What harm from insects. Beneficial insects
Scientists paleontologists have long established the period of the appearance of insects on Earth. It was more than three hundred and ninety years ago in the middle of the Devonian period. It was then that the ancestors of modern insects, close to springtail springtails, appeared. Therefore, they are considered one of the most ancient inhabitants of the planet. Perhaps that is why these inhabitants of the Earth are so interesting to us. But why are insects so called?
Bugs and spiders: benefit or damage
Although, there are exceptions here: in the First world war fly larvae were used to cleanse wounds from suppuration. This technique was called larval therapy. The larvae not only removed suppuration, but also secreted allantoin, which contributed to the rapid healing of wounds.
In fact, insects do much more good than harm. There is a well-known theory that says: if suddenly all these insects die out, as dinosaurs died out, in a few years life on Earth will disappear! Why are insects useful?
1) They play their very important and irreplaceable role in the natural cycle of substances.
2) They pollinate plants, which then bear fruit.
3) Some species destroy pests that interfere with plants.
4) Able to deliver products for human life: honey, wax, propolis, silk, paint (bees, silkworms, lac insects, etc.).
5) Sometimes they themselves are food for people: for example, grasshoppers, caterpillars, crickets, ants and others.
6) Serve for the benefit of all living things. For example, there are soil formers. There are orderlies (dung beetles). They themselves are a favorite food of birds and some animals.
7) Decorate nature (for example, butterflies or dragonflies).
By the way, more than one million different species of insects have been described. They make up the most numerous class of animals inhabiting the Earth.
And there are small inhabitants of the planet absolutely everywhere, despite the weather and difficult climatic conditions. For example, caterpillars of one of the butterfly species - Gynaephora groenlandica - easily tolerate seventy-degree frosts. They live in Canada and Greenland.
On the origin of the biological term
Why did this name come about? The word has a root from the verb "cut" or "cut". This name is tracing paper from the Latin insectum. Literally, this word translates as “notched animal” or “notched animal”.
The Latin word is also tracing paper, but already from the ancient Greek language: "ἐντομή", which means "cut". In any of the translations of the word "insects" refers to the peculiarity of the body structure of these animals. The vast majority of insect bellies have notches, from which the name of the class comes.
There are also other names: vile, for example. But other options are less common. In Weismann's dictionary of 1731, the word "insect" is used only in conjunction with the word "reptile".
In general, small residents the globe received unfairly little attention in scientific papers compared to other animals. But their world is very diverse and very interesting. It is clear that without various insects and midges, life on Earth would be completely different. And would there be such a life?
Educator of the highest qualification category
Barinova Julia Alekseevna
Tips for parents
Most domestic and Western teachers are inclined to believe that preschool age is decisive for the further education of the child. environmental education must be carried out taking into account age and individual features children.
Children preschool age interested in the world of plants and animals. Satisfying children's curiosity, we can teach our children to distinguish between animal friends and enemies of man. However, it is important to avoid misconceptions about the role of an animal.
Indeed, among arthropods, it is insects that cause great harm to human health and farm animals, to numerous plants used in various sectors of the economy.
But there are also beneficial insects that need to be protected. It is not only about bees that give honey, or silkworms, from whose cocoons silk is extracted. You can meet many of these types of insects, the benefits of which are not known to everyone. And they are invisible friends of man.
I will talk about those that are easy to show children for a walk. Basic information about a beneficial insect must be communicated to children. They need to remember it appearance and knew what the insect is useful for.
Take for example forest red ants. In the forest, children will immediately notice an ant heap and see rather large ants scurrying into different directions.
Some children will want to delve into the anthill, stir up a loose pile and see what is inside under the randomly lying fragments of small twigs, pine needles that make up the ants' dwelling. There will also be those who take it into their heads to step on a heap and push through the nest of ants.
If an adult does not prevent these actions of children, the lives of the little friends of the forest will be damaged.
The children should be invited to watch the ants, and they will soon discover that many are dragging into the "house" the small caterpillars that constitute their main food. Children must be told that caterpillars harm trees and grasses, and that ants, destroying harmful caterpillars in large numbers, are of great benefit. Therefore, it is impossible to destroy the dwellings of ants, where their testicles and larvae are located.
A lot of interesting things could be told about the life of ants, but for preschool children, this elementary information is enough.
Other types of ants are garden black, as well as brown, yellow, etc. - harmful. Some harm the hives by eating honey and bee larvae, others (like a black garden ant) penetrate into a person’s dwelling, where they pounce on sugar, jam and spoil other food products.
