CATDOLL : CATDOLL: What are earthworms? Where do they come from?

Chinese name: Pheretima

Latin name: Pheretima

English nameEarthworm

Commonly known as earth dragon, earthworm

Chinese medicine name Earth Dragon [Edit this paragraph] Introduction The body is about 100mm long and weighs about 0.5 grams. It lives in moist, loose and fertile soil. The body is cylindrical and consists of more than 100 body segments. The front segment is slightly pointed, the back end is slightly rounded, and there is an indistinct ring at the front end. The ventral surface is lighter in color. Most of the body segments have bristles in the middle, which play a role in fixing and supporting the earthworm when crawling. After the 11th body segment, there is a dorsal hole on the back line of each segment, which is conducive to breathing and keeping the body moist.

Earthworms move forward through muscle contraction and avoid strong light and move towards weak light.

Also known as angleworm. Lumbricus terrestris John Markham is an invertebrate

Any of more than 1,800 species of terrestrial animals of the class Oligochaeta, phylum Annelida, especially those of the genus Lumbricus. There are 17 native species in the United States and 13 introduced from Europe, of which the terrestris is the most common. Earthworms are found in almost all soils of the world that have the right moisture content and contain sufficient organic matter. One species of Australian earthworm can be up to 3.3 metres (11 m) long. The terrestris is about 25 centimetres (10 cm) long and is light reddish brown, the reddish colour being due to the presence of hemoglobin in its blood. Some earthworms (such as the British Allolobophora chlorotica) are green.

The body of an earthworm is divided into many segments (up to 150 in the case of the terrestrial earthworm). Certain internal organs (such as excretory organs) are found in each segment. Segments 32, 6, 5, and 37 are slightly thicker, have no intersegmental grooves, are slightly lighter in color, and secrete a sticky substance during the reproductive season to form a cocoon to encase the eggs. The body of an earthworm tapers at both ends, with a slightly blunt tail. Earthworms have no visual or auditory organs, but can sense light and vibrations. They feed on decaying organisms in the soil, swallowing large amounts of soil, sand, and tiny stone fragments while eating. It is estimated that earthworms eat and excrete an amount of waste equal to their body weight each day.

Earthworms are hermaphrodites, but they need to undergo cross-fertilization. During mating, the two earthworms embrace each other and secrete mucus to stick their ventral surfaces together. Each of them discharges sperm into the other's spermatophore. After mating, the two individuals separate and form a cocoon. The earthworms retreat backwards from the cocoon. When the cocoon moves forward to the 14th body segment, the mature eggs fall into it. When it passes the 9th to 10th body segment, the sperm from the other party in the spermatophore escapes and fertilizes the eggs in the cocoon. 24 hours after mating, the cocoon comes out from the head end of the earthworm and remains in the soil. Usually after 2 to 4 weeks, the tiny larvae emerge from the cocoon after resembling adults. Sexual maturity is achieved after 60 to 90 days, and development is complete after about a year.

Earthworms usually stay on the surface of the soil, but can burrow down to a depth of 2 meters (7) during droughts or in winter. One Asian species climbs trees to avoid drowning after a heavy rain. Earthworms are food for many birds and animals, and indirectly for humans. They loosen the soil to facilitate aeration and drainage, and drag organic matter into the burrows to accelerate decomposition, thereby increasing the nutrients needed for plant growth. Earthworms can also be used as fish bait, so they are commonly known as fishing worms.

