A message on the topic of the diversity of arachnids. The variety of arachnids and their importance in nature and human life. General characteristics of arachnids. Ticks: importance in the life of arachnids

Scorpions are the most ancient arthropods that came to land from the sea. More than 400 million years ago they lived in the waters of the oceans. Their size then reached one meter in length. After landfall, they shrank, but what is striking is that their shape remained the same. Scorpions are an interesting object for research, but they began to be studied in detail only in late XIX century. Scientists still do not get tired of being surprised at how many secrets and mysteries this animal keeps.

There were legends about the habits of this "evil creature". Images of scorpions penetrated magic and astrology very early. They are present among the oldest Babylonian calendar drawings. Around 1150 B.C. e. in the circle of zodiac figures appears the scorpion man. Among the ancient Egyptians, the goddess Serket was considered the mistress of scorpions. She was depicted with the head of a scorpion or with human head but with a scorpion seated on it. These animals were painted on tombs, and the first Egyptian king to go down in history was the pharaoh or king Scorpio, who is reported in the Book of the Dead.

They were also well known to the ancient Romans and Greeks. So, the Romans had battle badges with the image of a scorpion, which is closely related to astrological beliefs. At that time, it was believed that the founders and destroyers of cities are born when a scorpion raises its sting above the horizon. The emperor and brilliant commander Tiberius was born under this sign.

One of the zodiac constellations. ancient greek myth says: Poseidon had a son - the legendary hunter Orion. Puffed up, he declared that he had no equal in this world, and he would kill any animal he met on the way. Before Orion had time to utter these words, an inconspicuous and inconspicuous scorpion approached his feet. He lifted his sting and stung the brave and boaster, poisoning him with his poison. The gods of Olympus were frightened by Orion's boasting and therefore rejoiced at his death. In gratitude, the scorpion was transferred to the sky and placed among the constellations of the Zodiac. Since then, to this day, Orion has been hiding from his killer. As soon as the constellation Scorpio appears in the sky, Orion disappears over the horizon. It was believed that the constellation Scorpio brings bad luck. With his appearance, autumn came to the sky: the earth was fettered by cold, rains and storms mercilessly whipped it, and wars devastated, exterminated and burned all life. According to ancient beliefs, a scorpion that appeared in a dream foreshadowed evil. At the same time, he protected from the evil eye and other troubles. Byzantine legend says that in ancient Amasia, located in the east of Asia Minor, there was a talisman in the form of a scorpion. He guarded the city from other poisonous animals and their relatives. In Africa, Persia, the Levant, scorpions were a real disaster. Even if they did not attack people, despite strict religious prohibitions, the Jews were allowed to kill scorpions on Saturdays. These animals were an invariable attribute in the experiments of sorcerers and alchemists. With their help, they tried to create various magical potions, and even gold. In the Christian religion, scorpions are typical inhabitants of the underworld.

Scorpions are not only the oldest terrestrial arthropods, but also the oldest among all animals living on Earth. Scientists have singled out these primitive arachnids into an independent class. At present, the area of ​​​​distribution of scorpions encircles Earth approximately between 50 degrees north and south latitude. IN old times, until the end of the Tertiary period, when the climate was warmer and moist forests extended to high latitudes, these animals were found on most of the land. Now there are about 1500 species and up to 800 varieties of scorpions. They live almost everywhere. They can be found in the snows of the Himalayas at an altitude of up to 5000 m, in caves at a depth of up to 800 m, in deserts and tropics, in European forests, on the shores of the seas.

In Ukraine, scorpions live in the Crimea, they were also found in the Odessa region.

Scorpions have sizes from 5 to 10 cm, some species reach a length of 20 cm. The largest is the tropical emperor scorpion that lives in Equatorial Guinea. An adult can reach a length of 8 cm. Once a specimen was found 29 cm long, counting from the tips of the claws to the tip of the sting. The smallest animals reach a size of 1.2-1.3 cm. Scientists have at their disposal ancient remains of animals up to 40 cm long.

Scorpions are ferocious predators. They usually go hunting at night, and are especially active in hot weather. They are very sensitive to all touches, vibrations of air and earth. Special receptors accurately capture odors. Scorpions feel another creature at a distance of 20-50 cm. If the prey is unsuitable, the animal assumes a threatening posture: it abruptly bends its "tail" over the cephalothorax and swings it from side to side. Well, if the victim is edible, the scorpion grabs it with its claws and stings with the tip of the tail, where it has poison. If the victim resists, he receives additional injections. At the same time, she is immobilized and dies from the poison. Scorpions eat only live prey, prefer to avoid relatives and not share with them. Here they show a rare individualism. When keeping scorpions in captivity and cramped containers, they attack their relatives and can eat each other. The ability of scorpions to almost never lose water remains a mystery. These animals almost never drink, but take moisture from food. Their body is adapted to absorb and process what they eat. In this case, the scorpion is the champion: 70% of the food consumed replenishes the tissues of its body. In poor conditions, animals "fast" for 6-7 months. They can starve from one to two years! This is surprising, but true: after eating one moth, a scorpion may not eat for several months. The poison is produced by all scorpions, but the degree of its toxicity varies among different types. When bitten, the venom destroys blood cells and has toxic effect on nervous system and the passage of nerve impulses. From 1500 known to science only about 25 species of scorpions are especially dangerous for humans. The most poisonous in the world is the Palestinian scorpion, which accounts for 80% of all stung and 90% dead people V North Africa(Tunisia). Its venom is equal in strength to that of a cobra. In 1946, 1933 people died in Mexico from the sting of scorpions. Until now, in this country, from 800 to 1000 people become victims of this predator every year.

