Why spiders are not insects. A spider is an insect or an animal

The flora and fauna of our planet is so diverse that it can be quite difficult to determine species affiliation creatures that live near humans. Sometimes individuals that look similar at first glance turn out to be representatives of different biological classes. This similarity gives rise to a lot of misconceptions. So, many people think that spiders are insects.

Many people mistakenly classify spiders as insects.

Basic concepts

Biologists classify living organisms according to their unifying characteristics. Animals are creatures that move from place to place on their own and do not produce their own food from raw materials in their habitat. Those that cannot move of their own accord, but have the ability to move by the forces of nature or in other ways, synthesize food from environment are considered plants.

Within the numerous kingdom of animals, organisms are distinguished that do not have a spine - invertebrates. Representatives of this group are mostly small in size. Some of them are land dwellers, and for some, water becomes a home. They are all very different - they crawl, wriggle, walk and even fly. Since everything in science must be structured, then scientists attributed insects and spiders to a separate type - arthropods, or arthropods.

The main difference from insects lies in the more complex arrangement of internal organs.

Among the huge number of invertebrates, more than a million different species have bodies with three main parts - the head, rib cage and belly. On the head are the eyes, antennae and mouthparts. Thoracic has three pairs of legs. The entire body is protected by a tough outer covering called an exoskeleton. Organisms that have these characteristics belong to the class of insects.

The other, smaller group has only two main body parts - a combined head and chest (cephalothorax) and abdomen. The cephalothorax contains eyes, mouthparts (without antennae), and four pairs of legs.

Animals that fit this description are grouped into the class of arachnids. It includes a spider, as well as a scorpion and a tick.

In this video you will learn about the structural features of spiders:dodo

Features of arachnids

Obviously, not all arachnids are the same. In representatives of this type of arthropods, biologists have found differences. A few main signs that spiders are not insects, and also have differences from other arachnids:

• the cephalothorax has no antenna, it has only 4 pairs of simple eyes, a pair of jaws and 2 pedipalps;
• in principle, they do not have wings;
• 4 pairs of articulated legs are attached to the cephalothorax;
• the abdomen is not segmented and is connected to the cephalothorax by a thin "waist";
• the body is covered with an exoskeleton, and sensory hairs grow from the skin.

Interestingly, spiders have claws located at the end of each limb.. The spider leg consists of seven segments: coke, skewer, femur, patella, shin and, finally, a tarsus, which may end in two or three small claws. Such features are necessary in order to help the animal cling to its web.

All 4 pairs of legs have muscles that attach to the inner wall of the cephalothorax and intestines. It's amazing, but that's exactly what internal structure helps the spider to suck out food. The circulatory system in these arthropods consists of a heart, arteries and veins, but does not have capillaries. The heart muscle has one cavity and with the help of valves distills blood in one direction. By the way, the color of spider blood is blue, it received such an unusual staining due to hemocyanin dissolved in the lymph.

Spiders (like insects and animals) have respiratory system, represented in these creatures by the trachea and lungs. The structure of the lung tissue, of course, is very different from the human respiratory organs. All families of arachnids do not have a muscular respiratory mechanism.

Silk nets

Almost all arachnids produce webs, but some do not weave webs from them. These protein filaments are used for climbing, hunting, breeding, defense and other needs of the animal. If you look at a frozen web, it may seem that it is monolithic, but in fact it can be 3-4 separate threads that stick together when dry.

Surprisingly, the webs are so strong that some spiders use them to travel.. One end of the thread is attached to a tree branch, and the animal hangs on the other end and sometimes moves for many kilometers with the help of the wind. Interestingly, the owner disposes of the unnecessary network - he simply eats it up.

Spiders treat insects as food, some large individuals are able to catch and eat even bats, small birds or small fish.

Representatives of the class of orb-weavers catch fish, weaving a semblance of a fishing net from a web. These creatures hunt prey in very different ways:

• spiders that live in holes jump out of them to catch a passing or flying victim;
• some, having placed sticky snares, sit in ambush on plants, tree bark, under stones and wait until the victim herself falls into their paws;
• more active individuals go in search of prey on their own.

All spiders are carnivores. Their digestion begins long before food enters the stomach. Some representatives inject enzymes directly into the body of the victim, others first break the food with their jaws. Partially digested food is absorbed into the intestines.

Disputes on the topic "are spiders insects, if not, why" arise to this day. Although there are huge differences between these groups of living organisms.

In fairness, it should be noted that until the middle of the last century, these classes were indeed united by one biological type.

From a scientific point of view, it is believed that spiders are animals that belong to the type of arthropods and the class of arachnids. About 42 thousand varieties of spiders can be found on the planet, including 1.1 thousand fossils. Spiders inhabit almost every corner the globe. They can be found in conditions where none creature cannot live. This type of predator feeds on insects, small animal species, as well as amphibians. Among the many varieties there are spiders that feed on the green part of plants. The science that studies the life of spiders is called arachnology.

