its two pairs of wings are very small and have lost the ability to fly, so the light will vibrate. The silkworm moth is covered with white scales, which can be clearly divided into three parts: head, chest and abdomen. The head is spherical, with protruding compound eyes on both sides, and a pair of comb-shaped tentacles in front of the summer eyes; There are three pectoral segments, l pairs of pectoral feet on the ventral surface and 2 pairs of wings on the dorsal surface. Some varieties have faint winglines. There is no abdominal foot in the abdomen, and the terminal body segment has evolved into an external genitalia. The male moth is large, slow to crawl and low in vibration frequency; Male moths are smaller, crawl faster and flap their wings frequently. Generally, mating lasts for 3-4 hours, and the female moth can give birth to fertilized eggs. In silkworm egg breeding, males should mate and discard after seed production; After laying eggs, the female moths are put into moth boxes according to regulations and sent to the female moths for particle inspection. Under natural conditions, the phenomenon of several generations of different colors in a year is called metamerism; Only one generation occurs in a year, that is, oviposition diapause. The second generation occurs, the first generation produces non-diapause eggs, and the second generation produces diapause eggs, which is called duality; There have been more than three generations called polyploid, some varieties produce diapause eggs in the last generation, and some varieties still produce non-diapause eggs in the last generation. Simple varieties have large cocoons and many silks, but they have long larval stage, eat mulberry and are weak in constitution. Multi-species have short larval stage, less mulberry consumption and strong physique, but less cocoon production; Bivoltine varieties are between the two, and their comprehensive economic benefits are better than those of bivoltine varieties, so at present, bivoltine silkworm varieties are mostly used in production. The hermaphroditic varieties with hermaphroditic or polygynous ancestry will change due to the influence of temperature, light, humidity and nutritional conditions, and should be raised according to the characteristics of the varieties and feeding precautions. Diapause, as a special developmental state, is the genetic feature of insects in the process of evolution. It is characterized by decreased metabolic level and suspended morphology. In fact, it is an instinctive reaction of insects to the periodic changes of environmental conditions, that is, they stop growing and developing at a certain development stage, and then continue to grow and develop when natural environmental conditions repeatedly reach their growth and development state. Diapause in egg stage of silkworm. Diapause began to pass through the low temperature in autumn and winter under natural conditions and could not be lifted until the following spring; Whether it is artificial method, low temperature storage at about 5℃, high temperature (46℃) hydrochloric acid treatment, or the combination of refrigeration and pickling, diapause can be relieved, diapause can be prevented, and even hatching can be promoted after diapause is relieved. Under the comprehensive action of temperature, light and nutrition, the diapause performance of bivoltine varieties will change.
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