What is the role of insects in nature, practical and aesthetic value, you will learn from this article.

The value of insects in human life and nature

Thus, insects are of great importance as consumers of animal and plant residues.

Insects are plant pollinators therefore play a role in their reproduction. They also take part in soil formation. These organisms not only loosen the soil, but also enrich it with humus. Insects simultaneously perform the role of orderlies and are participants in the cycle of substances in nature.

Besides, they considered essential element food pyramids : many animals feed on them (amphibians, fish, reptiles, mammals, invertebrates and birds).

The value of insects in human life

Man domesticated insects for his own benefit. The honey bee produces wax, honey, propolis, royal jelly and apilac. On the basis of these "gifts" people developed beekeeping. The domesticated silkworm provides us with silk thread. Also, valuable products are given by lacquer insects (their wax-like substance is used in electrical and radio engineering), caterpillars of the oak cocoonworm (it is used to make scarf fabric from its silk thread), carmine insects (they produce red paint - carmine), blister beetles (cantharidin is isolated from which an blister patch is made).

Harm of insects in human life

The negative values ​​​​of insects are that they are carriers of dangerous pathogens of various diseases. On their paws, insects carry fungal bacteria, microbes and other harmful microorganisms that contribute to the decay of vegetables and fruits. They also debug larvae in food and even in the wounds of the person himself.

Abundance of insects. Insects are the most numerous class of animals, more than a million species are known. Calculations made by scientists showed 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.

Importance of insects in nature. Insects live on land and in fresh water wherever life is possible. They live even high in the mountains, in deserts and in the polar regions. Insects are not found only in the seas. In connection with the wide distribution of insects, their significance in nature is also diverse.

The life of many insects is closely connected with the life of plants. A huge army of these arthropods feeds on leaves, roots, stems and other organs and parts of plants, fruits and seeds. Herbivorous insects during mass reproduction damage or destroy plants in vast areas. However, the positive significance of insects in plant life is very great. So, ants contribute to soil formation. Bumblebees, bees, flies, some species of butterflies and beetles play a large role in cross-pollination of flowering plants.

Great importance have insects in matter cycle in nature. Fattening on plant foods, they themselves become the prey of other animals (for example, insectivorous birds). Insects such as gravediggers and dung beetles are of great sanitary importance.

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

Harmful insects include those that damage crops, forest and garden trees and other valuable plants, eat and spoil food products, technical raw materials (wood, leather, etc.), woolen clothes (larvae of moth butterflies feed on wool). Insects have been 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.

SIGNIFICANCE OF INSECTS

The value of insects in nature

Insects make up about 80% of all animals on Earth, according to various estimates, in the modern fauna there are from 2 to 10 million species of insects, of which just over 1 million are known so far. Actively participating in the circulation 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 the flower is the result of the joint evolution of plants and insects. The adaptations of flowering plants to attract insects are diverse: 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 - in bees and bumblebees, a brush and a basket on the hind legs, in megachil bees - an abdominal brush, numerous hairs on the legs and body.

Insects play an important role in soil formation. Such participation is associated not only with the loosening of the soil and its enrichment 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 the sanitary role and the circulation of substances in nature are performed.

They play a sanitary role the following types insects:

· coprophages - dung beetles, dung beetles, cowsheds;

· necrophages - dead-eating beetles, gravediggers, leather-eaters, meat-eating flies, scavengers;

· insects - destroyers of dead plant residues: wood, branches, leaves, needles - drill beetles, larvae of barbels, borers, horntails, centipede mosquitoes, carpenter ants, mushroom mosquitoes, etc .;

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

The value of insects in human life

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

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

Insect pollinators, representatives of many orders, among which an important place is occupied by hymenoptera, increase the yields of seeds, berries, fruits, flowers of many cultivated plants- fruit and berry, vegetable, fodder, flower.

The Drosophila fruit fly, due to its fecundity 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

Ladybug seven-spot (Coccinella septempunctata L.). A small black beetle, 6-8 mm long, with red elytra, on which 7 black round spots clearly appear, thanks to which the insect got its name. Beetles fly well, with amazing accuracy they find colonies of aphids, which they greedily eat. Immediately on the leaves or branches, the females lay heaps of yellow shiny eggs. Small black six-legged larvae emerge from them, which immediately begin to eat aphids, like adults. Where the cows settled, aphids are completely destroyed. Such a picture can often be observed in gardens, berry fields and fruit nurseries. Beetles hibernate in crevices of buildings, under fallen leaves, in bough grass and other places. In early spring, after overwintering, they leave their shelters, crawl out onto trees and begin to eat pests. AT favorable years ladybugs (they are also called ladybugs) multiply rapidly and eat not only aphids, but also others small pests. In search of food and water, they accumulate en masse near water bodies, on the coast of the seas, on rocks, crawl along roads, where a large number of them die under the feet of passers-by. At such times, cows should be saved from death, collected in special boxes made of thick mesh and stored in refrigerators or in basements in cold places in order to release them on plants damaged by aphids in the spring.

