CATDOLL : CATDOLL: How long is the cicada's growth cycle and its habits?

The life cycle of cicadas is not fixed. Different species of cicadas have different life cycles, some are long and some are short, but the longest will not exceed 17 years. According to biologists, the life cycle of Chinese cicadas is mostly around 3 to 7 years, the life cycle of French cicadas is mostly around 4 years, and the life cycle of North American cicadas is 13 to 17 years, which is the longest known life cycle of cicadas. Cicadas have many habits. Let's talk about the habits of cicadas and their life cycle.

List:

1: Habits of cicadas: A representative species of Cicadidae insects. The male has a sound organ on its abdomen, which can continuously make sharp sounds. The female does not make sounds, but has an auditory organ on its abdomen. The larvae live in the soil, sucking the roots of plants, and the adults eat the juice of plants. Cicadas are incomplete metamorphosis, from eggs and larvae, they molt several times and become adults without going through the pupal period. Tongchan comes from Buddhism. The larvae of cicadas live in the soil and have a pair of relatively strong digging front legs. They use piercing and sucking mouthparts to pierce and suck the juice from the roots of plants, weakening the tree, causing the branches to die, and affecting the growth of trees. Usually they stay in the soil for several years or even more than ten years, such as 3 years, 5 years, and 17 years. These numbers have one thing in common, they are all prime numbers. This is because prime numbers have very few factors, and when they drill out of the soil, they can prevent other cicadas from drilling out together and competing for territory and food.

2: The life cycle of cicadas: There is actually no such thing as a cicada that can only live for seven days. The longest life span of a cicada can reach about 70 days. Moreover, cicadas are considered to be the insects with the longest life span in the world. The life cycle of cicadas in different places is also different. For example, the life cycle of French cicadas is generally four years, while in North America, there are cicadas that live up to 17 years. Generally, the life span of cicadas in China is 3 to 7 years, and about half of them have a life span of 5 years. As for why cicadas can only be seen in summer, it is because before breaking out of the ground and molting into a cicada, they spend most of their life cycle living in the soil.

Cicadas spend most of their lives in the form of larvae living underground, usually staying in the soil for several years or even more than ten years, such as 3 years, 5 years, and 17 years. These numbers have one thing in common: they are all prime numbers. After the larvae emerge from the soil and become adults, their longest lifespan is about 60 to 70 days.

Cicadas usually emerge at dusk or at night. At this time, the larvae crawl out of the ground and climb onto trees, beginning the process of "shedding their skin". After a short while, the cicada's wings harden and it begins to fly.

At the end of June, the larvae begin to emerge as adults. The newly emerged cicadas are green. The males need to use their chirping to attract females to mate. In late July, the female adults begin to lay eggs. The peak egg-laying period is in early and mid-August. The eggs are mostly laid on branches that are 4 to 5 mm thick. The eggs laid by the female cicadas will not hatch into larvae until the second year, when they burrow underground to begin a new life cycle.

Additional information

Summer cicadas chirping

The chirping cicadas are all male cicadas with complete sound organs. Female cicadas do not chirp because their sound organs are not fully developed. The sound organ on the abdomen of male cicadas is very similar to a drum, which will make sounds when vibrated. Its sound muscle can expand and contract about 10,000 times per second. The space between the cover and the eardrum can also play a role of resonance, so the cicada's call is particularly loud.

Female cicadas can roughly understand whether the owner of the voice is healthy and capable of reproduction through their chirping. After some consideration, the female cicadas will fly to the male cicadas they like and complete mating.

Reference source: People's Daily Online - The life span of cicadas is only one month? Wrong! There is a place where cicadas live for 17 years

Reference source: Baidu Encyclopedia - Cicada

How long is the life cycle of a cicada and what are its habits?

life cycle:

Not all cicadas stay underground for 17 years. Most stay in the soil for 2 or 3 years. The 17-year cicada is just one type of cicada. There is a type of cicada in North America that has a very long life cycle of 17 years. Its living habits are very special. In the first 17 years of its life, it is a larva buried underground. When the 17th year is up, it drills out of the soil, emerges as an adult, mates, lays eggs, and then dies.

There is another type of cicada that has the same life cycle, but its life cycle is 13 years. Although there are 13-year and 17-year cicadas in nature, there are no 14-, 15-, or 16-year cicadas. Why do cicadas choose 13 and 17 years as their life cycle, but not 14, 15, or 16 years? The answer is related to "prime numbers" in mathematics.

If the life cycle of the cicada's natural enemies is two years, that is, the natural enemies will appear in large numbers every two years, then the cicadas will inevitably encounter natural enemies when they drill out of the soil in the 14th and 16th years. If the life cycle of the natural enemies is three or five years, the cicadas will encounter natural enemies in the 15th year. In other words, if the cicada will encounter natural enemies, the life cycle is a factor of the cicada's life cycle.