Small beautiful beetles are often found in the forest or garden - ladybugs . They are easy to catch, put in the palm of your hand and consider. Children like the bright color of the bug (red or yellow) and black dots on the hard elytra, as well as the oval shape of the body, on which a small head with small antennae is visible.
If you put a bug on its back, it seems to freeze, having drawn its three pairs of legs to the abdomen, and remains motionless for some time. Then he begins to carefully move his antennae and legs, turns over and, spreading his wings, rises into the air.
Ladybugs and their larvae are of great benefit in forests, gardens and orchards, destroying harmful small insects – aphids. This should be shown to children. If you release a ladybug on a leaf with aphids, then she will begin to eat them in front of the children. First, you need to draw the attention of children to dying leaves inhabited by aphids: they usually curl and stun.
You can invite children to collect ladybugs and release them in the next orchard or to the boulevard, where traces of aphid activity are noticed. It will be feasible for the guys in public useful labor. However, it should be borne in mind that some types of ladybugs are harmful. For example, a 24-point ladybug harms potatoes, turnips, and beets.
In the forest, children can see a useful beetle - black ground beetle. This agile beetle is fast on the ground. It rarely flies, preferring to hide under the bark of old stumps or under stones. By placing the beetle in a test tube or glass jar, the children will consider his tenacious paws, on which claws are visible.
With them, the beetle relies on the unevenness of the soil and repels when running. The ground beetle has well-developed upper jaws, with which it seizes small insects. In search of prey, ground beetles come out of their shelters at night and destroy harmful insects. It should be emphasized that ground beetles are useful beetles. For example, the largest and brightest ground beetle, the krasotel (it is more common in the south), eats caterpillars of the gypsy moth butterfly, a serious pest of forests.
Of the useful beetles, one can also name dead-eater beetles that act as orderlies. These include, for example, beautiful gravedigger beetles . During a walk in the forest, they can be found under the fresh corpse of a dead bird, shrew, mouse.
Put the gravedigger beetle in a test tube or jar and show the children the extensions on its front and back legs that make it easier for it to burrow. Without going into details, you should tell the children that dead animals are buried with their spatulas in the ground, cleaned of wool and feathers, and then lay the dead animals in the meat of the testicles, from which the larvae come out and eat the body of the dead prey. If the corpses were lying on the ground, they would spread the smell of decay and be a source of infection. Therefore, dead-eater beetles do not need to be destroyed.
Many species of flies carry on their paws and proboscis pathogens - microbes. They sit on food, leave marks on the walls, on the glass of windows, contaminate food, bringing infection into it. Children know that flies must be fought. But there are among the flies and our friends. They must be able to distinguish from harmful flies and protect them as beneficial insects.
hover flies , for example, similar in color to the abdomen to wasps, often sit on the flowers of forest and garden plants or with a loud buzz fly around them. These are useful flies: their larvae, similar to small brightly colored leeches, destroy aphids in masses, crawling along the surface of leaves and stems of plants.
There are other useful flies. On the forest edges, on tree trunks and stumps, one can find rather large black flies with an elongated abdomen. This - ktyri. Their larvae live in the soil, where they attack caterpillars, May beetle larvae and benefit from this.
Yes, and adult flies lead a predatory lifestyle, destroying other insects: clinging to the caught prey with their feet, they pierce the body of their prey with a hard proboscis and suck out the liquid insides. These flies can be handled quite safely for examination. Children should know that it is impossible to kill ktyrs.
Of man's friends in the world of insects are noteworthy dragonflies. The graceful appearance of these insects, their fast flight and the bright color of the abdomen, cast with a metallic sheen, attract the attention of children. They admire the grace of dragonflies, which remind them of airplanes and helicopters. When a dragonfly sits on a branch of a bush or on a stalk of grass, the tenacity of its paws is noticeable. She clings tightly to the plant, and it has to be torn off with effort. Catching a dragonfly is not easy: it is very cautious and immediately notices the approach of a hand. With her large eyes, she is well oriented in space, picks up any movement. The strong jaws of a dragonfly indicate that the insect is a predator. If you present a stem or a thin branch to the mouth of a dragonfly, it will grab and squeeze the object with strong jaws. Dragonflies are voracious. They fly in different directions in search of food and manage to destroy many pests in a day.
If insects are small in size (for example, mosquitoes), the dragonfly eats them on the fly, it devours larger ones, sitting on a bush or reed (near the water).
Children should be given the opportunity to watch dragonflies, talk about the benefits they bring, pay attention to the beauty of their flight, a beautiful view.
