CATDOLL : CATDOLL: What are the four stages in the life of a silkworm? (What are the four stages in the life of a silkworm? Picture and drawing)

1. What are the four stages of a silkworm’s life?

The life cycle of a silkworm consists of four stages: egg, larva, pupa and adult.

Silkworm eggs:

Silkworms reproduce by laying eggs. Silkworm eggs look like fine sesame seeds, about 1 mm wide and 0.5 mm thick. A female moth can lay 400 to 500 silkworm eggs. 1700 to 2000 silkworm eggs weigh about 1 gram and have a diameter of 0.2 cm. The color of silkworm eggs is light yellow or yellow when they are first laid, and changes to light red bean color or red bean color after 1 to 2 days, and then turns to gray-green or purple after 3 to 4 days. It no longer changes and is called a fixed color.

The outer layer of the silkworm egg is a hard eggshell, and inside is yolk and serous membrane. The embryo in the fertilized egg continuously absorbs nutrients during the development process and gradually develops into a silkworm. It crawls out of the eggshell, and the eggshell becomes white or light yellow after it is empty.

The first instar is four to five days; the second instar is three to four days; the third instar is four days; the fourth instar is six days; the fifth instar is seven to nine days; the pupal stage is fourteen to eighteen days; and the moth stage is three to five days.

larva:

When the silkworm hatches from the egg, its body is brown or black, very small, and covered with fine hairs, and it looks a bit like an ant, so it is called ant silkworm. The ant silkworm is about 2 mm long and 0.5 mm wide. After it crawls out of the egg shell, it will eat mulberry leaves after 2 to 3 hours.

silkworm chrysalis:

After the silkworms spin cocoons on the cocoon nest, they will turn into pupae after about 4 days. The body shape of the silkworm pupa is like a spindle, with three body sections: head, thorax and abdomen. The head is very small, with compound eyes and antennae; the thorax has thoracic legs and wings; the bulging abdomen has 9 body segments. Professional workers can distinguish the sex of silkworms from the lines and brown dots on the abdomen of the silkworm pupa. When the silkworms first pupate, their body color is light yellow and the pupa body is tender and soft. Gradually, it will turn into yellow, yellow-brown or brown, and the pupa skin will also harden. After about 12 to 15 days, when the pupa body begins to soften again and the pupa skin is a little wrinkled and earthy brown, it will turn into a moth.

2. What is the complete version of the evolution process of silkworms?

The life of a silkworm goes through four stages: egg - larva - pupa - adult.

1. Incubation

The silkworms that have just hatched from the eggs are called ant silkworms. Their bodies are covered with fine hairs, which are no longer noticeable after about two days.

2. Grow Up

Silkworms live on mulberry leaves. After eating mulberry leaves continuously, their bodies turn white. After a period of time, they begin to shed their skin. Silkworms do not eat or move when they sleep. On the surface, they are sleeping, but in fact, they are shedding their old skin and replacing it with a new one to continue growing. Silkworms shed their skin four times during the entire breeding process. Each time they shed their skin, they do not eat or move. Try not to disturb them at this time, and do not throw them away thinking they are sick. Each silkworm hibernation period lasts about one day.

3. Spinning

After molting once, the larvae become the second instar. Each molt adds one year to the larvae's age, and they have to molt four times in total to become the fifth instar larvae before they begin to spin silk and make cocoons.

4. Cocooning

Generally, the silkworms start to spin cocoons around 25 days old. When the silkworms' backs are shiny, yellow and transparent, it means that they are ready to spin silk and spin cocoons. At this time, a cross-space should be provided for the silkworms to spin cocoons. It takes two days to spin a complete cocoon, and the silkworms complete the last molting in the cocoon and become pupae.

5. Breaking out of the cocoon

After about ten days, the female moth emerges from its cocoon and becomes a silkworm moth. After emerging from the cocoon, the female moth emits a scent from its tail to attract the male to mate, after which the male dies. The female moth lays about 500 eggs in one night and then slowly dies.

3. What four stages does a silkworm go through in its life?

The life of a silkworm goes through four stages: egg, larva, pupa and adult.

Silkworm (scientific name: Bombyx mori) is an insect of the order Lepidoptera. It is the main source of silk and plays an important role in human economic life and cultural history. It is native to China and is commonly known as silkworm or nymph in southern China and Taiwan.

The silkworm is called "silkworm" in English because it uses silk to make cocoons. A cocoon is made from a strand of silk that is 300-900 meters long. Today, my country's silk production and exports account for more than 70% of the world's total, and it has become a major silk country that can dominate the world's silk price trend.

Living habits:

Silkworms are metamorphosis insects, the most common of which is the mulberry silkworm, also known as the domestic silkworm, one of the economic insects that feeds on mulberry leaves and spins silk cocoons. The silkworm originated in China, and its development temperature is 7-40℃, and the optimal temperature for breeding is 20-30℃.

Silkworms feed on mulberry leaves. After eating mulberry leaves continuously, their bodies turn white. After a period of time, they begin to shed their skins. They shed their skins for about a day, and do not eat or move, like sleeping. This is called "hibernation". After molting once, they become second-instar larvae. Each time they shed their skin, they grow one year older. The larvae shed their skins four times in total, becoming fifth-instar larvae. After eating mulberry leaves for another eight days, they become mature silkworms and begin to spin silk and make cocoons.

