The importance of arachnids in nature and human life

Spiders amaze with their persistence and hard work. They can be found in almost every corner of the planet. Spiders may not look very attractive, but they are an important part of the ecosystem. Most arachnids are predators, but they can also become prey for other animals. Experienced summer residents know the importance of arachnids in nature and human life, because these creatures help fight pests.

Useful properties of arachnids

Representatives of the class have a number of useful properties:

being predators, they destroy insects that can harm agriculture;
These animals themselves are also a link in the food chain. Spiders, ticks and other orders are prey for small mammals, toads, birds, lizards and other vertebrates;
mites that live in soil participate in soil formation processes;
Tick venom is used in medicines;

Pharmacists use the venom of arachnids to make sleeping pills and sedatives.

people weave fabrics from the webs of some spiders;

Fig.1.
Golden silk from spider webs People have learned to use spider web threads in weaving. In Fig. 1 you can see golden silk from the web of Madagascar spiders.

scorpions and spiders are used to prepare various dishes in Asian countries and China;

Fig.2. Dishes made from arachnids

spiders catch their victims on the web, thereby regulating the number of insects;

Fig.3. Web Hunt

By feeding on plant remains, earth mites fertilize the soil.

The purpose of spiders in nature

Surely in childhood, each of us felt a pang of pity, watching how a moth desperately fought in a tenacious web, and wondered why spiders are needed and what benefit they could have.

Even in the famous fairy tale “The Cluttering Fly,” the spider is presented as a notorious villain, and the fly as an innocent, unfortunate victim. However, in nature everything is much more complicated.

Beautiful, white butterflies with black dots that flutter over the beds in summer are cabbage butterflies that infect the cruciferous crop.

A cute light-colored moth, a whitefly, damages plant leaves and lays numerous offspring . These and many other harmful insects could have multiplied many times over if their numbers had not been controlled by spiders.

In fact, even a fly is not nearly as harmless as it might seem at first glance. Scientists have discovered several tens of thousands of pathogenic microbes on its paws.

And this insect reproduces at cosmic speed. The fly lives for about a month, during which time one female manages to lay about 3,000 eggs, which can bring new offspring within a few days.

It is easy to imagine the benefits spiders bring by controlling the number of flies in nature.

This predator spreads its web daily in the grass, as well as between tree branches. There are cases where several hundred insects got into the net every day.

However, even if you do not take into account such records, the benefits of spiders are obvious. Let not a hundred, but only 2-3 flies fall into one web. Then a hundred predators will destroy about 10 thousand harmful insects in a month.

In fact, there are many more spiders. According to scientists, more than 1 million individuals can live in an area of 1 hectare.

The benefits of these predators are enormous. Every day a spider is able to eat as much as it weighs. The diet of an adult consists not only of flies, but also of other parasites that can cause damage to fields, forests, and meadows.

Dangerous properties of arachnids

Despite the large number of beneficial properties, we should not forget that many arachnids are dangerous to human life and health.

For example, the karakurt spider, which lives in southern Europe and Asian countries, is dangerous for animals (deadly for horses and camels). It poses the same danger to humans, especially to children’s bodies.

Scorpion venom causes swelling, redness of the bite site, nausea and convulsions.

general characteristics

The word "arachnid" comes from the Greek word "Arachne", which in mythology was the name of a skilled weaver who challenged Athena, the goddess of wisdom, arts and crafts. This impudence led to her turning into a spider. The classification of arachnids, of which there are approximately 100,000 species, covers a significant range of subgroups. There are currently about 11 orders and 3 extinct.

Almost all adult arachnids have eight legs, although the front pair may be modified in some species. In addition, all have two additional pairs of appendages - pedipalps (which look a bit like hands) and chelicerae, adapted for nutrition, protection and sensory perception. Their body consists of two parts : the cephalothorax and the abdominal cavity. In addition to having an exoskeleton, arachnids have an internal structure of cartilaginous tissue to which certain muscle groups are attached.