Spiders: description

These small living creatures can be found everywhere, as in natural conditions, and in a person’s dwelling, in basements, attics, in various outbuildings. Often, because of their small size, spiders are called insects, but if you imagine that representatives of arachnids up to 35 cm in size are found in the tropics, then this is a mistake.

In fact, to be precise, spiders and insects represent animals belonging to the arthropod type. They differ only in classes and units. The answer to the question of what kind of living creatures spiders belong to is fundamentally wrong, since we can safely say that spiders are animals that represent a certain class.

To be clear! Many are accustomed to the fact that all sorts of insects are insects, and mammals are animals, which leads to some problems in determining these factors. Since the spider is distinguished by its characteristics of life, they were identified in separate class. The fact that a spider is not an insect is for sure.

The fact that spiders are defined in a separate class "arachnids" should not raise any questions. All animals of this class have a characteristic feature - their body is divided into 2 parts: the abdomen and the cephalothorax.

There is another difference that immediately catches your eye - this is the presence of 8 legs, instead of 6. Arachnids also have chelicerae, which are located in front of the cephalothorax, as well as tentacle-like pelipalps. As a rule, they are located on the sides, differ in size from the front paws, but perform the same functions: with the help of them, the spider holds its prey and moves.

It's important to know! Spiders belong to the class "arachnids" and represent a species of arthropods.

Spiders stand apart, as they have a number of characteristic differences that are not characteristic of other types of animals or insects in the concept that people have. These differences come down to certain forms of life activity, such as reproduction, nutrition, size, and so on. These differences are also characteristic of other representatives of this family, depending on the species or subspecies.

To characteristic features spiders should include:

• The body consists of two parts: the abdomen, various shapes, depending on the species and cephalothorax.
• The presence of 4 pairs of legs, 2 chelicerae and pelipalps is characteristic.
• Spiders don't have whiskers.
• Their feature is the weaving of a web for various purposes, and the pattern of the web can be unique.
• Spiders have poisonous glands, the poison of which paralyzes the victim.
• Spiders lead a solitary lifestyle. Most females, after fertilization, eat their chosen ones.

Arachnids can be found in almost all corners of our planet. There are also exotic species that are not dangerous to humans and are kept as pets.

Science also knows species that are dangerous to humans, since their bite can be fatal. As a rule, such species inhabit the tropics and other, hotter areas, such as the desert, for example. In our places poisonous spiders are extremely rare. The main types of spiders are real orderlies who fight daily with many insects that are sometimes dangerous to humans. Naturally, the appearance of spiders in a person's home is perceived extremely negatively by family members. This negative reaction is exacerbated by the intimidating appearance spiders, but in fact, most of the species are practically harmless to others.

The first spiders appeared about 400 million years ago. They are descended from a crab-like ancestor. To date, there are more than 40 thousand species of spiders.

Many people believe that spiders are insects. In fact, spiders are a separate order and class - arachnids (Arachnida, chelicera subtype - Chelicerata, arthropod type. Noticeably different from insects.

First of all, it is worth noting that spiders do not have 6 legs, but 8. In front there are special limbs with poisonous claws - chelicerae. However, in middle lane Russia has not registered the presence of deadly spiders for humans. From a big bite.
The spider can be felt except for burning, fever and pain. The first spiders will not attack. If a medium-sized spider accidentally falls from the web onto a person, then you should carefully blow it off, and not beat it - otherwise it may get scared and bite.

Spiders usually have three pairs of spider warts on their abdomens. Digestion in these arthropods is extraintestinal. Unlike, for example, predatory praying mantises, chewing the caught fly with appetite, the spider injects digestive enzymes into it, which transforms them.
The insect in the "Soup" after a few hours, after which it sucks out the contents. Spiders have a very strong web, if an airplane crashes into a pencil-thick web, it will not break.

Why a spider is not an insect for class 1.

First of all, it is worth noting that spiders do not have 6 legs, but 8. In front there are special limbs with poisonous claws - chelicerae. However, in Central Russia, the presence of deadly spiders for humans has not been registered. From a big bite
a spider can be felt except for burning, fever and pain. The first spiders will not attack. If a medium-sized spider accidentally falls from the web onto a person, then you should carefully blow it off, and not beat it - otherwise it may get scared and bite.

Spiders usually have three pairs of spider warts on their abdomens. Digestion in these arthropods is extraintestinal. Unlike, for example, predatory praying mantises, which chew the caught fly with appetite, the spider injects digestive enzymes into it, which turn
the insect into the "soup" after a few hours, after which it sucks out the contents. Spiders have a very strong web, if an airplane crashes into a pencil-thick web, it will not break.

The first thing that catches your eye when meeting insects is their long constantly moving whiskers (antennas). Spiders do not have antennae. Their eyes are also simpler, but there are many of them - most often eight. The body is covered with an external skeleton (exoskeleton). It consists of a cephalothorax and abdomen, connected by a stalk.