Earthworms are a common terrestrial annelid that lives in the soil. They hide during the day and come out at night. They feed on decaying organic matter and swallow it together with the soil. They also eat plant stems and leaves and other debris. Earthworms can loosen the soil, improve the soil, increase fertility, and promote agricultural production. There are about 2,500 species of earthworms in the world, and 229 species have been recorded in my country. The genus Pheretima has many species, and there are more than 2,000 species in my country. [Edit this paragraph] Relationship with humans Earthworms feed on animal and plant debris in the soil. They often drill holes underground to loosen the soil, making it easier for water and fertilizer to enter and improve soil fertility, which is beneficial to plant growth. Earthworms can be used as poultry feed and are the "meat" food that chickens and ducks like. Earthworms are also widely adaptable in freshwater fishing and are suitable bait for various waters, fish, and climates. But earthworms also have a harmful side. There is a parasite that lives in pigs - the larvae of the pig lungworm live in earthworms for a period of time during their growth and development. Therefore, in areas where the pig lungworm is prevalent, earthworms provide convenient conditions for the reproduction of this parasite. Live earthworms can easily spread diseases, such as tapeworm disease and asthma in pigs. They can spread tracheosyngamy, ringworm disease, heterotrichomoniasis and wedge-shaped tapeworm disease to poultry.

Earthworms are decomposers. For humans, they can decompose organic waste produced by humans and turn it into inorganic matter for plants to use. So if there are earthworms in the yard, vegetables or flowers will grow better... At the same time, human activities will provide earthworms with a certain source of energy, such as food. However, human pollution of soil and water will cause great harm to the living environment of earthworms and threaten their lives.

Earthworms can also be used as feed, food and medicine, and are of great benefit to humans.

At present, people are increasingly aware of the importance of earthworms in agricultural, forestry and animal husbandry production and their special role in environmental protection. According to a survey, there are about 150,000 to 1.8 million earthworms per hectare of land in my country. Due to the digging and omnivorous nature of earthworms, the earthworm manure discharged by earthworms per hectare of land can reach tens to hundreds of tons each year. The earthworm manure rich in humus is an excellent fertilizer for plant growth. The activities of earthworms can also improve the soil, accelerate the decomposition of organic matter in the soil, and restore and maintain the ecological balance of the soil. In addition, earthworms are increasingly valued in terms of processing organic waste in garbage, degrading pollutants in the environment, and providing new sources of protein for humans.

Earthworms are very beneficial to human beings. First, earthworms move in the soil, making the soil loose, allowing air and water to penetrate deeper into the soil, which is beneficial to plant growth and can improve the soil. Second, earthworms can improve soil fertility. The decayed organic matter and a large amount of soil particles eaten by earthworms are digested and excreted into feces, which are rich in nitrogen, phosphorus, potassium and other nutrients. Third, the body of earthworms contains a large amount of protein and fat, which has high nutritional value and is an excellent protein feed and food. Fourth, the efficiency of using earthworms to process organic waste is very high. For example, 100 million earthworms can eat 40 tons of organic waste a day. Therefore, earthworms are very beneficial to human beings. Therefore, my country and many countries in the world are vigorously developing the use and breeding of earthworms. [Edit this paragraph] External morphology The body of the earthworm is cylindrical and slender, with similar segments, and intersegmental furrows between segments.

The head is not obvious, and is composed of the peristomium and the prostomium in front of it. When the prostomium expands, it can stretch and move, and has the functions of digging, picking up food, and feeling touch.

The perioral segment is the first body segment, and the mouth is located on the ventral side, below the preoral lobe. The anus is endless and appears as a straight slit. Setae begin to be present from the second body segment, and are arranged around the body segment, called perichaetine.

The setae are simple, slightly S-shaped, and most are located in setae follicles within the body wall.

In sexually mature individuals, the 14th to 16th segments are dark and swollen, without intersegmental grooves or bristles (Pheretima hupeiensis has bristles on the ventral surface), and are shaped like a ring, called the genital belt or annulus (clitellum). The shape and position of the genital belt vary according to the genus. The epithelium of the genital belt is glandular epithelium, and its secretions can form egg cocoons (cocoons) during the reproductive period. There is a female genital opening in the first segment of the genital belt, which is the 14th segment, in the center of the ventral surface; there is a pair of male genital openings on both sides of the ventral side of the 18th segment. There are 2 to 4 pairs of seminal receptacle openings, which vary according to the species.