They live from 8 to 25 years. This is a record for arachnids and insects. The breeding biology of scorpions is very peculiar. Mating is preceded by a "nuptial walk". For many hours, and sometimes for days, they walk, grappling with claws and raising their "tails", the female and the male. Then the male drags his chosen one to a secluded place. The most striking thing is that these arthropods are mostly viviparous. Pregnancy in a female can last from three to 18 months. This is more than many mammals. As a rule, up to 25 scorpions are born. They climb onto their mother's back and sit there for about 10 days. The female scorpion is a very caring mother, which increases survival and accelerates the growth of offspring. She catches the prey, tears it into pieces and feeds it to the kids. She also makes sure that the children do not eat each other. It is amazing, but true: scorpions, isolated for a while and then planted with several females, unmistakably recognize their mother. To become adults, scorpions go through seven molts, reaching the age of one and a half years. From the scorpion-dad at this time there is little sense. He does not bring up cubs, but he does not suffer from appetite either. short-lived love story for 20% of males it ends tragically. Most large females sting their lover and then eat him.

There are many legends and fables about the "imaginary suicide" of scorpions. For example, one of them says: if you surround it with burning coals, then in order to avoid painful death, he allegedly pierces himself with a stinger and dies. Scientists have proven that scorpions' own poison is not dangerous. The fact is that under the influence of strong stimuli, they are able to fall into a stationary state. In science, this phenomenon is called catalepsy, or thanatosis. Having darted around in a fiery circle, the animal raises its "tail" vertically and freezes. This picture is taken for "suicide". But after a while, the scorpion "comes to life" and, if nothing threatens him, quickly crawls away.

Scientists are amazed by this fact. For orientation at night, a scorpion needs a very weak glow of stars. Studies have shown that no animal is as sensitive to light. Not to mention one more mysterious feature scorpions. Their survivability is simply amazing: only they are able to tolerate very large doses of radiation without any harm - a thousand or more roentgens! During the test of the French atomic bomb in the Sahara desert, only scorpions survived in this hell. There is something to think about! And at the same time pay tribute to the heroism of these little creatures. After all, scorpions, with their amazing ability to overcome difficulties and a thirst for survival, cause not only surprise, but also respect, as a symbol of perseverance.

The importance of arachnids in nature and human life is difficult to overestimate. After all, they are an important element in the food chain, regulate the number of many species of insects, and some can even be deadly. The importance of arachnids in nature and human life will be briefly outlined in our article.

Characteristic features of the structure of arachnids

But first, let's figure out by what signs animal organisms are attributed to this systematic unit.

These are representatives of the arthropod type, whose body consists of a cephalothorax and abdomen. On the first of them there are six pairs of limbs - these are chelicerae, with the help of which arachnids pierce the victim's body. There are also tentacles and four pairs of walking legs. These animals lack antennae. There are no limbs on the abdomen, but they can be modified into arachnoid warts or lung sacs. Structural features determine what is the importance of arachnids in nature.

What is a web

The predominant number of arachnids is able to build trapping nets from a special substance found in special warts. They emit threads that, in their strength, can even be compared with steel wire. The web pattern is characteristic of each species. On spirally twisted threads there are drops of sticky liquid. If an insect gets into it, then it has little chance of getting out. In addition to the trapping net, dwellings and cocoons are made from this substance. The value of arachnids in nature and human life is also determined by the method of nutrition.

predator spiders

All types of spiders are predators, but their methods of hunting are completely different. To get a victim, it is not necessary to lie in wait and pounce on it, like jumping spiders. Many species use trapping net. Once in it, the insect tries to escape. At the same time, the threads of the web begin to oscillate. One of them is always attached to the predator's limb. It only remains for him to approach the victim and kill her.

The importance of arachnids in nature and human life is also determined by the method of digestion. They can only eat liquid food. Through the hole that the spider makes in the body of the victim with the help of chelicerae, he injects digestive enzymes inside. After a certain period of time, the spider pumps already digested contents into its intestines with the help of its own sucking stomach.

A tarantula can also be dangerous for a person. Their venom causes severe pain throughout the body, trembling and loss of consciousness. In this state, a person needs to inject a special serum, and burn the bite with a match to stop the spread of toxins.