The first spiders appeared about 400 million years ago. They descended from a crab-like ancestor. To date, there are more than 40 thousand species of spiders.

Many people believe that spiders are insects. In fact, spiders are a separate order and class - arachnids (Arachnida, subtype Cheliceraceae - Chelicerata, type Arthropods). Markedly different from insects.

First of all, it is worth noting that spiders do not have 6 legs, but 8. In front there are special limbs with poisonous claws - chelicerae. However, in Central Russia, the presence of deadly for people has not been registered. From the bite of a large spider, you can only feel a burning sensation, fever and pain. The first spiders will not attack. If a medium-sized spider accidentally falls from the web onto a person, then you should carefully blow it off, and not beat it - otherwise it may get scared and bite.

Spiders usually have three pairs of spider warts on their abdomens. Digestion in these arthropods is extraintestinal. Unlike, for example, predatory praying mantises, chewing a caught fly with appetite, the spider injects digestive enzymes into it, turning the insect into a “soup” after a few hours, after which it sucks out the contents. Spiders have a very strong web, if an airplane crashes into a pencil-thick web, it will not break.

Spiders usually have 8 eyes, sometimes 6, or very rarely 2. Males have bulbs on their forelimbs, into which they place sperm to fertilize the female. Some males are already ready for death after mating - they allow the female to eat themselves, others intend to fight for their lives and seek to escape. In any case, males do not live long, but females need to raise offspring, so they live longer. Males are smaller, females are huge. Many females are caring mothers. They weave a ball-cocoon from a web and carry spiders in it.

Almost all spiders are predators. The exception is Kipling's Bagheera spider (Bagheera kiplingi). Biologists have discovered this jumping spider in the forests Central America, On The Branches Of Acacia. Spiders live on acacia along with ants. Ants guard these trees for Belt's nutrient bodies (named after naturalist Thomas Belt), the sweet shoots at the ends of the leaves of tropical acacia species. Spiders also feed on these formations.

The first thing that catches your eye when meeting with is their long, constantly moving mustache (antenna). Spiders do not have antennae. Their eyes are also simpler, but there are many of them - most often eight. The body is covered with an external skeleton (exoskeleton). It consists of a cephalothorax and abdomen, connected by a stalk.

Not only inquisitive schoolchildren, but also many adults are interested in the question: is a spider an insect or not? Indeed, at first glance it may seem that the answer is obvious, and spiders are one of the varieties of insects, but this is not so. They belong to a separate class of arachnids, because they have a lot of differences with insects.

Spiders appeared on our planet a very long time ago, about 400 million years ago. It is believed that they originated from a crab-like ancestor. Insects appeared almost 100 million years later and created a separate class. Today, about 40 thousand species of arachnids live on earth. If we consider in detail the anatomy of these creatures, then questions like "A spider is an insect or not?" should not occur. Everyone knows that insects have six legs, but arachnids have eight, besides they have eight eyes, only some species have six or two. These creatures have no teeth, but there are hook-shaped jaws with special channels designed to penetrate the poison into the body of the victim.

Doubts about whether the spider is an insect or not will disappear immediately if we consider how it eats. If praying mantises eat caught flies, then arachnids cannot do this, because they have extraintestinal digestion. They inject digestive enzymes into the victim, which turn the insect into soup, and the spiders can only suck out the contents of the shell.

Many creatures know how to spin a web, but they will not make it as strong and elastic as the prey trap that a spider prepares. Reproduction also causes these creatures to weave special cocoons to keep their eggs and little spiders laid. If we compare the web with steel, then the first will be five times stronger than the second, and the pencil-thick threads will not be able to break through the plane that crashed into the network.

It is not clear why many think about the question of whether a spider is an insect or not: there are a significant number of differences between these two classes. The body of these creatures is divided not into three, but only into two sections: the abdomen and the cephalothorax. They make a web from a fluid secreted from warts located at the end of the belly. From this material, spiders build houses for themselves, make a flying carpet on which they travel long distances, weave cocoons for eggs, and hunt insects with nets.

These creatures are quite nimble in their webs, while mosquitoes, flies and other unfortunates just stick to it. The fact is that spiders weave sticky and non-sticky threads, the first ones are needed to catch the victim, and they move along the second ones. Even if they accidentally get on the sticky part, they will not get confused, since their body has a fatty coating.

Modern science has already given an exact answer to the question: "Is a spider an insect or not?", highlighting these creatures in a separate class. In central Russia there are no arachnids dangerous to human life, although it is necessary to be careful with them. The spider will never attack first, it only defends itself or bites when frightened. A bite can only be accompanied by burning, severe pain and fever. But there are also dangerous representatives of this species: the most famous are the tarantula and karakurt. Their bite causes general poisoning of the body, which sometimes leads to death.

There is an assumption that spiders appeared in the Paleozoic era, in the Carboniferous period. This was about 2.5 billion years ago.