Starting from the 11-12 intersegmental groove, there is a dorsal pore at the dorsal line, which can discharge coelomic fluid and moisten the body surface, which is conducive to the earthworm's respiration and movement in the soil. [Edit this section] Body wall and secondary coelom The body wall of the earthworm is composed of cuticle, epithelium, circular muscle layer, longitudinal muscle layer and coelomic epithelium. The outermost layer is a single layer of columnar epithelial cells, and the secretions of these cells form a cuticle. This membrane is extremely thin, composed of collagen fibers and non-fibrous layers, with small holes on it. Columnar epithelial cells are interspersed with glandular cells, which are divided into mucus cells and protein cells, and can secrete mucus to moisten the body surface. When earthworms encounter severe stimulation, mucus cells secrete a large amount of mucus cells to wrap the body into a mucus membrane, which has a protective effect. There are short basal cells at the base of the epithelial cells, and some people believe that they can develop into columnar epithelial cells. Sensory cells gather to form sensory organs, which are scattered between epithelial cells, and the base is connected to the nerve fibers of a thin layer of nerve tissue under the epithelium. In addition, there are photoreceptor cells, which are located at the base of the epithelium and are also connected to the nerve fibers underneath.

The inner side of the nerve tissue below the epithelium is a narrow circular muscle layer and a developed longitudinal muscle layer. The circular muscle layer is composed of muscle cells arranged around the body. The muscle cells are buried in the connective tissue and arranged irregularly. The longitudinal muscle layer is thick and arranged in bundles. Each bundle is separated by a connective tissue membrane containing microvessels. One end of the muscle cell is attached to the connective tissue membrane between the muscle bundles, and the other end is free. The longitudinal muscle layer is a body cavity epithelium composed of a single layer of flat cells.

The muscles of earthworms are oblique muscles, which generally account for about 40% of the body volume. They are well-developed and flexible. When the longitudinal muscle layer of some segments of earthworms contracts and the circular muscle layer relaxes, this segment becomes thicker and shorter, and the setae that are attached to the body wall and extend obliquely and backwards extend and insert into the surrounding soil; at this time, the circular muscle layer of the previous segment contracts and the longitudinal muscle layer relaxes, and this segment becomes thinner and longer, and the setae retract, breaking away from the surrounding soil. In this way, the setae of the next segment support and push the body forward. In this way, the contraction wave of the muscles is gradually transmitted from front to back along the longitudinal axis of the body, causing the earthworm to move.

The earthworm has a secondary body cavity, which is very wide and contains internal organs. The body cavity is filled with coelomic fluid, which contains coelomic cells such as lymphocytes, amebocytes, and mucus cells. When the muscles contract, the coelomic fluid is under pressure, which increases the pressure on the earthworm's body surface, making the body fuller, with sufficient hardness and pressure resistance. The body surface is rich in mucus, moist and smooth, so it can move smoothly through the soil.

The body cavity is divided into multiple coelomic compartments by diaphragms according to body segments, and each compartment is connected by a small hole. Each coelomic compartment is formed by the development of two coelomic sacs on the left and right. The outer side of the coelomic sac forms the parietal coelomic membrane, and the inner side forms the dorsal mesentery and ventral mesentery except for the middle part forming the visceral coelomic membrane. The ventral mesentery of earthworms has degenerated, and only the part between the intestine and the ventral blood vessels exists; the dorsal mesentery has disappeared. The part between the front and rear coelomic sacs is tightly attached together, forming a septum. Some species do not have a septum in the esophagus area.

