Why are insects needed on earth? The role of insects in nature and their practical significance

The role of insects is extremely large both in human life and in natural processes. Due to the fact that insects make up a significant proportion of terrestrial fauna, they greatly influence plant and animal world Earth. Insects are found in all land areas, including deserts, high mountains and polar regions.

The existence of many insects is closely related to the life of plants, as they consume living plants: roots, stems, leaves, fruits, seeds. During mass reproduction, insects destroy or damage plants over vast areas.

The role of insects in nature and human life is enormous

However, in addition to harm, insects bring great benefits to crop production as pollinators of flowering plants. In the course of evolution, remarkable mutual fitness has developed between many species of insects and flowering plants (for example, plants have various devices for pollination by certain types of insects, and in insects the length and shape of the proboscis strictly correspond to the structure of the flowers of the plants that they pollinate).

Insects are destroyers of dead plant parts. Many types of insects and their larvae, living in the ground, digging tunnels and loosening the soil, accelerate the formation of humus. Many vertebrates (fish, amphibians, reptiles, birds and mammals) feed on insects at various stages of development.

In connection with human economic activities, it is important to preserve the species diversity of insects. The use of insecticides to control pests of agricultural and tree crops, plowing of land, due to which the number of some species is sharply reduced wild plants, the existence of some insect species is under threat.

To protect endangered insects, special reserves are being created in our country, and many (about 20 species) are already listed in the Red Book. These include two species of praying mantises - predatory insects that feed on other insects, a mollusc-eating ground beetle, an alpine longhorned beetle, a gigantic hawkmoth and several species of butterflies: the polyxena swallowtail, Apollo, the death's head hawkmoth, the Proserpina hawkmoth, the oak hawkmoth, Saturnia aglia, Saturnia minor, etc.

Biological method of pest control

To combat harmful insects, along with mechanical, chemical and agrotechnical methods, biological control methods are increasingly being used, i.e. destruction of insects at all stages of development with the help of their natural enemies. Such enemies of insects are frogs, toads, lizards, wild birds, shrews, hedgehogs, moles, the bats etc. Therefore, all these animals must be protected and, if possible, attracted to fields, vegetable gardens, and orchards. Poultry for last years They are also increasingly used to kill pests.

Pests and insects have many natural enemies. Great importance in the destruction of pests belongs to riders and other insects. Ladybugs, for example, destroy aphids and other pests. Predatory beetles (ground beetles) hunt gypsy moth caterpillars.

Previously, a lot of planned work was carried out on breeding and using various types insects to control plant pests.

In special laboratories, certain species of ladybugs, ichneumon fly, Trichogramma and other insects are bred in large numbers. They are released in areas where there is a massive outbreak of pests. Biological methods of controlling plant pests have a great future.

The role and importance of insects in nature are enormous. The number of insect species far exceeds the number of species of any other group of animals; according to rough estimates, at least 108 billion insects simultaneously live on our planet.

The positive activity of insects in nature is expressed in their pollination of plants, for example, about 30% of European flowering plants are pollinated by insects. Some plants are not able to reproduce without special pollinators. Clover yielding in New Zealand excellent harvests, did not produce seeds until bumblebees, which were absent there, were introduced as clover pollinators. The main role among pollinators is played by Hymenoptera and especially bees and bumblebees; the second most important are dipterans and the third are butterflies.

Insects are of great importance in soil-forming processes, especially termites and ants. These insects, like the larvae of many insects living in the ground, loosen the soil with their passages, promote ventilation and moisture, and enrich it with humus. Without the activity of insects, for example, the decomposition of litter is impossible coniferous plants, and where this does not occur, peat-like infertile layers accumulate. The destruction of animal corpses and excrement by insects is of great sanitary importance.

The role of insects in cycle of substances in nature. Almost every class of vertebrate animals (especially birds and mammals) has entomophages - forms that feed exclusively on insects.