Among the inhabitants of the fauna, they are classified as invertebrate creatures. Spiders belong to arthropods, which are characterized by the presence of jointed limbs, a hard chitinous cover that acts as an external skeleton.

Spiders are often called "arachnes" - this name comes from the suborder Orthognatha, to which it is assigned. It differs from other varieties of insects in numerous species diversity, specific appearance. There are about 3 tens of thousands of individuals on the entire planet.

The suborder Orthognatha includes spiders, otherwise called mygalomorphs. This species is covered with hairs, small in size. Mygalomorphs are primitive species according to the structure of the jaws - a jaw claw on one of the jaws. Mygalomorphs live in the dungeon. These should include:

• tarantulas belonging to the Theraphosidae family;
• ctenises;
• funnel spiders;
• digger spiders.

The above species live in warm climatic latitudes.

The tarantula has a certain level of intelligence: they cannot distinguish their relatives from others. Some individuals are excellent pets. They have developed the ability to emotionally feel the mood of the owner, to catch mood swings, at the same time they love to play, they can protect the owner if he is in danger, they can dance to music.

Insects and arachnids are divided into two separate classes that belong to the type of animals - arthropods. They have certain differences in structure, and there are a significant number of them. Legs are one of the first differences. If an insect has 6 of them, then a spider has 8. In addition, it has chelicerae - small limbs with poisonous claws, they are located next to the mouth of an arthropod.

Front part of the body: insects have a movable head, which cannot be said about arachnids. They do not have a clear division into a head, no neck. As a rule, the head is combined with the neck, called the cephalothorax.

Eyes. In insects, there are two of them, the structure of the organs of vision is the most complex. Arachnids have 8 eyes, some species have 6, representatives with 2 eyes are rare.

Thus, the spider is not an insect. It will be a mistake if it is confused with a representative of insects. In order to prove that an individual is an animal, it is enough to count the number of legs, arachnids have singular eyes with lenses, they lack antennas inherent in insects.

According to scientists, the spider is the oldest animal. Scientists have discovered a web located in a piece of amber stone, which today is 100 million years old.

Krinitsyn Oleg

When I was little, I was very afraid of spiders - I ran away and hid from them. And when I grew up, I decided to learn more about them so as not to be afraid, and maybe even make friends with these mysterious creatures.

In the summer I visited my grandmother in the village, I had the opportunity to follow the spiders. I even overcame my fear and began to pick them up and see how they behave. It was very interesting. Adults knew a little about the life of spiders, so I began to look for material in books. I was able to learn a lot of interesting things about these amazing animals from encyclopedias. I was very interested to know: how many species of spiders exist; what species are the spiders I observed; how they differ from each other; what do they eat; how they move on walls and ceilings. Also, I wanted to find the answer to the question: “Where do they get the web from?” And I also wanted to figure out why the spider is not an insect, because they are so similar. Many consider them nasty, dangerous, disgusting. Therefore, I would like to change my mind about spiders, to tell adults, classmates, why spiders are interesting and useful.

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Department of Education

Administration of the municipality

Nadymsky district

Municipal educational institution

"Average comprehensive school № 6
with in-depth study of individual subjects ", Nadym

Research work

Krinitsyn Oleg,

2nd grade student.

Pedagogical leader:

Katyukova Olga Viktorovna,

primary school teacher.

Nadym

2013

I.Introduction

Of the creatures that live near us, spiders are without a doubt the most interesting ... Karl Frisch

When I was little, I was very afraid of spiders - I ran away and hid from them. And when I grew up, I decided to learn more about them so as not to be afraid, and maybe even make friends with these mysterious creatures.

In the summer I visited my grandmother in the village, I had the opportunity to follow the spiders. I even overcame my fear and began to pick them up and see how they behave. It was very interesting. Adults knew a little about the life of spiders, so I began to look for material in books. I was able to learn a lot of interesting things about these amazing animals from encyclopedias. I was very interested to know: how many species of spiders exist; what species are the spiders I observed; how they differ from each other; what do they eat; how they move on walls and ceilings. Also, I wanted to find the answer to the question: “Where do they get the web from?” And I also wanted to figure out why the spider is not an insect, because they are so similar. Many consider them nasty, dangerous, disgusting. Therefore, I would like to change my mind about spiders, to tell adults, classmates, why spiders are interesting and useful.

Purpose of the study:explore external structure spiders, find differences between spiders and insects, make sure spiders are not insects.

Tasks:

• to study the literature on the topic of research work;
• compare spiders and insects;
• find out what kind of spiders live at my grandmother's house and in the garden;
• observe their lives
• present the work to the children.

Hypothesis: spiders do not have signs of insects, they are not insects

I have determined the ways and methods of research:

• study of sources of information;
• observation;
• conversation;
• analysis;
• practical work.

Object of study: spiders.

Subject of study: spider life.