The parirtal peritoneum is obvious in the body wall. The visceral peritoneum of the intestinal wall is degenerate. The visceral peritoneum of the midgut is specialized into yellow cells (chloragogan cells). It may have an excretory function. [Edit this section] Digestive system The digestive tract runs longitudinally in the center of the body cavity, passing through the diaphragm. The muscle layer of the tube wall is well developed, which can enhance peristalsis and digestion. The digestive tract is differentiated into the mouth, oral cavity, pharynx, esophagus, gizzard, stomach, intestine, anus and other parts. The oral cavity can be turned out from the mouth to ingest food. The muscles of the pharynx are well developed, and the muscle contraction and expansion of the pharyngeal cavity can assist in food ingestion. There are single-cell pharyngeal glands outside the pharynx, which can secrete mucus and protease, and have the function of moistening food and preliminary digestion. Behind the pharynx is a short and thin esophagus, whose wall has esophageal glands that can secrete calcium to neutralize acidic substances. Behind the esophagus is a well-developed muscular gizzard, lined with a thick layer of cuticle, which can grind food. From the mouth to the gizzard, the ectoderm is formed and belongs to the foregut. The digestive tract behind the gizzard is rich in microvessels and glands, called the stomach. There is a circle of gastric glands in front of the stomach, which function like pharyngeal glands. After the stomach, starting from about the 15th body segment, the digestive tract expands to form the intestine, and its dorsal center is concave to form a blind passage (typhlosole), which increases the digestion and absorption area. Digestion and absorption functions are mainly carried out in the intestine. The visceral cavity membrane of the outermost layer of the intestinal wall is specialized into yellow cells. Starting from the 26th body segment, a pair of cone-shaped caeca (caeca) extend forward on both sides of the intestine, which can secrete a variety of enzymes and are important digestive glands. The stomach and intestine are derived from the endoderm and belong to the midgut. The hindgut is shorter, occupying about 20 body segments at the rear end of the digestive tract, without a blind passage and no digestive function. It opens to the outside of the body through the anus. [Edit this section] The circulatory system is composed of longitudinal blood vessels, circular blood vessels and microvessels, and is a closed-tube circulation. The lumen of the blood vessels is formed by the residual gap formed by the continuous expansion and displacement of the primary body cavity by the secondary body cavity.

The longitudinal blood vessels include the dorsal vessel located in the center of the back of the digestive tract and the ventral vessel located in the center of the ventral side. The dorsal vessel is thicker and can pulsate, with blood flowing from back to front; the ventral vessel is thinner, with blood flowing from front to back. Just below the ventral nerve cord is an even thinner subneural vessel. There is a shorter lateral oesophageal vessel on each side of the esophagus. The main circumferential blood vessels are the heart, which has 4 to 5 pairs (P. hupeiensis has 4 pairs, P. aspergrillum has 5 pairs), located in the front of the body, and the position varies depending on the species. The heart connects the dorsal and ventral vessels. It can pulsate, has valves inside, and blood flows from the dorsal side to the ventral side. The parietal vessels are connected to the dorsal and subneural vessels, and there is generally one pair per body segment except for the front part of the body. The blood on the body wall is collected into the dorsal vessel

The blood vessels of earthworms have not differentiated into arteries and veins. The blood contains blood cells and the plasma contains hemoglobin, so it appears red.

The main blood circulation route is that the dorsal blood vessels collect nutrient-containing blood from a pair of dorsal intestinal blood vessels and oxygen-containing blood from a pair of wall blood vessels in each body segment after the 14th body segment, and flow from back to front. Most of the blood enters the abdominal blood vessels through the heart, and a part of it enters the pharynx at the front end of the body through the dorsal blood vessels. The branches in the esophagus and other places enter the esophageal lateral blood vessels. The blood in the abdominal blood vessels flows from front to back, and each body segment has branches to the body wall, intestines, kidney tubes, etc., and gas exchange is carried out in the body wall. The oxygen-rich blood returns to the esophageal lateral blood vessels at the front end of the body (before the 14th body segment), while most of the blood (after the 14th body segment) returns to the subneural blood vessels, and then enters the dorsal blood vessels through the wall blood vessels of each body segment. After the 14th body segment, the abdominal blood vessels branch into abdominal intestinal blood vessels under the intestine of each body segment and enter the intestine, and then enter the dorsal blood vessels through the dorsal intestinal blood vessels above the intestine. [Edit this section] Respiration and excretion Earthworms exchange gases on their body surface. Oxygen dissolves in the moist film on the body surface, then penetrates the cuticle and epithelium, reaches the microvascular plexus, and is combined with oxygen by hemoglobin in the plasma and transported to various parts of the body. The epithelium of earthworms secretes mucus, and the dorsal pores discharge body cavity fluid, which often keeps the body surface moist and is conducive to respiration. Some people believe that earthworms can also breathe in water or perform panoxygenation.

