Why do silkworms have two heads?Why does the silkworm keep holding its head up

Hello, the silkworm is common in daily life, and its larval stage is long cylindrical, consisting of three parts: head, thorax and abdomen. The head is covered with a grayish-brown bony skull, and each of the three parts of the thorax has 1 pair of thoracic feetThere are 4 pairs of gastropods and 1 pair of caudal feet in the 10 links of the abdomen, and there is 1 caudal horn on the dorsal surface of the 8th abdominal segment**;There is one pair of valves on each side of the body of the 1st thoracic segment and 1st to 8th abdominal segments. The newly hatched larvae are covered with black and brown bristles, and their bodies are small like ants, and they are called ant silkworms.

Ants and silkworms grow rapidly by feeding on mulberry leaves, and their body color gradually turns blue and white.

Because there are two rows of corresponding black pores on both sides of the silkworm's body, which are brought to the tail of the silkworm, the silkworm sometimes looks like it has two heads. The head of the first-in-star silkworm is brown in color, the body is very small, the body surface has fine hairs, and the head is reddish-black. The head of the second-instar silkworm is still reddish-black, the color of the dorsal thorax is white, and the color of the dorsal abdomen is gray.

The head of the third-instar silkworm is no longer black, but gray. Starting from the fourth instar silkworm, the head mainly begins to be grayish-white.

If you use a magnifying glass to magnify the head of the silkworm**, you will find the difference between the head and tail of the silkworm, and the silkworm is not two heads. The head has two black pores that appear to be eyes, but in fact, the eyes of the silkworm grow on the head, very close to its mouth, and there are six single eyes on the left and right sides. You actually distinguish the head and tail according to the black stomata of the silkworm, and you don't find out where the eyes of the head of the silkworm are, so that you mistakenly think that the silkworm has two heads, but the silkworm has only one head.

The silkworm has only one head, not two heads, and the body structure of the silkworm is divided into three parts: head, thorax and abdomen, with a total of thirteen sections.

The silkworm keeps its head up, indicating that it is molting or preparing to form a cocoon, which is a normal condition for the physiological development of the silkworm. Silkworms have four stages, which are egg, larva, pupa and adult. Among them, the larvae have several molts in the process of growth, and will eat mulberry leaves before molting, and then will enter the dormant period, at this time they will remain motionless, and will come out of the old skin after the dormant period.

When the silkworm is about to molt, the body will become a little transparent, and the color of the body will gradually fade.

Tips: 1. The temperature of silkworm raising in summer and autumn is high, so it is necessary to open doors and windows and strengthen indoor ventilation. Mulberry leaves are sprayed with water, and the indoor electric fan blows a breeze, which is conducive to indoor cooling.

2. If the diseased silkworms are found, they should be cleaned up in time, put them into a disinfection basin containing bleaching powder solution or lime slurry, and prohibit the diseased silkworms from feeding livestock and poultry to prevent the spread of pathogens and pollute the environment.

3. High temperature in summer and autumn, rapid reproduction of pathogens, pay attention to on-demand leaf picking, timely leaf transportation, and reasonable leaf storage. The mulberry storage pond should be disinfected once at each age, and mulberry leaves should not be fed overnight.

Summary. The head becomes larger and greener, the body is stiff, and then swallows green water and dies, a silkworm disease caused by bacteria. The main ones are:

Cataplexy. i.e., bacterial poisoning disease. The pathogen is Bacillus thuringiensis cataplexy variety, referred to as cataplexy, Eubacteria, Bacillus spp.

In the summer and autumn silkworm period, there are more diseases, and the pathogen is transmitted orally. The disease suddenly stopped, there was spasmodic tremor, the body was paralyzed, and he died on his side, and the corpse quickly decomposed and discolored, and a black-brown foul smelled filth. The time from infection to death usually takes minutes to hours.

Hello, I am inquiring for you, please wait a while, I will reply to you immediately Whether it is a larva or an adult.

If you are an adult, you are going to pupate.

The larvae are caused by disease.

The head becomes larger and greener, the body is stiff, and then swallows green water and dies, a silkworm disease caused by bacteria. The main ones are: cataplexy.

i.e., bacterial poisoning disease. The pathogen is Bacillus thuringiensis cataplexy variety, referred to as cataplexy, Eubacteria, Bacillus spp. In the summer and autumn silkworm stage, the incidence is more common than that of cherry fingers, and the pathogen is transmitted orally.