4. What stages does a silkworm go through in its life? What are the characteristics of its development?

The life of a silkworm can be divided into four stages: egg, larva, pupa and adult. There are five instars in the larval stage. There are dormancy periods and differences in mulberry-eating habits between each instar. Therefore, if we break it down, the life of a silkworm can be divided into eight stages.

5. What are the four stages of a silkworm's life? How many days does a silkworm's life cycle last?

After the four stages of egg-larva-pupa-adult, its development is incomplete metamorphosis. How long does it take for silkworms to go through each stage: The growth and development of silkworms are related to temperature, humidity, food, etc., and the accelerator period is generally ten to eleven days. The larval stage is about twenty-five days (specifically, the first instar is four to five days; the second instar is three to four days; the third instar is four days; the fourth instar is six days; the fifth instar is seven to nine days.) The pupal stage is fourteen to eighteen days. The moth stage is three to five days. After the silkworm moth emerges, it no longer eats, and its wings will harden after about an hour. After the wings harden, it will mate. Each female moth will lay about 300 to 400 eggs. The purpose of silkworms emerging into moths is to mate and lay eggs.

6. What are the four stages in the life of a silkworm?

The four changes that a silkworm goes through in its life are: first, egg, second, silkworm, third, pupa, and fourth, butterfly. The four forms are different, which is really amazing! It also gives us a profound revelation: in this world, the same thing will appear in front of us in completely different forms at different times, so when we analyze and solve problems, we must pay close attention to the period and form of things.

7. How many stages are there in the life of a silkworm? What are the characteristics of each stage?

The life of a spring silkworm is divided into four stages: silkworm eggs, silkworms (larvae), silkworm pupae and silkworm moths.

1. Silkworm eggs

The eggs of silkworms that have just been laid are light yellow or yellow, oblate, about 1.2-1.3mm long, about 0.5mm thick, and weigh about 1g. After 1-2 days, the eggs turn into red bean color, and after about 3-4 days, they turn into gray-green or purple. When they are about to hatch, the eggs turn purple-black. After the silkworms hatch, the eggs turn white or light yellow.

2. Silkworm

(1) After hatching, the body of the larva is small (about 2 mm long and 0.5 mm wide) and is brown or black in color.

(2) About 2-3 hours after hatching, the larvae begin to eat mulberry leaves.

(3) After eating mulberry leaves, the silkworm's body grows larger, but the epidermis restricts it, so the silkworm will molt. In the larval stage, the silkworm is divided into 1st instar silkworm, 2nd instar silkworm, 3rd instar silkworm, 4th instar silkworm, and 5th instar silkworm, and molts 4 times in total.

(4) At the end of the fifth instar, the silkworms show signs of maturity and begin to spin silk and make cocoons.

3. Silkworm pupae

(1) About 4 days after the silkworms spin cocoons on the cocoon nest, they transform into pupae.

(2) The appearance of a silkworm pupa is similar to that of a spindle, and it is divided into three body segments: head, thorax, and abdomen. The head is relatively small and has compound eyes and antennae; the thorax has thoracic legs and wings; and the abdomen has 9 body segments.

(3) When the silkworm pupae first emerge, they are light yellow and soft. Later, they gradually turn into yellow, tan or brown, and their bodies gradually become hard.

(4) After dozens of days, the pupa becomes soft again and its color turns into earthy brown, indicating that the silkworm pupa is about to transform into a silk moth.

4. Silkworm moth

(1) The appearance of the silk moth is similar to that of a butterfly, with a small spherical head, bulging compound eyes and antennae, three pairs of thoracic legs and two pairs of wings on the thorax; there are no abdominal legs on the abdomen, and the terminal body segment has evolved into the external genitalia.

(2) The male moth dies after mating, while the female moth begins to lay fertilized eggs 3-4 hours after mating. She can lay about 500 eggs in one night, and then slowly dies.

8. What are the four stages in the life of a silkworm?

The life cycle of a silkworm is from egg to larva, and then from larva to pupa.

, and then from the pupa to the adult, these four stages are metamorphosis insects.

Silkworm eggs: Silkworms reproduce by eggs. Silkworm eggs look like fine sesame seeds, about 1 mm wide and 0.5 mm thick. A female moth can lay 400 to 500 silkworm eggs. 1700 to 2000 silkworm eggs weigh about 1 gram and have a diameter of 0.2 cm. The color of silkworm eggs is light yellow or yellow when they are first laid, and changes to light red bean color or red bean color after 1 to 2 days, and then turns to gray-green or purple after 3 to 4 days. It no longer changes and is called a fixed color.

9. What are the four stages in a silkworm’s life?

The silkworm's life cycle consists of four stages: egg, larva, pupa, and adult. Silkworms eat a lot of mulberry, so they grow very fast and their body color gradually fades.

But its appetite gradually decreases and it even stops eating completely. It spits out a small amount of silk, fixes its abdominal feet on the silkworm seat, raises its head and chest, and stops moving, as if it is asleep. This is called "sleeping".