The excretory organ of earthworms is the metanephric duct. In general, each body segment of the species has a pair of typical metanephric ducts, which are called macronephric ducts. The genus Anclidae does not have macronephric ducts, but has three types of micronephric ducts: parietal micronephridium is located on the inner surface of the body wall, is very small, and has 200 to 250 per body segment, has no renal opening at the inner end, and the renal pore opens on the body surface. Septal micronephridium is located on the front and back sides of each diaphragm after the 14th body segment, generally has 40 to 50 per side, has a renal opening in the shape of a funnel, has cilia, and is connected to the ciliated micronephric duct of the internal organs below, through the non-ciliated excretory duct in the lumen, and opens in the intestine. Pharyngeal micronephridium is located on both sides of the pharynx and esophagus, has no renal opening, and opens in the pharynx. The latter two types of micronephridium are also called digestive micronephric ducts. Various small renal tubules are rich in microvessels, and some renal openings open into the body cavity, so they can eliminate metabolic products in the blood and body cavity. Yellow cells outside the intestine can absorb metabolic products, then fall off into the body cavity fluid, then enter the renal opening and are discharged from the renal tubules. [Edit this section] Nervous system Earthworms are typical cord-type nerves. The central nervous system has a pair of suprapharyngeal nerve books (brain) located on the dorsal side of the third body segment and the subpharyngeal ganglion located on the ventral side between the third and fourth body segments, and the two are connected by the peripharyngeal nerve. A ventral nerve cord extends from the subpharyngeal ganglion to the back of the body, with a ganglion in each segment). The peripheral nervous system has 8 to 10 pairs of nerves emitted from the front side of the suprapharyngeal ganglion, distributed to the preoral lobe, oral cavity, etc.; the subpharyngeal ganglion branches out nerves to the body wall of several body segments at the front of the body. Each ganglion of the ventral nerve cord emits 3 pairs of nerves distributed in the body wall and various organs, and the nerves extending from the suprapharyngeal ganglion to the digestive tract are called the sympathetic nerve system.

Each nerve in the peripheral nervous system contains sensory fibers and motor fibers, and has conduction and reaction functions. Sensory nerve cells can transmit the stimulation received by the epithelium to the adjustor neuron of the ventral nerve, and then transmit the impulse to the motor nerve cells, which are connected to the muscle and other reactors through nerve fibers to cause a reaction. This is a simple reflex arc. The three giant fibers in the ventral nerve cord run through the entire cord and transmit impulses very quickly, so earthworms react quickly when stimulated.

The sensory organs are not well developed, and the small protrusions on the wall are the surface sensory papillae, which have the function of touch; the oral sensory organs are distributed in the mouth, which have the function of taste and smell; the photoreceptors are widely distributed on the body surface, with more in the preoral lobe and the front few segments of the body, and none on the ventral side, which can distinguish the intensity of light and have the reaction of avoiding strong light and tending to weak light. [Edit this paragraph] The reproductive system is hermaphroditic, and the reproductive organs are limited to a few segments in the front part of the body, with a complex structure.

Female reproductive organs: There is a pair of ovaries, which are very small and consist of many very thin ovarian tubes, located behind the anterior diaphragm of the 13th body segment. There is a pair of oviduct funnels, located in front of the posterior diaphragm of the 13th body segment, and connected to a short oviduct. The two oviducts meet under the ventral nerve cord on the ventral side of the 14th body segment and open at the midline of the abdomen, which is called the female genital pore. There are also three pairs of seminal receptacles (4 pairs in P. differingens, 2 pairs in P. aspergillum and P. californica), located in the 7th, 8th and 9th body segments. The seminal receptacle consists of the ampullaa, the ampulla tube and a blind tube (diverticulum). It is the place where sperm is stored. The seminal receptacle openings are on both sides of the ventral surface between the 6th/7th, 7th/8th and 8th/9th body segments.