The disease suddenly stopped eating mulberry, there was spasmodic tremor, the body was paralyzed, and he fell on his side and died, and the corpse soon decomposed and discolored, and exuded black-brown foul-smelling filth. The time from infection to death is usually a few minutes to several hours.

There are several scenarios.

First, the silkworm is already hungry, and there are no mulberry leaves to eat on the silkworm seat, so it raises its head and swings back and forth, which is a signal to seek food, and the mulberry leaves should be fed as soon as possible.

The second is silkworm poisoning. This situation is divided into several types, such as: 1. Silkworms eat mulberry leaves contaminated with pesticides; 2. Eating mulberry leaves that have been contaminated with the urine of insects in the wild (generally in individual cases, not in large quantities); 3. There is a factory next to the silkworm house, which discharges harmful gases and is smelled by silkworms; 4. Mosquito coils lit at home and smelled by silkworms; 5. Hail lead rotten silkworms come into contact with other peculiar smells, such as spraying perfume or toilet water after applying nail polish and entering the silkworm room.

In the second case, silkworms not only bobb their heads back and forth, but also tend to spit out yellow intestinal fluid. After a few meals, silkworms can be slowly relieved and adjusted to a normal situation, and at worst, they will no longer eat and die slowly.

The third kind, after the silkworm matures, it looks back and forth to find a place to spin silk and form a cocoon, generally after the 6th day of the fifth instar, the silkworm exhausts the metabolites in the body, and becomes shiny, which means that the silkworm is mature. At this time, the source of the ripe silkworm will look up and swing back and forth to find a place to fix the silk, and the tufts should be put on the silkworm seat in time to spin the silk camp cocoon.

Is it "eyes" and "mouthparts"?

The larva of the silkworm is a meat worm, commonly known as the "silkworm baby".

The eyes of the baby silkworm grow on the head, which is relatively close to the mouth of the silkworm, and there are six single eyes on the left and right sides. However, the eyesight of silkworm babies is not very good, and there are only some photoreceptor cells, so they can only feel the intensity of light, and cannot see the surrounding things clearly.

The mouthparts of the silkworm baby (that is, the mouth it uses to eat mulberry leaves) are chewing mouthparts. Chewing mouthparts are typical of insects, and other types have evolved from this type. Chewing mouthparts are used to eat solid food.

Like a human mouth, it has an upper lip, a lower lip, an upper jaw (teeth), and a tongue, but at the same time it also has lower lip whiskers, a lower jaw, and lower jaw whiskers. The front end of the palate has sharp teeth called incisions, which are used to cut food; It has a rough surface at the back called the grinding zone, which is used to grind food.

The silkworm will rise from both ends, indicating that it is very healthy.

Silkworm in the larval stage to shed four times, after molting will begin to eat mulberry leaves, when its body is yellow and transparent, and begin to look up, indicating that it is going to enter the sleep period, after a period of time will begin to molt. If it continues to raise its head after four molts, it is about to start spinning, and it needs to be moved to the cocoon rack so that it can form a cocoon.

Silkworms are lepidopteran insects, the main raw material of silk, and occupy an important position in human economic life and cultural history. Native to China, South China and Taiwan, commonly known as silkworm babies or mothers. The silkworm is named in English because it rolls violently with silk cocoons.

The cocoon is made of a single branch of silk that is 300-900 meters long. Nowadays, the production and export volume of cocoon silk in our surplus country account for more than 70% of the world's total, and it has become a major cocoon silk country that can dominate the world's cocoon silk trend.

The elevation of the silkworm head indicates that the silkworm has begun to molt, and the outer skin of the silkworm is about to begin to molt;

Before the cocoon, the feces pulled by the silkworm baby will be abnormally large (each time the skin feces is taken off, it will be larger, but this time it is not peeled), and the leaf particles in the feces can be seen, the leaves are almost not digested, and the body is transparent, which are the characteristics of cocooning.

Before the cocoon is about to begin, there is another procedure - drainage, the silkworm only poops, and this time it is urine, but sometimes the urine and the stool will come out together, the stool is yellowish-white, and the cocoon should be placed in a place with an angle, not in a flat place.