Ticks, like spiders, have bodies divided into two parts. Unlike other arachnids, the first go through four stages of development: egg, larva, nymph and adult. Their size varies from 0.08 to 20 mm.

Ticks are known to be external parasites that feed on the blood of mammals, birds, and sometimes reptiles and amphibians. They are found throughout the world, but tend to thrive in warm, humid climates because they require a certain amount of moisture to metamorphose.

Arachnids are primarily terrestrial, although some are aquatic, and can be found everywhere except in extremely cold places such as the Far North and Antarctica. They range in size from the mite (about 0.08 mm in length) to the black scorpion of Africa (about 21 cm in length). As arachnids grow, they molt several times. Arachnids are primarily carnivores, but since most are unable to digest food internally, they inject digestive fluids into their prey and then suck out the liquefied remains. Number of known species:

40,000 - spiders;
32,000 - ticks;
6300 - haymakers;
2000 - Scorpios;
just over 3000 are false scorpions.

Most arachnids are harmless and only hunt insects. However, there are several species that are potentially dangerous to humans. Globally, 47 arachnid species are assessed as critically endangered.

What happens if you kill a spider?

If you kill an insect intentionally , then, according to the sign, troubles and problems in business await you.

Killed a little spider ? – problems in your personal life and bad news regarding children may appear. Moreover, if you believe it, then the smaller the creature killed, the more terrible the punishment for its intentional killing.

If a spider runs towards a person, it is considered to bring good luck. If you kill this messenger, you may run into trouble.

By killing a spider with a rolled up newspaper or a slipper , a person refuses good news. After this, he will not have access to information that could change his life for the better.

Causes of spiders

There can be many reasons why spiders settle in close proximity to humans.

In most cases, they appear in residential premises due to the following factors:

Accidental introduction of individual individuals from the street , for example, on shoes or clothing.
Independent entry into the house through open doors , windows or various cracks.
Availability of places in the house with ideal conditions for their living. Most often they are closets, attics or basements, since these are quite dark rooms in which people rarely visit.
The presence in the house of a large amount of food for spiders in the form of various insects. This is usually indicated by the presence of a significant number of these arthropods in the house.

Anatomical features of spiders

Each species has its own structural features of the body, legs, and location of the eyes. But there is a common characteristic common to all representatives of arachnids.

Body structure

The body of arthropods is divided into two main sections - the cephalothorax and abdomen. The first is divided by a transverse stripe; upon close examination, you can see the junction of the head and chest. The abdomen is attached to the cephalothorax with the help of a thin stalk.

The first two pairs of limbs, which in science are called chelicerae and pedipalps, are attached to the head part. At the tip of the first two limbs there is a small pointed sting, from which poison comes out if the representative is poisonous.

Scorpios: should you be afraid of them?

Don't be surprised that scorpions are also arachnids. Scientists have determined that this is the most ancient order of arthropods on planet Earth. Nowadays there are about one and a half thousand different species. The home of scorpions is the Himalayan heights and caves that go down to 900 meters; they live in tropical jungles, in the forests of Europe and even on the seashore.

The largest type of scorpion is the imperial scorpion, a representative of which can grow up to 20 cm in length.

The importance of arachnids in nature and human life is great, even if we do not see any direct benefit. Scorpions are dangerous and quite ferocious; they are especially active at night in the heat, their body picks up any fluctuation in the wind. Thanks to sensitive receptors, they can feel the touch of their future prey to the sand from a distance of about 30 cm.

If it suddenly turns out that the proposed dinner does not suit him, the scorpio takes a belligerent position to scare away the would-be victim. But when the creature satisfies the scorpion, it grabs it with its claws and hits it with its sting. For this purpose, its tail acquires an arc-like structure. The importance of the scorpion arachnid in nature and human life is determined as part of the food chain.

It does not help people get rid of garden pests, but it supports the theory of natural selection on the planet. Once the poison enters the body, it becomes paralyzed and all organs gradually cease to function.