So we will teach the guys already with early years be interested in the life of insects and treat them differently, depending on their role in human life and economy. It is necessary to explain to children that in nature each organism performs its function, maintaining the natural balance. Nature must be protected!
Irina Leonidovna Ermolaeva, a specialist in plant protection against pests and diseases, tells.
In our gardens there are not only visible enemies, but also friends. These are various predatory beetles, ground beetles, hoverfly flies, ladybugs, ants and spiders, which, eating, invisibly help us, destroying pests on different stages development.
To attract beneficial insects and to stimulate their active work, nectarifers should be sown, i.e. plants that attract such helpers. These are phacelia, mustard, buckwheat, carrot seeds, onions, etc. Moreover, it is necessary to create a flower-nectar conveyor - sow them in different dates between rows or empty spaces.
fly tahina
One of the many beneficial insects is the tahina fly. The range of pests that it destroys is simply huge, and its effectiveness is high. Suffice it to say that the number of silkworms, sawflies, leafworms, moths, tahini moths is kept under constant control. The survival and accumulation of these flies is facilitated by the presence of flowering carrots, parsnips, goutweed and other umbrella crops.
The body of tachin flies is usually covered with strong bristles, and therefore they are also called sand flies. The family of flies-tachin has about 5 thousand species.
Tahini flies find their hosts in different ways. Some types of flies lay their very small eggs on the surface of the leaf where the caterpillar feeds. Caterpillars, eating the leaf, swallow the eggs, then larvae appear inside the caterpillar, which feed on the body of the host insect, which leads to its death. Other species lay their eggs directly into the body of the insect host. And, finally, there are types of tahini, the larvae of which themselves find the owner and bite into his body.
Tahini flies lay a large number of eggs, and therefore one fly can kill many caterpillars.
Ants and spiders
Ants and spiders do a great job of destroying pests. Coriander and anise can be sown next to cabbage. When sown at the same time, they bloom from May to September. Their flowers feed many beneficial insects and do not attract butterflies whose caterpillars damage cabbages.
Ants are nurses. They build their houses in the soil and above it and are of great benefit. Numerous passages of ants make the soil looser, and this improves the breathing conditions for plant roots. Getting their own food, ants bring a huge number of insect pests and their larvae into the passages and chambers of the anthill: the inhabitants of only one anthill destroy an average of up to 20 million garden pests per year. But it is worth watching for an increase in the number of ants, this can lead to oppression of the garden, and because of the favorite delicacy of ants that aphids secrete, they also contribute to the settlement of aphid colonies. Here you need to think about whether to leave the ants in their areas or not.
Spiders. A significant part of the prey of spiders of the families of jumping spiders (Salticidae), funnel spiders (Agelenidae), wolf spiders (Licosidae), sidewalk spiders (Thomisidae) are such dangerous pests, like a harmful turtle, Colorado potato beetle, meadow moth, different kinds moths, many Diptera.
Attention! I want to warn you that beneficial insects, like pests, overwinter in the bark, leaves, in the soil on garden plot. And in the summer, you should not catch all the insects you see in the garden, because you can leave the garden without defenders - beneficial insects, which are called entomophages.
ladybugs
Everyone knows what a ladybug looks like, but not everyone knows what benefits it brings. She is fertile and lays eggs in small groups of 30, the eggs are yellow, similar to eggs. colorado potato beetle and hawthorn butterflies.
An adult beetle eats 100-200 aphids per day, the larvae are ten times more voracious than mites, whiteflies (Aleyrodidae) and mealybugs (Coccoidea).
Ladybugs will be attracted to our garden by plants of the Compositae family: daisies, tansy, or yarrow.
Ladybug Larva
ground beetles
These workers can be seen in the process of digging or loosening the soil. These are nocturnal predators that prey on insects living in the soil: moth pupae, moths, larvae of click beetles (wireworms), gall midges. Destroy slugs and caterpillars. The menu of one ground beetle per day is about one hundred moth larvae, 5 adult moth caterpillars and 5-6 weevil larvae. And the larvae are much more voracious than adults, they sit in dug holes and grab insects crawling past.
To have more ground beetles in the garden, take care of soil fertility. Those. apply in spring and autumn organic fertilizers, humus, etc.
lacewing
This is a gentle and slender insect. The color is pale green. Adult insects feed on the nectar of flowers, aphids, pollen, as well as the mites and aphids themselves, destroying up to 4000 individuals per day. The larvae suck spider mites and aphids. The lacewing prefers cool shady places covered with thickets of ferns for breeding.
flies-ktyrs
A two-centimeter ktyr cannot be confused with any other fly. Powerful paws armed with bristles and suckers. A strong proboscis, pointed at the end, protrudes from the flattened head. They ktyr can pierce even such a strong shell as beetles have.