The chances of cicadas being cannibalized will increase significantly. If the 15-year cicadas encounter a large number of predators with a 3-year cycle when they emerge from the soil in large numbers, they will inevitably encounter the same thing the next time they emerge from the soil. What about the 17-year cicadas? If they encounter a natural enemy with a 3-year cycle when they emerge from the soil this year, then the next time they encounter this natural enemy will be 42 years later. There are still two times in between when they can safely emerge from the soil and reproduce the next generation. Therefore, the survival rate of cicadas with prime numbers as their cycle will increase significantly, and they can survive in nature.

Living habits:

1. Cicada larvae live in the soil and have a pair of strong digging forelegs. They use their piercing-sucking mouthparts to suck sap from the roots of plants, weakening the tree, causing branches to die and affecting tree growth.

2. When a black crack appears on the back of the cicada pupa, the molting process begins. The head comes out first, followed by the green body and wrinkled wings. It stays for a moment to allow the wings to harden and darken in color, and then it begins to take off.

3. At the end of June, the larvae begin to emerge into adults. The newly emerged cicadas are green in color and have a maximum lifespan of about 60 to 70 days.

4. They make loud calls on trees and suck sap with their needle-like mouthparts. The larvae live in the soil and suck sap from the roots, which is harmful to the trees.

5. Molting is controlled by a hormone. The front legs of the cicada pupa are hooked, so that when the adult emerges from the empty shell, it can hang firmly on the tree.

6. Whenever the cicada is thirsty or hungry, it will insert its hard mouthparts into the tree trunk and suck juice all day long, absorbing a large amount of nutrients and water into its body to prolong its life.

7. Male cicadas can chirp. Their sound organs are in their abdominal muscles, like a big drum covered with an eardrum. The eardrum vibrates and makes sound. Since the singing muscle can expand and contract about 10,000 times per second, the space between the cover and the eardrum is empty, which can resonate, so their chirping sound is particularly loud.

How long is the growth period of cicadas and their habits

The life cycle of a silkworm goes through four stages: egg → larva → pupa → moth.

The growth and development of silkworms are related to temperature, humidity, food, etc. Generally, the incubation period is 10 to 11 days. The larval stage is about 25 days (specifically, 4 to 5 days for the first instar; 3 to 4 days for the second instar; 4 days for the third instar; 6 days for the fourth instar; and 6 to 8 days for the fifth instar), the pupal stage is 14 to 18 days, and the moth stage is 3 to 5 days.

After the moth emerges from its phoenix, it stops eating and its wings harden about an hour later. After the wings harden, it mates. Each female moth lays about 300 to 500 eggs.

The purpose of silkworms transforming into moths is to mate and lay eggs.

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 produce 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 just laid, and changes to light red bean color or red bean color after 1 to 2 days, and then changes to gray-green or purple after 3 to 4 days. It will no longer change, which is called fixed color. The outer layer of silkworm eggs is a hard eggshell, and the inside is yolk and serosal membrane. The embryo in the fertilized egg continuously absorbs nutrients during the development process and gradually develops into an ant 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.

Ant silkworm: When the silkworm hatches from the egg, its body is brown or black, very small, and has many fine hairs, and looks a bit like an ant, so it is called an 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.

The sleeping nature of silkworms: Silkworms eat a lot of mulberry, so they grow very fast and their body color gradually fades. But their appetite gradually decreases or even completely stops eating. They spit out a small amount of silk, fix their abdomen and feet on the silkworm seat, raise their head and chest, and stop moving, as if they are asleep. This is called "sleeping". The sleeping silkworms may seem motionless on the outside, but they are preparing to shed their skin inside. After shedding the old skin, the silkworms enter a new age. From ant silkworms to spinning silk cocoons, they shed their skin four times in total. Having the sleep nature is one of the growth characteristics of silkworms. Sleep nature is a genetic trait of silkworms and is also affected by the environment. The silkworms currently raised in my country belong to the four-sleeping varieties.

Silkworm age: also known as age period, which indicates the development stage of the silkworm. From the ant silkworm to the first molt is the first age; after waking up from sleep, it enters the second age; after molting again, it enters the third age; after the third molt, it enters the fourth age, and the fourth molt is also called the long sleep. After the long sleep, it enters the fifth age. The fifth-age silkworm grows very fast, with a body length of 6 to 7 cm and a weight of about 10,000 times the weight of the ant silkworm.