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

Insects cause enormous economic damage to mankind by eating crops, wooden buildings and other items made from materials of plant origin. These insects include many types of butterflies: apple and plum codling moth, apple and cotton moth, representatives of the family of night bats (destroy crops, cotton, corn, sunflower, beets, etc.), pine moth and Siberian silkworm (pests of coniferous forests). Great damage to forests bark beetles, lumberjacks and goldfish. Leaf beetles, weevils, caryopses and May beetles harm the green parts of plants. Chafer especially dangerous at the larval stage, which lasts 4–5 years. The larvae feed on the roots. herbaceous plants and trees. Devastating locust raids were a terrible disaster at the dawn of human civilization and affect the economy of many modern states. Termites cause very great damage, which, thanks to the fauna of intestinal symbionts, perfectly assimilate fiber, destroying a huge amount of wood.

The high number of insects is explained by their high fecundity and a perfect set of adaptations for survival in a wide variety of conditions. Almost all substances of organic origin are used by insects for food. Therefore, insects, as one of the most essential components in terrestrial ecosystems, play an enormous role in the transfer of matter and energy, utilize almost all substances supplied by plants and animals, and themselves serve as food for many vertebrates and invertebrates. Their role in the soil-forming process is enormous.

The practical importance of insects cannot be overestimated. Every year, 1/5 of the planet's crop goes to feed the army of pests. Hundreds of thousands of hectares of forests are destroyed by pests such as Siberian and gypsy moths, construction timber bark beetles, barbels, goldfish spoil. Various bloodsuckers carry deadly diseases and annoy people and animals with their bites.

Insects are a multifaceted miracle of wildlife, they have their own special purpose on Earth, which is difficult to overestimate. They are excellent pollinators, soil-formers, orderlies of nature, and what is important for humans - insects improve soil fertility, restrain the excessive spread of many agricultural pests, produce honey and medicinal substances, dyes juicy flowers, silk. More than half of our diet is plant-based. And 15% of it owes its harvest to pollinating insects. They also pollinate most plant foods for animals. In addition, we enjoy admiring the beauty of bizarre forms, patterns and colors of the body, as well as the grace of movements. Only a small part (about 1%) of insects causes involuntary damage to human activities. But this is nothing compared to the important role they play in people's lives and in maintaining natural ecological balance.

More than 80% of plants are pollinated by insects, and it is safe to say that the 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 - in bees and bumblebees, a brush and a basket on the hind legs, in megachil bees - an abdominal brush, numerous hairs on the legs and body.

Insects play an important role in soil formation. Such participation is associated not only with the loosening of the soil and its enrichment 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 the sanitary role and the circulation of substances in nature are performed.

The following types of insects perform a sanitary role: coprophages - dung beetles, dung beetles, cowsheds; necrophages - dead-eating beetles, gravediggers, leather-eaters, meat-eating flies, scavengers; insects - destroyers of dead plant residues: wood, branches, leaves, needles - drill beetles, larvae of barbels, goldfish, horntails, centipede mosquitoes, carpenter ants, mushroom mosquitoes, etc .; insects - orderlies of reservoirs feed on rotting organic substances suspended or settled to the bottom (detritus) - larvae of mosquitoes, twitchers, or bells, mayflies, caddisflies, purify water and serve as a bioindicator of its sanitary condition.

Beneficial insects, especially bees, play an important role in human life. Firstly, they contribute to the solution of a medical and biological problem - prolonging the life of people, and secondly, a socio-economic problem related to nature protection. These little friends and helpers of a person are an important link in the chain of factors that have a beneficial effect on strengthening his health. Silkworms are of great importance for humans, among which there are several cultivated species that provide raw materials for the manufacture of natural silk (mulberry and Chinese silkworms); cochineal mealybugs, which form natural carmine in their bodies; lac bug is a source of shellac. The world of insects is complex and diverse. Hence, it is of great interest to study their structure, development and life, especially insects with complex behavior: ants, bees, termites, folded wasps, which will no longer evolve in their intelligent life because they are highly organized beings.

The role and importance of insects in nature are enormous. The mere fact that the number of species of insects far outnumbers the species of any other group of animals, and that many forms are also capable of multiplying in myriad numbers, makes insects a powerful biological factor.

As shown by special calculations, the results of which, of course, are approximate - for every person on earth there are about 250,000,000 different representatives of this class. Moreover, this is not an indifferent mass, but organisms actively participating in a wide variety of biological processes.

Speaking about the positive or negative meaning of insects, it must be remembered that these assessments are often very subjective and reflect only our attitude to certain results of the life of insects. Sometimes the person himself, disturbing the balance in the historically established biological complexes, causes the mass reproduction of some kind of insect, leading to catastrophic consequences. In nature, there is not and cannot be absolutely harmful or absolutely harmful. beneficial species. And insect pests are just forms that cause direct or indirect damage to a person, and in some cases the "harmful" properties of a species turn out to be really harmful, while in others they bring great benefits to a person.