II.Main part

2.1. Who are spiders?

From the encyclopedia, I learned that spiders are the largest order of arachnids. Spiders (lat. Aranei ). 35,000 species have been described, and this number should rise to about 50,000, since all spiders have not yet been studied.

Spiders on Earth appeared so long ago that it’s even hard to imagine (approximately three hundred and fifty million years ago), the ancestors of spiders first climbed onto land from the water in which the entire animal world lived in those distant times.

Spiders appeared a hundred million years before flying insects, and when people appeared, spiders already felt like masters and looked like they do today.

Spiders are currently one of the thriving animal groups. It is difficult to find a place in nature where spiders would not live. They mastered everything natural areas Lands from deserts and rainforest to the islands of Antarctica. The conquerors of Everest found a spider at an altitude of 7,000 meters. Spiders survive where other animals die, such as in the highlands and in caves. Spiders are very hardy and interesting animals.

All spiders are predators, but since they do not have good eyesight, they lie in wait for their prey. Spiders catch their prey on the web or by other means. Spiders that catch their prey with their webs are called web spiders. With the help of the chylecera, the spider injects poison into the victim. After several hours, the prey turns into a thick mass and the spider “drinks” it. Yes, yes, it is “drinking”. Spiders eat only liquid food. They suck out the victim, leaving a dry shell from it. Even such giants as the bird spider "drink" their victims, as if through a straw. Moreover, their menu includes not only insects, but even lizards and birds. Sometimes they eat each other.

However, there are spiders that do not use webs for hunting. They catch up with prey by jumping, waiting in ambush, etc. The victim of a hunter can be: frogs, small rodents, insects ...

Spiders, scorpions and ticks are similar to each other, so they are classified as arachnids. Spiders are close to insects in a number of ways, but they clearly differ from them, and these groups are connected only by a very distant relationship.

2.2 Why a spider is not an insect

In order to figure out whether a spider is an insect or not, I decided to study and compare the structure of a spider with the structure of insects.

I learned that spiders have 2 body parts: cephalothorax and abdomen. Spiders have 4 pairs of legs and pedipalps are very similar to legs. The bases of the pedipalps are transformed into chewing organs.

Spiders have up to 8 simple eyes. Despite such a large number of organs of vision, many arachnids see very poorly. So bad that this distance is on average 30 cm.

Spiders do not have a skeleton inside the body. They have a hard outer shell called an "exoskeleton". As the spider grows, it is necessary to shed the old tight shell. When molting, the spider climbs out of the old body and waits for its new delicate skin to dry and harden. At the moment of molting, spiders are especially vulnerable.

At the end of the abdomen are arachnoid warts. The substance coming out of them hardens and turns into threads of extraordinary strength.

Insects, Insecta - a class of creatures with no vertebrae and jointed legs. They differ in body structure (divided into 3 sections - head, breast and abdomen), one pair of antennae, 3 pairs of legs on the chest and mainly 2 pairs of wings. Some insects secrete various substances through special organs: cobwebs, silk, wax, poisons. The skin of insects is formed mainly from chitin, which forms a strong outer skeleton. The cavities are filled with the so-called fat body.

Insects have two eyes. They feed on plant and animal products. Insects in a colossal number of species inhabit the earth. Appeared in the distant geological periods(starting with coal). About 10,000 species are known in the fossil state.

Thus, we can conclude: spiders are not insects. They belong to the class of arachnids, and differ from insects primarily in the structure of the body. The body of the spider consists of the cephalothorax and abdomen, breathing is carried out by lung sacs and tracheae. In insects, the body is divided into the head, chest and abdomen, and they breathe exclusively through the trachea. In addition, the spider has 4 pairs of legs, in turn, insects are arthropods that have 3 pairs of legs and 2 pairs of wings . Also, an insect can be distinguished from a spider by the presence of antennae, while spiders do not have antennae.

comparison table

"What is the difference between spiders and insects"

2.3 Interesting facts about spiders

It should be noted that spiders, especially tarantulas, have a certain amount of intelligence, they can even distinguish between their own and others. It is these spiders that are often used as pets. They are also very subtle and feel the mood of their own master, and therefore you can even play with them, they are even able to protect their own master if he is in danger, and they can also dance to the music.

Spiders of the species Cyclosa mulmeinensis from Singapore are able to make a copy of themselves from the garbage and remains of victims that have fallen into the network. The model has "legs" and reflects light like its prototype, and a breath of wind can give the impression that it is moving. Thus, these spiders deceive the wasps that hunt them, since the dummy is located in the most prominent place of the web, and in most cases predators attack it, allowing the real spider to hide.

Spiders of the genus Cyclocosmia, living in Asia and North America, have an original appearance: their abdomen ends with a hard surface in the form of a disk, on which numerous grooves form an intricate pattern. In the species Cyclocosmia truncata, for example, this pattern resembles a seal. When this spider is threatened, it crawls into its hole and plugs the entrance with its disk, which coincides with inlet by diameter.