Mature silkworms: When silkworms reach the end of the fifth instar, they gradually show the characteristics of maturity: first, the feces they excrete change from hard to soft, and from dark green to leaf green; their appetite decreases, and the amount of food they eat decreases; the front digestive tract is empty, and the chest becomes transparent; then they stop eating completely, their bodies shorten, and their abdomens tend to be transparent; their head and chest are raised, they spit out silk threads from their mouths, and they swing left and right and up and down to find a place to build their cocoons. Such silkworms are called mature silkworms.

silkworm

Cocooning during the adult stage: People put mature silkworms in special containers or on cocoons, and the silkworms will spin silk and make cocoons.

Cocooning can be divided into four processes: 1. The mature silkworms first spit out silk, which is bonded to the cocooning device, and then spit out silk to connect the surrounding cocoon branches to form a cocoon support, that is, a cocoon net. The cocoon net does not have a cocoon shape, but is just some soft and messy cocoon silk layers to serve as a cocoon support. 2. After the silkworms make a cocoon net, they continue to spit out messy silk circles to thicken the inner layer of the cocoon net, and then spit out silk in an S-shaped manner, and the outline of the cocoon begins to appear, which is called a cocoon coat. The silk fibers of the cocoon coat are fine and brittle, arranged very irregularly, and have a high content of sericin. 3. After the cocoon coat is formed, the cocoon cavity gradually becomes smaller, and the front and rear ends of the silkworm body bend back to form a "C" shape. The silkworm continues to spit out cocoon silk, and the spinning method changes from S shape to ∞ shape, which begins the process of forming a cocoon layer. 4. When the silkworm's body is greatly reduced due to a large amount of silk, the swing speed of the head and thorax slows down, and there is no certain rhythm. The spinning begins to appear messy, forming a loose and soft cocoon silk layer, called a pupa lining.

Silkworm pupa: After the silkworms make 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 silkworm pupa from the lines and brown dots on the abdomen. When the silkworm just turns into a pupae, its 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.

Silkworm pupa

Silkworm moth (adult): Silkworm moths are shaped like butterflies, with white scales all over their bodies, but because their two pairs of wings are small, they have lost the ability to fly. The head of the silkworm moth is spherical, with bulging compound eyes and antennae; the thorax has three pairs of thoracic legs and two pairs of wings; the abdomen has no ventral legs, and the terminal body segment has evolved into external genitalia. The female moth is large and crawls slowly; the male moth is small and crawls faster, with its wings vibrating rapidly, looking for a mate. Generally, the female moth can lay fertilized eggs 3 to 4 hours after mating. The male dies after mating, and the female moth can lay about 500 eggs in about one night, and then slowly dies.

The silkworm lays eggs, hatches into silkworms, turns into pupae, and then turns into moths, completing the cycle of a new generation. This is the life history of the silkworm.

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 and makes cocoons. The mulberry 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, and their bodies turn white after eating mulberry leaves continuously. After a period of time, they begin to shed their skins. The molting lasts for about a day, and they do not eat or move like sleeping. This is called "hibernation". After molting once, it is a second-instar larva. It grows one year older each time it molts. The larvae molt four times in total, becoming fifth-instar larvae, and then eat mulberry leaves for 8 days to become mature silkworms, and begin to spin silk and make cocoons.

Not all cicadas stay underground for 17 years. Most stay in the soil for 2 or 3 years. The 17-year cicada you mentioned is just one type of cicada. There is a type of cicada in North America that has a very long life cycle of 17 years. Its life habits are very special. In the first 17 years of its life, it is in the form of a larva buried underground. When the 17th year comes, it drills out of the soil, emerges as an adult, mates, lays eggs, and then dies. There is another type of cicada with the same life cycle, but the cycle is 13 years. Although there are 13-year and 17-year cicadas in nature, there are no 14-, 15-, or 16-year cicadas. Why do cicadas choose 13 and 17 years as their life cycle, but not 14, 15, or 16 years? The answer is related to "prime numbers" in mathematics. If the life cycle of the cicada's natural enemies is two years, that is, the natural enemies will appear in large numbers every two years, then the 14- and 16-year cicadas will inevitably encounter natural enemies when they drill out of the soil. If the life cycle of the natural enemies is three or five years, the 15-year cicada will encounter natural enemies. That is to say, if the cicada encounters a natural enemy whose life cycle is a factor of the cicada's life cycle, then the chance of the cicada being cannibalized will increase significantly. If the 15-year cicadas encounter a large number of natural enemies with a cycle of 3 years when they drill out of the soil in large numbers, then the next time the 15-year cicadas drill out of the soil, they will inevitably encounter the same thing. What if it is a 17-year cicada? If they encounter a natural enemy with a cycle of 3 years when they drill out of the soil this year, then the next time they encounter this natural enemy will be 42 years later. There are still two times in between to drill out of the soil safely and reproduce the next generation. Therefore, the survival rate of cicadas with prime numbers as their cycle will increase significantly, and they can survive in nature.