Scorpios are individual farmers, they will never share their prey, and even in too difficult conditions, if a fellow animal is nearby, they can kill him and eat him. Despite this, these arachnid creatures can maintain the body in starvation for two years, including the absence of water. But they quickly gorge themselves, having eaten bloodworms on both cheeks, they can continue to walk around well-fed for several months.

The rumor that there are non-venomous scorpions is false. Absolutely all individuals emit poison, it’s just that the degree of toxicity varies from person to person. When a person is bitten, the poison immediately seeps into the blood, through which it reaches the nervous system, simultaneously contaminating the entire body with strong toxins. In fact, only twenty-five species are dangerous to humans. The most poisonous is the species that lives mainly in North Africa. For example, in Tunisia. It is called Palestinian, and about 90 percent of people who have poison in their bodies die from its bite. By the way, the lifespan of such an arachnid is up to twenty-five years.

Life cycle

The life cycle of individuals of different species is somewhat different, but has common features. Breathing is carried out using spiracles located on the lower part of the abdomen. From them, air enters the trachea and pulmonary sacs. Some representatives have a primitive respiratory system; air enters the body through holes located on the entire surface of the body.

The digestive system of individuals is designed to consume semi-liquid food. Consists of the esophagus, stomach, posterior lid, usually ending in the cloaca. In front of the cloaca there are excretory glands. Additionally, the secretion of waste products is carried out with the help of coxal glands.

Almost all spiders are predators. Small individuals feed on small insects and arthropods. Large representatives eat snakes, lizards, and frogs. In most cases, the predator stings the prey and injects poison inside through the wound. After 40-60 minutes, the insides of the prey turn into liquid pulp and the spider sucks it up.

All arachnids are heterosexual. Sexual dermographism is very pronounced. Males usually have a smaller body size and a dull color, unlike females.

Reproduction occurs in several stages:

The male shows the female his readiness to mate. Methods differ between species. Some touch the web, others make a special sound.
If the female is ready, she allows the male to approach. Using special bulbs located on the pedipalps, the male introduces seminal fluid into the female’s genitals.
After mating, the female often eats the male if he does not have time to escape.
After 60-75 days, the female lays eggs, and after 35 days the spiderlings appear. They stay close to their mother for some time, then scatter.

Sexual maturity in different species occurs at the age of 3-5 years. The lifespan of individuals differs. Males of most varieties live no longer than 3-6 years. Females can live up to 15 years. Some species of tarantulas live up to 25 years.

Why do people have a fear of spiders?

Arachnophobia is a “special” phobia. According to one hypothesis, it appeared during plague epidemics when people believed that spiders

carry the infection.
Since then, parents have instilled in their children an exaggerated fear of spiders
. According to statistics, a third of all women and a fifth of men suffer from arachnophobia.

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Internal structure

There is no complete circulatory system. Blood too. It is replaced by lymph. There are 3-4 holes in the heart, called ostia. Through the ostia, lymph from the animal's body enters the heart, and from there, through the arteries, the heart drives lymph into the spaces between the internal organs. From the spaces, lymph enters the pericardial region of the body and returns again to the heart. Lymph has a mechanism that additionally supplies the spider with oxygen.

Spider structure

The respiratory system has a peculiar appearance. The lung sacs have plates and look like books. The breathing holes that open the lungs are equipped with protective covers. There are also long tracheal tubes that transport oxygen from the openings to the organs of the spider's body.

Being a predator, the spider has a well-developed central nervous system and a significant brain volume. In the cephalothorax of the arthropod there are 2 nerve ganglia, from which many nerves diverge, leading to the organs of the spider. These nodes are the brain of the animal.

Distribution and habitat

Spider in the forests of Russia Spiders live on all continents except Antarctica.
Being invertebrate animals, they cannot control their body temperature and are susceptible to cold, however, in northern Canada, Greenland and northern Russia they get along well. They are one of the few species of animals that get along well in the highlands. There are certain species that feel great even in an aquatic environment.