Spiders of the species Theridion grallator, found only on Hawaiian Islands, have an amazing body coloration, reminiscent of a smiling human face, and the coloring of each individual is unique. Presumably, such a drawing should scare them away. the only enemies, birds.

It is possible to sew clothes from cobwebs, only it is several orders of magnitude more difficult and more expensive than from ordinary silk obtained from silkworm. The first documented mention of such clothes dates back to 1710, when the French scientist and businessman de Seux Hiler made gloves and socks from "spider silk" and presented them to King Louis XIV. And most recently at the American Museum natural history exhibited a piece of fabric measuring a little more than 3 square meters. To obtain it, several dozen workers caught golden spiders in Madagascar for 4 years, then carefully removed the threads from them and released them back into nature.

The web has a huge strength potential. A pencil-thin thread made from their web could stop a Boeing at full speed. AT this moment ultralight and durable bulletproof vests using webs are being developed.

2.4 Spiders that I watched in the summer in the village

At my grandmother's in the village, I watched the haymaker and funnel spiders.

2.4.1 Spider - Harvester

Haymaker - we all know this amazing creature from the arachnid family on very long legs. If you grab a haymaker by the leg, it will easily come off and will twitch convulsively for many minutes. It is because of this movement, similar to the movement of a scythe, that the well-known names "spider-mow-hay" or "haymaker" arose.

The leg of the harvestman comes off with such ease that one gets the impression that it is very loosely attached to the body. Actually it is not. The kicking off of the leg is voluntary and depends on a specific muscular movement. This phenomenon is called autotomy - self-mutilation. The autotomy of the legs in the haymaker, like the autotomy of the tail in lizards, serves to save oneself from enemies. Approaching its prey, the predator first of all stumbles upon the palisade of limbs, and the torn off and twitching leg distracts it from the haymaker fleeing on the remaining legs. Therefore, it is often possible to meet harvestmen with an “incomplete” set of legs.

We will never see a haymaker weaving a web, arranging a lair for himself, or descending on a thin web thread - these arthropods do not have spider warts.

You can meet harvestmen on a tree trunk or on a fence, on a house wall or in cracks in the bark, under stones and in bedding in a forest, garden, park, field, or vegetable garden. Deciduous and mixed forests. In mountainous areas, these animals are found on rocks, in placers of stones and caves.

Haymakers go hunting at dusk or at night. They feed on insects, small spiders and other invertebrates.The biggest threat to spiders is the spiders themselves. In the event of a hunger strike, they even kill their own offspring.

In the village of my grandmother, I managed to observe such a story. I planted two harvestmen in a plastic cup and fed them flies. But for a while I forgot about them and did not feed them, and two days later I discovered that there was one living spider in the glass - which is larger, and the other was eaten.

2.4 Funnel spiders

Perhaps one of the most famous spiders in Russia. He really likes to settle in houses and households. buildings. Usually weaves its net somewhere in the corner on the ceiling or behind the closet. In general, where the hostess's broom does not reach him. If it reaches it, the spider will not be upset: by the next morning, it will mockingly build a new web in another corner. In the middle of the web of a house spider there is always a funnel that leads to a small hole - his home. Here he sits and waits for prey - flying insects. As soon as someone touches the web, the owner jumps out of his hiding place and instantly cracks down on the troublemaker. There is usually a lot of dust in a person’s home, so the web becomes dirty very soon. It is his web that sticks to the ceiling and constantly sways.

The male grows up to 10 mm (excluding the length of the legs), the color is yellow-gray with brown spots. The female is larger, the color is the same as the male. Sometimes, if there is a lot of food, they grow to an impressive size and at times crawl along the walls, frightening children and women.

The spider is shy and never attacks people. However, he can still bite if you accidentally crush him. However, the poison is not at all dangerous to humans, it does not cause any visible consequences. The house spider is useful, as it exterminates various insects harmful to people right in the apartment: flies, mosquitoes and various moths.

And I also learned a lot interesting fact: if you play musical instruments at home, then the spider will come out to listen to you from the mink, or even start to "dance" on its web. It turns out that the point here is not at all the musical preferences of spiders. Music vibrates the web like small insects, and the spider, in anticipation of dinner, comes out to visit: "who is shaking my web there?". Not finding anyone, he is probably very surprised and looks on for a while, puzzled. And then he even tries to "shake off" an invisible insect from the web.

Funnel spiders, by the way, are very sensitive to changes in temperature and humidity. Therefore, they can serve as a kind of living barometers. Previously, house spiders were completely trusted in such matters.

III. Conclusion

Some people are disgusted by or afraid of spiders. Often this is due to the fact that we know very little about these octopuses. However, only a small number of spider species are dangerous to humans, and they do not live in Europe. Spiders are not insects, as many people think, they feed on them. Many spiders weave webs that catch their prey. And this makes spiders useful to humans: they free us from flies, mosquitoes and other insects that often bother us. Without spiders, we would, if I may say so, "get bogged down" in insects.