Male reproductive organs: There are two pairs of testes, which are very small and located in the seminal sac in the 10th and 11th body segments. There are two pairs of sperm funnels, which are located close to the bottom of the testes, with a bulging front end and a cilia at the mouth, and are connected to the thin vas deferens at the back. The two tubes merge into one in the 13th body segment, extending backwards and opening on both sides of the 18th body segment, which is the male genital opening. There is a pair of prostate glands, located on one side of the male genital opening. The prostate duct opens at the end of the vas deferens and secretes mucus related to the activity and nutrition of sperm. The testicular sac is connected to the seminal vesicle in the 11th and 12th body segments, and the seminal vesicle is filled with nutrient solution. After the testes produce sperm cells, they first enter the seminal vesicle for development, and when sperm are formed, they return to the testicular sac and are discharged from the vas deferens through the sperm funnel.

The sperm and eggs of earthworms do not mature at the same time, so they reproduce with cross-fertilization and mating. During mating, the front ventral surfaces of the two individuals face each other, with their heads facing in opposite directions, and they are tightly attached to each other by the mucus secreted by the reproductive belt. The male genital pores of each are close to the spermatocyst pores of the other, and the sperm is sent into the spermatocyst of the other through the protrusions of the reproductive pores. After exchanging sperm, the two earthworms separate. When the eggs mature, the reproductive belt secretes a sticky substance, forming a mucus tube outside the reproductive belt, and the eggs are discharged into it. When the earthworm moves backward, the spermatocyst pore moves to the mucus tube, and the sperm is discharged into the tube. The sperm and eggs are fertilized in the mucus tube, and finally the earthworm exits the mucus tube, and the tube remains in the soil, with both ends closed, forming an egg cocoon, and the eggs develop in the egg cocoon. The egg cocoon is small, about the size of a mung bean, light brown in color, and contains 1 to 3 fertilized eggs.

Earthworms develop directly without a larval stage. The fertilized egg undergoes completely unequal cleavage and develops into a coelomic blastocyst, which forms a gastrula by invagination. After 2 to 3 weeks, the small earthworms hatch and break out of the cocoon.

Some people have reported that Pheretima circumflexus has parthenogenesis. [Edit this paragraph] The impact of temperature on its life activities Earthworms are cold-blooded animals, and their body temperature changes with the changes in the external environment temperature. Therefore, earthworms are generally more dependent on the environment than warm-blooded animals. The environmental temperature not only affects the body temperature and activities of earthworms, but also affects the metabolism, growth and development, and reproduction of earthworms. In addition, temperature also has a greater impact on other living conditions, thereby indirectly affecting earthworms. Therefore, temperature is one of the most important living conditions for earthworms.

Generally speaking, the activity temperature of earthworms is within the range of 5-30℃, they enter a dormant state at 0-5℃, and die below 0℃. The most suitable temperature is about 20-27℃, at which they can grow, develop and reproduce well. At 28-30℃, they can maintain a certain growth; above 32℃, growth stops; below 10℃, the activity is sluggish; above 40℃, they die, and the optimum temperature for earthworm cocoon hatching is 18-27℃. It can be seen that the highest lethal temperature of earthworms is lower than that of other invertebrates. It is best to have a breeding farm indoors in the southern region. In summer, ventilation and moisture retention are provided, and in winter, just closing windows to keep warm can produce normally throughout the year (the temperature here refers to the temperature of the base material, because the temperature of the air is different from the temperature of the base material, for example: when the air temperature is 0℃, the base material temperature is about 12℃; when the air temperature is 38℃, the base material temperature is only about 28℃, because the manure contains extremely high moisture). [Edit this section] How to reproduce offspring Earthworms are hermaphrodites. The male reproductive organs are located at the back of the 10th and 11th segments. There are two pairs of testicular sacs, each of which contains a testis and a sperm infundibulum, which are connected to the latter pair of spermatic vesicles through small holes on the diaphragm. The two pairs of spermatic vesicles are located in the 11th and 12th segments. After the sperm cells are produced in the testis, they first enter the spermatic vesicles for development, and then return to the testicular sacs after maturity, and are discharged from the spermatic funnel through the vas deferens. The two vas deferens are parallel to each other after the 13th segment. When they reach the 18th segment, they meet with the branch and main tubes of the prostate and are discharged from the male genital pore, which is on both sides of the ventral surface of the 18th segment. The female reproductive organs have a pair of grape-shaped ovaries, which are attached to the back of the diaphragm of the 12th and 13th segments. The mature eggs fall into the body cavity, pass through a pair of egg infundibulums in the 13th segment, pass through the shorter oviduct, meet at the 14th segment, and are discharged from the female genital pore, which has only one female genital pore. In addition, there are 2 or 3 pairs of spermatheca in the 6th to 9th segments, which are places for receiving and storing foreign sperm. They open on both sides of the abdominal intersegmental groove between the 6th and 9th segments.