The main factor that limits their habitat is the availability of food.

What benefits do spiders bring?

Let's start with the fact that the vast majority of spiders that can be found in our apartments are absolutely harmless to humans. Yes, they have poison - all spiders are poisonous. But this poison is not designed for human metabolism, so it will not lead to any health problems.

But it works very well for the numerous insects that inhabit our apartments with us. Especially on mosquitoes and flies, which are real pests and causes of major health problems.

Journalist Artyom Kostin from the team recalls that during his stay in the village, no one touched the spiders there at all, and practically no cobwebs were removed. Especially in those places where the presence of flies and moths could really harm stocks. The most banal village ingenuity - why put in the effort and somehow ward off flies if spiders can do this job themselves just fine?

There is a belief that some spiders specifically climb into a person’s natural openings while he sleeps. And that in a lifetime a person can swallow about 10 spiders. This fact in itself scares many, but there is no reason to panic. Because there are no spiders that lay their eggs in humans. There are no spiders that can withstand gastric juice and somehow harm the mucous membrane. So even if you accidentally swallow a spider, then it’s a spider’s problem. Plus, spiders are not intermediate or definitive hosts of any parasites that are potentially dangerous to humans.

Where do spiders go in winter?

Arthropods adapt to the onset of cold weather in different ways. Spiders are unable to tolerate temperatures below 0 degrees due to tissue crystallization. Depending on this, spiders can sleep or die in winter.

Young cross spiders and “newborn” wasp spiders migrate on wind-blown spider webs in search of habitat on warm September days. Huddled in a crack in the bark of a tree, spiders sleep in winter.

Sexually mature parents of baby wasps end their life in the summer: the male - in the form of a “wife” dinner after mating, the female - after laying eggs. A similar situation occurs in adult crosses. Autumn is the mating season, when males go in search of females sitting in their web. After fertilization of the female, the male dies. The spider weaves a cocoon in which it lays eggs. Having hidden it in a secluded place (in the bark of trees, cracks in masonry), it also dies. In the spring, spiderlings emerge from the eggs, ready to weave webs.

Males and females of black widows do not survive until the cold weather. At the end of June, mating occurs, after which the female eats the “suitor”. Having laid up to 130 eggs in prepared cocoons, she hides them in lairs (mouse holes, crevices) entwined with dense cobwebs and dies. Spiders appear in September and live in a cocoon until April, eating each other. With the onset of stable heat, they go outside.

As for the species of black widows, spiders that were born in September spend the winter with them. In a warm cocoon left by a caring spider mother, they sleep until April. Spreading in search of habitats, they have arachnoid and venom-carrying apparatus. During mating at the end of June, the female karakurt eats the male. After laying eggs it dies.

Domestic arthropods may go into torpor with the onset of winter if the number of indoor parasites decreases sharply. Waking up before the onset of spring, they can feed on their relatives.

Rare species live in burrows and crevices

Predatory arthropods, whose life cycle exceeds a year, fall into torpor with the onset of cold weather. Species such as tarantulas live in the wild for 5 to 10 years. Helping them survive is the ability to go without food for a long time and the mild climate in their habitats. With the onset of cold weather, they burrow into their vertical burrows and hibernate until spring.

The edge hunter has a life expectancy of 2 years, until the age of mating. After breeding, they die in August. Immature individuals spend two winters in the mother's cocoon, attached to the grass on the shore, in a state of torpor.

Silverback spiders build their winter cocoons underwater

During the cold season, when rivers and lakes are frozen, the silverfish prepares winter housing. The spider controls the volume of the bell and the oxygen content in it. The air supply in such a cocoon is enough for 4-5 months. Nearby, the silverfish weaves the second and third mesh networks and fills them with air. This insurance allows you to overwinter without rising to the surface until warm days arrive.