Exploring the life of spiders, I learned a lot of interesting things, read various literature about the life of animals and came to the following conclusion:

Spiders are not insects.

The life of spiders is very interesting.

Live next to us different types spiders.

The spider obtains its livelihood with the help of the web.

Spiders - predict the weather, they are experts in weather changes.

The spider is man's best friend!

In the future, I intend to study the life of these interesting animals even more deeply. And I will definitely share my knowledge and observations with my classmates, telling them about the amazing and diverse world of spiders and their benefits to humans.

Bibliography

1. "Puzzles wildlife»; Moscow "ROSMEN", 2004
2. "My first book about animals"; Moscow "ROSMEN", 2006
3. "Around the world"; A. Tikhonov, Moscow "Bustard plus" 2008 https://accounts.google.com
   

   Slides captions:

   Why is a spider not an insect? Of the creatures that live next to us, spiders are without a doubt the most interesting ... (Karl Frisch) Prepared by Oleg Krinitsyn

   Foreword When I was little, I was very afraid of spiders - I ran and hid from them. And when I grew up, I decided to learn more about them so as not to be afraid, and maybe even make friends with these mysterious creatures. In the summer I visited my grandmother in the village, I had the opportunity to follow the spiders. I even overcame my fear and began to pick them up and see how they behave.

   Who are spiders? Spiders appeared on Earth a very long time ago, about three hundred and fifty million years ago, earlier than flying insects, and when people appeared, spiders already felt like masters and looked the same as they do today. It is difficult to find a place in nature where spiders would not live. Spiders survive where other animals die, such as in the highlands and in caves.

   Who are spiders? All spiders are predators, but since they do not have good eyesight, they lie in wait for their prey. Spiders catch prey on the web. They inject poison into their prey. After several hours, the prey turns into a thick mass and the spider “drinks” it. Yes, yes, it is “drinking”. Spiders eat only liquid food.

   Why a spider is not an insect Spiders are close to insects in a number of ways. In order to figure out whether a spider is an insect or not, I decided to study and compare the structure of a spider with the structure of insects. The body of the spider consists of the cephalothorax and abdomen, breathing is carried out by lung sacs and tracheae. In insects, the body is divided into the head, chest and abdomen, and they breathe exclusively through the trachea.

   Why a spider is not an insect In addition, the spider has 4 pairs of legs, in turn, insects are arthropods that have 3 pairs of legs and 2 pairs of wings. Spiders have up to 8 simple eyes. But despite this, they see very poorly. This distance is on average 30 cm. Insects have two eyes. Also, an insect can be distinguished from a spider by the presence of antennae, while spiders do not have antennae. Thus, we can conclude: spiders are not insects.

   Interesting facts about spiders Interestingly, spiders, especially tarantulas, have a certain amount of intelligence, they can even distinguish between their own and others. It is these spiders that are often used as pets. They also feel the mood of their master very subtly, and therefore you can even play with them, they are even able to protect their master if he is in danger.

   Interesting Spider Facts Spiders of the species Cyclosa mulmeinensis from Singapore are able to make a copy of themselves from garbage caught in the net. Thus, these spiders deceive the wasps that hunt them.

   Interesting facts about spiders Spiders that live only on the Hawaiian Islands have an amazing body color that resembles a smiling human face, and the color of each individual is unique. Presumably, such a pattern should scare away their only enemies, birds.

   Watching Spiders At my grandmother's village, I watched the haymaker and funnel spiders.

   Harvester You can meet harvestmen on a tree trunk or on a fence, on the wall of a house or in cracks in the bark, under stones. Harvester never weaves a web - they do not have spider warts. If you grab a haymaker by his long leg, it will easily come off and will convulsively twitch for many minutes. It is because of this movement, similar to the movement of a spit, that the name “haymaker” arose.

   Harvestman Harvestmen go hunting at dusk or at night. They feed on insects and small spiders. But sometimes they eat each other. In my grandmother's village, I put two haymakers in a plastic cup and fed them flies. Then I forgot about them and didn't feed them, and two days later I discovered that there was one live spider in the glass - which is bigger, and the other was eaten.

   Funnel spider The funnel spider is one of the most famous spiders in Russia. Likes to stay in houses. Usually weaves its net somewhere in the corner on the ceiling or behind the closet. In the middle of the web there is always a funnel that leads to a small hole - his home. If someone touches the web, the spider jumps out of its hiding place and instantly grabs the troublemaker.