Although earthworms are hermaphrodites, they still need cross-fertilization because their sex cells mature at different times. The male reproductive cells of earthworms mature first. After mating, the two earthworms will mate. During mating, the accessory glands secrete mucus, which makes the ventral surfaces of both sides stick to each other, and the head ends are separated. The male genital pore is opposite to the spermatheca pore of the opposite sex. The semen is discharged from each male genital pore and enters the spermatheca through the spermatheca pore of the other. After exchanging semen, the two earthworms separate. When the eggs mature, the annulus secretes a viscous substance, which solidifies outside the annulus to form a ring-shaped mucus tube (earthworm cocoon). The mature eggs are discharged from the female genital pore into the earthworm cocoon. When the earthworms make a wave-like backward movement, the earthworm cocoon gradually moves forward accordingly. When it moves to the spermatheca pore, the sperm escapes and fertilizes in the cocoon. The earthworms continue to retreat, and finally the earthworm cocoon leaves the body, with both ends closed and left in the soil. Each earthworm cocoon has 1 to 3 embryos, which hatch within 2 to 3 weeks. If the environment is not suitable, the hatching can be delayed until the spring of the following year. [Edit this paragraph] Earthworms and flower pots. If there are earthworms in the flower pots, they must be killed. Flower pots are placed outdoors in the ground, and earthworms can easily drill into the pots through the bottom holes of the pots. Earthworms are beneficial in the fields, but they are harmful in flower pots. There is little soil in the flower pots, which will cause earthworms to gnaw the roots of flowers. Earthworms will also dig holes. Once watered, the water will flow away through the holes, and the flowers will not be able to drink water. If there are earthworms in the flower pots, you can go to the flower shop to buy some "trichlorfon" (pesticide) powder, sprinkle it on the surface of the pot soil, mix it with the soil, and water it. Trichlorfon can completely kill earthworms. Use according to the instructions on the package. Some people also believe that earthworm feces is a kind of fertilizer for flowers and is beneficial to flowers.

Earthworms are an important indicator of soil health

Earthworm feces are rich in inorganic salts such as nitrogen, phosphorus, and potassium, which can increase soil organic matter and improve soil structure. They can also neutralize acidic or alkaline soils, increase phosphorus and other quick-acting components, and make the soil suitable for the growth of crops. If the earthworms disappear from the farmland, the soil health index will be very poor. This is because earthworms can not only loosen the soil, increase soil fertility, but also improve soil structure.

Earthworms are soil fertility converters and are organisms that symbolize the quality of soil. The absence of earthworms in farmland means that there is something wrong with the soil! Have you ever noticed that you haven't seen earthworms in the soil for a long time?

Earthworms breathe through their moist body walls. After a heavy rain, the ground is flooded and the rain squeezes out the oxygen in the cracks of the soil. The oxygen in the soil is reduced and the earthworms cannot breathe in the soil. In order to breathe, the earthworms come out of the ground. The activities of earthworms in the soil can loosen the soil, increase the oxygen in the soil, and facilitate the breathing and growth of the root system.

Why can't we see earthworms in farmland now?