Hiding in a mollusk shell

If there is no algae and nowhere to go, the water spider can use an abandoned mollusk shell instead of a cocoon. He fills it with air bubbles from the surface and covers it with thick nets instead of curtains. Such a house serves as reliable protection from large fish and crayfish.

They overwinter with young offspring (the female is eaten in the spring)

The black fathead spends its winter in a special way. With the onset of autumn, the mating period approaches, and the males go in search of females. Having carried out the necessary fertilization ritual, the male remains to live in the same burrow with the female. The fathead spider makes a cocoon for its offspring, where it soon lays eggs.

For 2 months, spiders guard the clutch in a cocoon. With the onset of spring, spiders appear. Spiders serve as food for them. By the end of summer there are 3 molts. Young spiders crawl out of their holes to find a home. After 2 moults they will become sexually mature and will look for a female. A male spider, whose life cycle is less than a year, dies by this time.

Lacquer bug

Relatives of cochineal scalebugs are varnish scalebugs. They produce shellac resin, which is used in the paint and varnish industry. Also, this connection does not conduct electricity, therefore it is used in electrical engineering as an insulating material. However, contrary to the name, real shellac is not currently used to cover nails.

Shellac in products is designated as food additive E-904

In addition, the substance is edible; it can be used to coat tablets and candies.

Insects are part of nature; without them, the Earth's ecosystem could not exist. But even on a smaller scale, some of these creatures bring benefits to humans, and quite tangible ones.

Reasons for appearing in the apartment

The main reason for the appearance of arthropods in a human home is the availability of food. Suitable living conditions are also important:

Many predators can be seen in the house in the autumn. They are attracted by the favorable temperature, because the apartment is warmer than outside.
Depending on the type of arthropod, it can be seen both in dry and wet places. The level of air humidity also affects the choice of habitat - heat-loving spiders settle in the kitchen and bedroom, while lovers of cold and dampness prefer to live in the basement or bathroom.
Insects most often appear in rooms where cleaning is rarely carried out. It is in such rooms that arthropods actively breed and feed.

Predators enter a house from the street and stay there if living conditions are favorable. If there is no food, the spider leaves the home and goes in search of a new one. The most likely places for arthropods to enter an apartment:

furniture stored outdoors for a long time;
garden or wild flowers, herbs brought into the house;
Street clothes;
open windows, doors and cracks in the floors and walls.

Folk remedies against spiders

In addition to industrial chemicals, some folk remedies can also be used to combat arachnids in an apartment. These measures do not have scientific confirmation, but they are quite simple and give the desired effect.

It has long been noted that spiders do not like strong odors and live in dry and warm rooms. Therefore, the following control methods can be used.

Hazelnuts, chestnuts, and Osage oranges are believed to repel spiders with their scent. The above fruits can be broken or crushed to release the odor and placed in areas where arthropods congregate.
Spiders cannot stand the smell of peppermint. You can add a few drops to a spray bottle and spray around the apartment. Such aromatic procedures should be carried out regularly. You can also try tea tree or eucalyptus oil. They also have a fairly pungent odor that will repel spiders.
To combat, you can use diatomaceous earth, which is scattered in a thin layer along the baseboards around the perimeter of the room. Crossing such an embankment, the spider is cut into two parts and dies very quickly.
Vinegar is also a good repellent for these animals. You can spray it around the room or place it in the corners of a saucer with water and a few drops of acid.

Why do they keep insects and spiders?

12/19/2016, 3:00 pm Insects and spiders can be very interesting to watch. These are silent and non-littering pets that do not require much space. In addition, they do not need attention and communication (in fact, the less attention you pay to them, the better they feel). However, before you decide to keep an insect or spider, think about the reasons why you want to keep it in your home. Whether you just want to impress your friends, or want a unique, "cool" pet, think again. Insects and spiders are truly unusual, and although they are quite unpretentious, the owners still take on certain responsibilities. Too many people tend to buy pets on the spur of the moment, and when the novelty wears off, they become bored with caring for a pet.