   Video Feeding the funnel spider

   Conclusion The spider is shy and never attacks people. However, he can still bite if you accidentally crush him. However, the poison is not at all dangerous to humans, it does not cause any visible consequences. The house spider is useful, as it exterminates various insects harmful to people right in the apartment: flies, mosquitoes and various moths. Some people are disgusted by or afraid of spiders. Often this is due to the fact that we know very little about these octopuses. Exploring the life of spiders, I learned a lot of interesting things, and came to the main conclusion: The spider is a friend of man!

studying wildlife- the structure, origin and genetics of organisms, scientists make up a huge scheme. They organize their data. Scientists have introduced a number of taxa. The most basic of them are kingdom, class, order, family, genus and species. The science of systematics does a great job. Often you have to make changes to the system, as scientists discover something new.

Spider - an insect or not, and why?

Looking at the system of the world of wildlife, we can see that historically there were 5 kingdoms: animals, plants, fungi, bacteria and viruses. Spiders belong to the animal kingdom. An interesting question is: is a spider an insect or an animal that does not belong to the same class?

Common signs of insects and spiders

Insects and spiders belong to the same phylum of arthropods. Arthropods have the following external signs:

1. The body is divided into sections.
2. The limbs are jointed, they are the main organs of movement. They are movably connected to each other. Animals are capable of a variety of movements.
3. The chitinous cover protects the body of the arthropod, it also covers the limbs. Protects against mechanical damage, does not let water through (prevents evaporation in terrestrial arthropods, prevents water from entering the body - in aquatic organisms), and also serves as an external skeleton (muscles are attached to it).
4. The presence of a molt. Due to the fact that the chitinous cover does not stretch.

What class do spiders belong to?

The answer to the question: "Is a spider an insect?" systematics gives. What class do spiders belong to? Spider - insect or not?

Despite the presence of common features, spiders and insects used to belong to different classes: arachnids (Arachnida) and insects (Insecta). AT modern taxonomy Two classes of insects were distinguished: cryptomaxillary and open-maxillary, combined into one superclass - six-legged (Hexapoda). The arachnid class stands apart. Is a spider an insect? The answer is no. However, how is it different from insects?

Signs of insects

The body of an insect is divided into head, thorax and abdomen. The head consists of five fused segments. On the head there are antennas with receptors for touch and smell. The eyes are compound, that is, they consist of many simple eyes. There are mouthparts for chewing food.

The chest includes segments: anterior, middle and posterior. Each segment carries a pair of motor limbs. In addition, the middle and rear ones include a pair of wings each: chitinized elytra and, in fact, wings. The abdomen also consists of segments, on the sides of which paired respiratory openings open.

Signs of arachnids

Signs that are unique to arachnids show how different spiders are from insects. They give an answer to the question: is a spider an insect or not.

The body of a spider is divided into the cephalothorax and abdomen. That is, there is no jumper between the head and chest, they are merged in the course of evolution. And in such an arachnid as a haymaker, even the cephalothorax is merged with the abdomen. Haymakers often settle in human homes. They have long legs, but they should be distinguished from the long-legged spider, whose cephalothorax and abdomen are separate.

The absence of antennae distinguishes spiders from insects. But there are chelicerae - limbs bearing claws. They serve to inject poison into the victim. The chelicerae of males are noticeably longer than those of females. Pedipalps are a sign of spiders. They look like a fifth pair of legs. However, spiders do not rely on it, they use it to capture prey.

Spider eyes are not faceted. They have one to six pairs of eyes. Most often 8. However, vision is very poor. Distinguish objects at distances up to 30 centimeters.

Spiders do not chew their prey. They have a narrow mouth opening with which they suck in the already digested liquid. To do this, they first inject digestive juice into the victim, in addition to poison. They wait for some time until the food is digested. They suck up the finished liquid and can again add digestive enzymes to it. This type of digestion is called extraintestinal.

The cephalothorax consists of six fused segments, each bearing a pair of limbs: chelicerae, pedipalps, and walking limbs. Spiders have eight legs and no wings.

The spider glands are located in the lower part of the abdomen. Only spiders weave the web needed for hunting. The vast majority of spiders are predators.

The respiratory organs are not only the trachea, but also leaf-shaped lungs. The latter are depressions in the abdomen. Their walls form many thin plates. Through them, diffusion of gases into the hemolymph occurs. The lungs open outward through the respiratory openings.

Convergent features of spiders and insects

Scientists also once decided whether a spider is an insect or not. They were faced with the task of finding out the origin of some of the organs found in both spiders and insects.

Malpighian vessels are excretory organs that characterize both spiders and insects. However, it is believed that in the course of evolution these organs developed independently of each other, that this is a convergent similarity. Malpighian vessels are numerous tubules. They blindly end in the body cavity of the arthropod, and exit through the opening into the intestine. Waste substances are filtered into the tubes from the hemolymph and excreted into the environment.

The presence of a tracheal respiratory system in spiders and insects is also considered convergence. Thus, the decision of convergent similarity only reinforced the inclusion of spiders and insects in different classes.

Schoolchildren and biology lovers are wondering: "Is the spider an insect or not?". Indeed, their small size, some similarity in structure makes them look like them. However, the differences are enough to place spiders in a different class.