The negative consequences of insect activity are no less significant. Thus, many of them feed on living plant tissues, causing significant harm. Damage caused by insects is varied and affects various plant organs: root system, stems, trunks, leaves, flowers, fruits, etc. In some cases, this may be the destruction of plant tissue - gnawing, boring holes (passages gnawed in leaves are called mines). In other cases, the presence of insects leads to the formation of galls, which are growths of parts of the plant. Both of these lead to a weakening of the plant organism, a decrease in its resistance to fungal and other diseases, a decrease in the production of fruits and seeds, and often to death.

Failure to comply with precautionary measures leads to the introduction of insect pests into areas of the globe where they were previously absent. Not finding natural enemies in the new conditions, pests begin to multiply quickly. The absence of protective reactions developed over a long period of time in the plants on which the pest settles leads to the fact that the damage caused increases significantly.

The harmful properties of insects can sometimes be used by humans to their advantage. Successful experience The use of insects to limit the spread of certain plants (in Australia, for example, specially acclimatized leaf beetles destroyed St. John's wort, which was growing rapidly on agricultural land) allows us to hope for the development of biological methods for controlling weeds.

Sometimes the transfer is accomplished by simple contact with transmitting insects, for example, when they contaminate food, etc. In this way, various diseases are spread by the house fly (Musca domestica), capturing bacteria, helminth eggs and transmitting them to humans. Flies carry about 70 species of different organisms, many of which are causative agents of dangerous diseases (cholera, diphtheria, etc.).

    Insects pollinate the plant - this is the most important part of their many purposes.

    They can also be noted nutritional value for other inhabitants of the planet, because insects are the main food for birds.

    Imagine a world without plants and without birds. I think there is no need to continue. The answer is pollination and food.

    The importance of insects is very great, because they are all part of the general ecosystem of our planet and this is not just like that. Without them, it’s even difficult to imagine what our planet would be like. Some plants cannot live without insects carrying pollen. Accordingly, if you eliminate these insects from nature, these plants will die.

    And these plants themselves are needed by herbivorous animals, which, if there is an insufficient number of plants, will not be able to eat normally and will die out, which will lead to the fact that there will be fewer herbivorous animals, and then carnivorous animals will also die out. The absence of carnivores will also affect the lives of many people (non-vegetarians): there will be no meat, animal skins, etc., and the business of many enterprises will collapse. I have given the functions of insects in more detail here.

    Insects are an important link in the animal food chain. If we fantasize and imagine that they will suddenly disappear, then the natural balance will be disrupted and hard-to-predict consequences will begin. For example, if midges and mosquitoes disappear in a swamp, then the frogs that feed on them will also disappear, and accordingly, some inhabitants of the swamp, such as birds or snakes, will have nothing to eat. They will go to other areas and may also disappear. The fate of the swamp itself also becomes uncertain. And so on according to cause and effect.

    Some insects benefit humans and nature, such as bees and ants. Not to mention the lack of honey, it is easy to imagine that the plants will not be pollinated, accordingly some vegetation will disappear, hence the load on the soil (such as its desertification), etc. Ants are the orderlies of the forest. Again, the load on the biosystem.

    Of course, such disappearances are fantastic and one can imagine that nature will somehow make up for such losses, but it will no longer be the same, and there are no guarantees at all that it will wither rather than flourish.

    So the role of insects in the balance of nature and for humans is quite large.

    In nature, they are a segment of a single ecosystem, pollinate plants, have a beneficial effect on the soil, become a link in the food chain, etc., but in human life their role is mostly negative: annoying mosquitoes and flies, unpleasant cockroaches, not to mention pubic lice and at the same time, this is a good signal about the unsanitary condition of the premises, hygiene and lifestyle.

    Insects play very important role in the life of our entire system. They create ecological balance. Various mammals, frogs and lizards, as well as fish feed on insects. Frogs, for example, eat 95 percent insects in their diet.

    The role of insects in nature:

    • help in plant reproduction (as they carry pollen - bees, bumblebees and others);
    • are the main food for most invertebrates and vertebrates;
    • decompose plant and animal residues, resulting in the formation of humus (good for the soil);

    The role of insects in human life:

    • used in the human diet (and larvae from them too);
    • with the help of some types of insects honey, wax, propolis and other useful products are obtained;
    • used to control weeds in agriculture.