The value of arachnids in nature and human life

It is worth noting that predatory spiders never attack a person in order to profit. They do it for protection. But their venom can be deadly. However, most often spiders prey on small inhabitants of water bodies and insects. Destroying the latter, they thereby regulate their numbers. Thus the number of blood-sucking agriculture is reduced. This certainly determines positive value arachnids in nature and human life. Spider venom is a raw material for the production of sleeping pills and sedatives. medicines. To obtain them, many types of spiders are bred artificially.

Ticks: importance in the life of arachnids

Modern taxonomy divides the class of arachnids into nine orders. The most common are spiders, ticks and scorpions. The importance of arachnids in the life of people and nature has different systematic categories of this type.

Everyone knows that walking through the forest belt in late spring and early summer can be dangerous. After all, it is during this period that ticks actively multiply and look for food sources. Their body consists of a fused cephalothorax and abdomen, and the head is formed by tentacles and chelicerae. Ticks are also distinguished from other arachnids by an indirect developmental cycle. This means that a larva with three pairs of legs develops from an egg, which eventually turns into four.

Habitat

The great importance of arachnids in nature and human life is also due to their wide distribution. It's not only woodlands, salt and fresh water bodies, soil, a variety of plants, the surface, as well as the body of animals and humans - all these environments are perfect for the nutrition and life of ticks.

The negative value of arachnids in the life of people and nature lies in the fact that many are causative agents of very dangerous diseases. Feeding on the blood of humans and animals, they can carry encephalitis, and dogs, relapsing fever.

Protection methods

To protect yourself from ticks, going for a walk, you need to cover the body with tight clothing and a hat. Returning home, look through all things, remove and destroy dangerous arachnids.

In order to prevent the development of a barn mite, it is necessary to monitor hygiene in the house, periodically change bed sheets, dry pillows and mattresses in the sun, more often carry out wet cleaning of the room.

scorpions

Scorpions are also prominent representatives of the arachnid class. Most of them live in tropical regions and in subtropical regions. On the back of their abdomen are glands containing a poisonous substance. The ducts of the toxic glands are opened with a needle that ends in the abdomen. The venom of scorpions is very dangerous for human health and sometimes life.

Benefit and harm

But, as they say, there is no evil without good. An important positive value of arachnids in nature and human life lies in their participation in soil formation processes. For example, being saprotrophs, they decompose dead organic matter. At the same time, the soil is enriched with nitrogen, which is so necessary for plants for the development of the root system. Destroying harmful insects and other arthropods, many types of mites help save crops cultivated plants prevent the spread of deadly diseases.

Thus, the value of arachnids in nature, human life is great, both negative and positive.

Spiders are very useful animals that exterminate harmful insects. We are people, we have bad habit disturb the life of the natural world for our own selfish needs. In doing so, we are destroying a lot of spider habitats. The use of insecticides in agriculture destroy entire settlements of insects and spiders. Very a large number of spiders are listed in the Red Book and are currently on the verge of extinction. It has become very rare to meet tarantulas in South America, due to the fact that they were caught and sold as pets. Nowadays, spider venom is increasingly used in medicine. Previously, they were caught in nature, now spiders are quite successfully bred in captivity. But the significance of spiders for humans is not limited to the use of their poison. People have long tried to unravel the secret of the web and make fabric from it. Someone even managed to create gloves and stockings from such a web fabric in a single copy.

Some people keep spiders in their homes as pets. Mostly non-poisonous tropical spiders become "domestic", and the tarantula is also very popular. They are kept in a small terrarium; for these purposes, an aquarium is quite suitable, which must be closed with a lid from above, leaving only small holes for air to enter.

The role of spiders is high both in the fields and in gardens and vineyards, where spiders eat leafworms, springtails, aphids, turtle bugs and other insects. It is important that spiders find pests not only on the ground, but also in the plant layer.
Despite the dislike of spiders that most people have, they still provide benefits. As predators, they reduce the number of smaller insects. Spiders serve as food for birds and other animals, especially certain types of wasps, which paralyze spiders and lay their eggs in the paralyzed body. Efforts to use spider silk for fabric were not economically successful, but silk was used for artificial hair, optical instruments. Although spiders have taken a place in various mythologies, their widespread disrepute in modern time probably due to their tendency to hide in dark places, their sudden appearance sometimes causes unreasonable fear.

The scabies mite settles on human skin and causes scabies. This disease can be prevented by keeping household items clean, observing hygiene rules. A serious disease is transmitted by blood-sucking ticks (taiga and village) - encephalitis, tick-borne typhus. The means of protection is clothing, and the prevention of disease is vaccination.

In the evolution of spiders, the web was crucial - spiders constantly use it. They interact with the outside world through their cobweb adaptations (they build nets, settle on cobwebs, etc.). And with all the great species diversity, spiders retain unity in the features of structure, nutrition, and development. Adapting to new conditions, they changed, first of all, their cobweb adaptations.