All of the above can be illustrated with a huge number of examples, but we will focus on only a few of them.

The positive activity of insects in nature is primarily expressed in the pollination of flowers by them. various plants. In this sense, their significance is extremely great. For example, about 30% of European flowering plants are pollinated by insects.

Bumblebee on a flower

Some plants are completely unable to reproduce without special pollinators. Clover giving in New Zealand excellent harvests, did not produce seeds at all until New Zealand bumblebees, which were absent there, were not introduced - special pollinators of clover. main role among pollinators Hymenoptera and especially bees and bumblebees play; second most important are Diptera and third are butterflies.

The importance of insects in soil-forming processes is great, especially termites and ants. These insects, as well as the larvae of many insects living in the ground, loosen the soil with their moves, contribute to its better ventilation and moisture, and enrich it with humus. The latter is associated with the destruction of plant and animal remains that accumulate in abundance on the soil surface. 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 corpses and excrement of animals, carried out by representatives of a special faunistic complex, is of great sanitary importance.

The role of insects is also huge as one of the most important links in the cycle of substances in nature. Many insects are part of various food chains. In almost every class of vertebrates one can find specialized entomophages, that is, forms that feed exclusively on insects. This phenomenon has received the greatest development in birds and mammals.

No less significant are the negative consequences of insect activity. So, many of them feed on living tissues of plants, causing significant harm. Damage caused by insects is sometimes very diverse and affects a wide variety of plant organs: root system, stems and trunks, leaves, flowers, fruits, etc. In some cases, this may be the destruction of plant tissue - gnaws, turning moves (moves gnawed in the leaves are called mines). In other cases, on the contrary, the presence of insects leads to the formation of galls, which are ugly growths of some parts of the plant - leaf blade, buds, stems. With a massive attack of pests, both 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.

It is in this area that the clash of interests between humans and insects most often occurs. Pests of agricultural crops and forest species cause enormous damage.

Failure to take precautions can lead to the introduction of pests into such areas. the globe where they were previously absent. Not finding in new conditions natural enemies, pests begin to multiply rapidly. The absence of protective reactions developed over a long period of time in plants on which the pest settles leads to the fact that the damage inflicted increases significantly.

The harmful properties of insects can sometimes be used by humans to their advantage. The successful experience of using insects to limit the spread of some plants (in Australia, for example, specially acclimatized leaf beetles destroyed St.

Sometimes the transfer is made by simple contact with insect transmitters, for example, when food is contaminated by them, etc. In this way, it spreads various diseases house fly ( Musca domestica), crawling through all sorts of dirt, capturing bacteria, helminth eggs and transmitting them to humans. In total, about 70 species are carried by flies. various organisms, many of which are causative agents of dangerous diseases (cholera, diphtheria, etc.).

Talking about practical significance Insecta, we should especially dwell on the forms directly used by man. Among them there are species that, in essence, have become domesticated.

Honey bees directly benefit humans - Apis mellifera and silkworm - bombyx mori; breeding them and obtaining products - the basis of two industries National economy- beekeeping and sericulture.

In addition to bees and the silkworm, some insects have a well-known technical significance. They deliver medicinal substances (Spanish fly cantharidin), colorants (different types worms, Coccinea, especially the Mexican cochineal, Coccus cacti, going to the manufacture of carmine), tannin (in ink nuts Cynipidae), varnish and wax (some worms), etc.

More and more greater value acquired by insects in the practice of agriculture and forestry in connection with the development and improvement of biological methods of pest and weed control. For this purpose individual forms(Hymenoptera: riders, wasps-hunters, some predatory and herbivorous beetles, etc.) specially acclimatize in disadvantaged areas. An example successful application such control measures is the importation into the CIS of the equestrian Aphelinus mail, which completely suppressed reproduction dangerous pest root system of apple trees - blood aphids ( Eriosoma lanigerum), which came to Europe from America. The mass reproduction of the citrus pest brought from Australia to America, and then to Europe, was stopped ladybug Rodolia. These beetles have been successfully acclimatized in various regions of the globe, including ours in the Caucasus. AT last years artificial breeding of such insects in industrial conditions and their mass release in pest breeding grounds are widely practiced. To fight harmful insects widely used and genetic method. The intensification of agriculture and forestry does not currently allow completely abandoning the use of insecticides. The future, however, undoubtedly belongs biological methods pest control.

These examples, like many others like them, well illustrate the idea of ​​the French entomologist R. Chauvin: "Insects are harmful to a person only as long as he does not use them as helpers and refuses to use the power of his mind to solve the problems put forward by their existence."

Literature: A. Dogel. Zoology of invertebrates. Edition 7, revised and enlarged. Moscow " graduate School", 1981