  • Insects in nature great amount and it’s a gift that they are small. Due to their abundance, insects play an important role both in nature and in human life. First of all, they themselves serve as food for various animals and birds, and perhaps they will play the role of one of the main sources of nutrition for humans. Insects process organic remains, they fertilize the soil and loosen the soil, that is, they contribute to the yield of fields. In addition, insects are plant pollinators, and without them, many plants simply would not be able to bear fruit. There are even domesticated insects, such as bees and silkworms, from which humans obtain either honey and related products or silk. And the insects are simply beautiful.

    Insects play both negative and positive roles in human life. The positive side includes: production of honey, wax, silk; the use of some insects as a method of combating others; plant pollination; In Asia and Africa they also eat insects with great appetite; In addition to all this, they also play a global role, taking part in maintaining ecological balance.

IMPORTANCE OF INSECTS

The importance of insects in nature

Insects make up about 80% of all animals on Earth; according to various estimates, there are from 2 to 10 million species of insects in the modern fauna, of which just over 1 million are known so far. Actively participating in the cycle of substances, insects play a global planetary role in nature.

More than 80% of plants are pollinated by insects, and it is safe to say that a flower is the result of the joint evolution of plants and insects. The adaptations of flowering plants to attract insects are varied: pollen, nectar, essential oils, aroma, shape and color of the flower. Adaptations of insects: sucking proboscis of butterflies, gnawing-licking proboscis of bees; special pollen-collecting apparatus - bees and bumblebees have a brush and a basket on the hind legs, megachila bees have an abdominal brush, numerous hairs on the legs and body.

Insects play a huge role in soil formation. Such participation is associated not only with loosening the soil and enriching it with humus by soil insects and their larvae, but also with the decomposition of plant and animal residues - plant litter, corpses and animal excrement, while simultaneously fulfilling a sanitary role and the circulation of substances in nature.

They perform a sanitary role the following types insects:

· coprophagous - dung beetles, dung flies, cow flies;

· necrophages - carrion beetles, gravediggers, leather beetles, meat-eating flies, carrion flies;

· insects - destroyers of dead plant debris: wood, branches, leaves, pine needles - borer beetles, longhorned beetle larvae, golden beetles, horntails, long-legged mosquitoes, carpenter ants, fungus gnats, etc.;

· insects - orderlies of reservoirs feed on suspended or decaying matter that settles to the bottom organic substances(detritus) - larvae of mosquitoes, or bells, mayflies, caddis flies, purify water and serve as a bioindicator of its sanitary condition.

The importance of insects in human life

In life and economic activity people have both positive and negative meanings.

Of the more than 1 million insect species, only about 1% are actual pests that need to be controlled. The bulk of insects are indifferent to humans or beneficial. Domesticated insects are the honey bee and the silkworm; beekeeping and sericulture are based on their breeding. The honey bee produces honey, wax, propolis (bee glue), apilak (bee venom), royal jelly; silkworm - a silk thread secreted by the spinning glands of a caterpillar during the construction of a cocoon; the silk thread is continuous, up to 1000 m in length. In addition to these insects, valuable products are produced by: caterpillars of the oak cocoon moth, their coarser silk thread is used to make tussock fabric; lac bugs secrete shellac, a wax-like substance with insulating properties used in radio and electrical engineering; carmine bugs (Mexican and Ararat cochineal) produce red carmine dye; Blister beetles secrete a caustic substance called cantharidin, which is used to make blister plaster.

Pollinating insects, representatives of many orders, among which Hymenoptera occupy an important place, increase the yield of seeds, berries, fruits, and many flowers cultivated plants- fruit and berry, vegetable, fodder, flower.

The Drosophila fruit fly, due to its fertility and reproduction rate, is not only a classic object of genetics research, but also one of the ideal experimental animals for biological research in space. Fossil insects are used in stratigraphy to determine the age of sedimentary rocks.