Since the 1950s, crop fertilization has mainly relied on chemical fertilizers. As we have long focused on increasing crop yields per unit area, we have used a large amount of chemical fertilizers, pesticides and insecticides, which has caused the deterioration of soil physical and chemical properties, the decline of soil fertility, accelerated topsoil erosion, soil compaction, and the deterioration of chemical properties (soil acidification, soil salinization, loss of soil fertility, etc.), which has caused the destruction of the living environment of earthworms in the soil, leading to the reduction or extinction of earthworms. The reduction of earthworms can mean that the soil ecology is destroyed and the soil quality is reduced!

The soil cannot do without it

The roles of earthworms in the ecosystem are: consumers, decomposers and regulators.

Earthworms can break up, decompose and mix organic matter. The feeding activity of earthworms strengthens the biological process of decomposition of plant residues, and the earthworm castings rich in easily hydrolyzed nitrogen accelerate the mineralization process of surrounding litter.

The activities of earthworms can change the spatial distribution of soil organic matter, making it distributed in patches, and can mix the organic matter with mineral soil to form soil particles rich in organic matter.

Earthworms can increase the levels of available nitrogen and phosphorus in the soil. Earthworm activity can increase the concentration of mineralized nitrogen in the soil because earthworms consume a large number of soil microorganisms, accelerating the mineralization and turnover of microbial tissues.

The burrowing behavior and feeding preferences of earthworms are closely related to the characteristics of soil organic phosphorus sources. The activities of earthworms facilitate the downward movement of phosphorus, improve the patchy distribution of phosphorus in the soil, and at the same time can significantly change the state of phosphorus, such as solubility, organic phosphorus pool, and alkaline phosphatase activity, in "hot spot" areas such as earthworm castings or caves.

Effects on soil physical and chemical properties

Earthworms have a significant impact on soil structure, aggregate formation, and the physical conditions required for plant growth and nutrient absorption. Earthworms affect soil structure primarily through their excrement and pores, which promote soil aggregation and make it easier for air and water to reach plant roots.

The activities of earthworms can also affect soil pH, redox state, soil temperature and other soil regulating factors. For example, the pH value of earthworm excrement is significantly higher than that of the surrounding soil, which can play a certain regulatory role.

Effects on plants, microorganisms and other animals

Impact on plants: Earthworms have an important impact on the available nitrogen and phosphorus in the soil, can promote plant growth, and may also cause changes in chemical substances in plants, thereby affecting the interaction between plants and other organisms. They have a significant impact on the dispersal and burial of plant seeds, as well as the recovery and spatial distribution of plant seedlings.

Impact on microorganisms: In the soil with earthworms, the total amount of microorganisms decreases, while the available nutrients increase. Moreover, after passing through the earthworms' intestines, although the total amount of microorganisms decreases, the biomass of active microorganisms increases.

Impacts on other soil organisms: Earthworm activity often benefits other soil animals, for example, it can affect the abundance and diversity of springtails in a variety of ways. Earthworms can change the structure of nematode communities in many ways, such as directly feeding on nematodes in soil and litter, or indirectly through vermicompost. There are almost no plant-parasitic nematodes in vermicompost, but the proportion of bacteria-feeding nematodes is significantly increased.

In addition: earthworm manure contains 1.4%, 1% and 1% nitrogen, phosphorus and potassium respectively, 46% humic acid, 23 kinds of amino acids, rich earthworm protease, and 105×8 beneficial microorganisms per gram of earthworm manure (only 105-106 in aged soil), and has the characteristics of uniform particles, breathable and water-retaining, odorless and hygienic, and lasting fertilizer effect. 20 cm thick earthworm manure with 85% water content can still reach 45% water content after 15 days in the hot summer, greatly enhancing the drought resistance of the soil. The earthworm enzyme in earthworm manure can also kill viruses, harmful bacteria and substances that inhibit plant growth in the soil. Earthworm manure is an ideal natural biofertilizer. In addition, earthworms can also degrade and evacuate pollutants in the soil.

It is a bug that has evolved over a long period of time.

Animals, fertile fields and garbage dumps are plentiful