Beneficial insects

Seven-spotted ladybug (Coccinella septempunc-tata L.). A small black beetle, 6-8 mm long, with red elytra, on which 7 black round spots clearly appear, which is how the insect got its name. The beetles fly well and with amazing accuracy find colonies of aphids, which they greedily eat. Here, on leaves or branches, females lay piles of yellow shiny eggs. Small, black, six-legged larvae emerge from them and immediately begin to eat aphids, just like the adults. Where the cows have settled, the aphids are completely destroyed. This picture can often be observed in gardens, berry fields and fruit nurseries. Beetles overwinter in crevices of buildings, under fallen leaves, in dead grass and other places. Early in the spring, after overwintering, they emerge from their shelters, crawl out onto trees and begin to eat pests. In favorable years, cows (they are also called ladybugs) multiply quickly and eat not only aphids, but also other small pests. In search of food and water, they accumulate en masse near bodies of water, on the sea coast, on rocks, crawl along roads where a large number of they die under the feet of passers-by. At such a time, ladybugs should be saved from death, collected in special boxes made of thick mesh and stored in refrigerators or basements in cold places so that in the spring they can be released onto plants damaged by aphids.

Dragonfly(Leptetrum quadrimaculatum L.). A predatory insect, with large compound eyes occupying most surface of the head, strong gnawing oral apparatus and two pairs of transparent long narrow wings with a dense network of veins. The wings of a dragonfly are always located perpendicular to the body. They fly very quickly, catching many on the fly. small insects, especially mosquitoes, midges, moths and other pests, which bring great benefits to humans. The larvae live in ponds and rivers and feed on small aquatic animals. There are about 200 species of dragonflies in the USSR.

Insects cause enormous economic damage to humanity by eating crops, wooden buildings and other items made from materials of plant origin. These insects include many types of butterflies: apple and plum moths, apple and cotton moths, representatives of the moth family (destroy grain crops, cotton, corn, sunflowers, beets, etc.), pine moth and Siberian silkworm (pests of coniferous forests). Great damage to forests is caused bark beetles, woodcutters and goldsmiths. Leaf beetles, weevils, weevils and chafers cause damage to the green parts of plants. The cockchafer is especially dangerous at the larval stage, which lasts 4–5 years. Larvae feed on roots herbaceous plants and trees. Devastating locust attacks have been a terrible disaster since the dawn of human civilization and affect the economies of many modern states. Termites cause great damage because, thanks to the fauna of intestinal symbionts, they perfectly absorb fiber, destroying huge amounts of wood.

Abundance of insects. Insects are the most numerous class of animals; more than a million species are known. Calculations made by scientists have shown that about 1017 (100,000,000,000,000,000) insect specimens live on Earth at the same time. Due to their abundance, insects play a very important role in nature and in human life.

The importance of insects in nature. Insects live on land and in fresh water bodies wherever life is possible. They even live high in the mountains, in deserts and in polar regions. Insects are not found only in the seas. Due to the wide distribution of insects, their importance in nature is also varied.

The life of many insects is closely related to the life of plants. Huge army These arthropods feed on leaves, roots, stems and other organs and parts of plants, fruits and seeds. Herbivorous insects, when multiplying en masse, damage or destroy plants over large areas. However, the positive significance of insects in plant life is very great. Thus, ants contribute to soil formation. Bumblebees, bees, flies, and some species of butterflies and beetles play an important role in the cross-pollination of flowering plants.

Insects are of great importance in the cycle of substances in nature. Fattening on plant foods, they themselves find themselves prey to other animals (for example, insectivorous birds). Insects such as burying beetles and dung beetles are of very great sanitary importance.

Due to the large number of insects and their high activity, life on Earth would be impossible without these animals.

Harmful insects include those that damage crops, forests and garden trees and other valuable plants are eaten and spoiled food products, technical raw materials (wood, leather, etc.), woolen clothing (the larvae of moth butterflies feed on wool). Insects are known to damage furniture and destroy wooden buildings.

A person has to take into account the importance of insects, protect and breed useful ones, and fight harmful ones.