Ktyri, destroying a lot of harmful insects, bring undoubted benefits. Their menu includes beetles, flies, fillies, leafhoppers, butterflies and even caterpillars. Not only adult insects are useful, but also larvae that live in the soil and destroy the larvae of click beetles, beetles and dark beetles, locust eggs and caterpillars that gnaw on the scoop.
Interesting. The largest ktyri reach 5 centimeters. You should not touch the ktyri with your hands - their bite is as painful as a prick of a bee sting.
Such flies are attracted to plants from the aster family - goldenrod, chamomile, daisies, as well as various types of mint - catnip, peppermint and spearmint.
Trichogramma
This is an egg-eater, the mass reproduction of which has already been put on an industrial basis. Trichogramma females lay their eggs in the eggs of many pests - apple codling moth, yellow and pale-footed gooseberry sawfly, meadow moth, cabbage scoop, cabbage whites and others.
Since these insects are very small, they take nectar from small open flowers such as anise, dill. A good shelter for them are plants of the celery family.
From the above, it follows that the more nursery plants in the garden, the less pest problems you will have. These plants can be placed along the edges of the garden or border areas with vegetables. It is necessary to select plant species in such a way that they bloom for a long time, replacing each other. Marigolds, alyssum, tansy, chamomile, daisies are suitable for this. Savory, lavender, hyssop, basil, rosemary, oregano bloom for a long time.
You can name many more useful insects - our helpers. But their number is still less than pests. Birds, frogs and toads, dragonflies, spiders - many animals help to keep the garden and vegetable garden clean from pests and healthy. But they themselves are not protected from chemicals.
Chemical treatments primarily destroy beneficial insects, since for a number of reasons they are more sensitive to chemistry and, in addition, their numbers are much smaller. Against the background of an abundant food base and the absence of natural enemies, the pests remaining after processing begin to multiply intensively. First of all, this applies to sucking pests - aphids and mites, which give several generations during the growing season.
This information is for lovers of chemistry and for those who consider it necessary to destroy everything that flies, crawls, jumps around the site.
Insects are ubiquitous. They live on land, in fresh water - where life is possible. You can not meet them only in the seas. Given this distribution, the question arises: "What is the role of insects in nature?"
Species Features
The number of animal species of the named class on the planet significantly exceeds the number of other groups. To date, more than 625 thousand of their species are known. The most common are common beetles, which have rigid forewings.
There is also a division according to the nature of nutrition. Three groups are distinguished among them:
- Those that eat other insects (ladybugs, mantises).
- Those that eat the waste of decomposition of plants and animals (dead eaters, gravediggers).
- Plant-eating (May beetle).
It is worth noting that some types of ladybugs are specially bred in the laboratory. This is necessary in order to later release them into greenhouses and gardens to destroy aphids.
Dead eaters and gravediggers are among the orderlies of nature. They prevent pollution of the environment by the waste products of decaying living organisms.
What's the use?
The role of insects in nature can be both positive and negative. Speaking about the benefits, it should be noted that:
- without insects, pollination of plants is often impossible;
- they participate in soil-forming processes;
- named living organisms support the cycle of substances in nature.
Pollination of plants
The value of insects in nature is great. And their positive activity, first of all, consists in such qualities as bumblebees, bees, butterflies, etc. It is known that some plant species are not able to reproduce without pollination. For example, clover, which in New Zealand gave good yields, nevertheless, could not produce seeds until bumblebees were brought into the country.
Soil formation processes
Termites and ants actively take part in loosening the soil. There are other insects that live in the ground, forming passages in it. By the way, without their activity, it becomes impossible to decompose the fallen coniferous plants. And this leads to the accumulation of peat-like layers, which makes the land infertile.
Squads of insects loosen the soil, enrich it with humus, and provide ventilation. Of no small importance is the destruction of excrement and carcasses of animals. After all, substances released during the decomposition of organisms pollute environment, including soil.
Circulation of substances
The role of insects in nature is larger than one can imagine. They take part in in nature. Much would not be on the planet if it were not for insects. Birds, for example, eat them. Some of their species eat only insects. Predatory animals, in turn, feed on birds. So the circulation of substances reaches a person.
negative activity
If you study what role insects play in nature, it is worth noting that they bring not only benefits. The negative results of their activities are as follows:
- destruction of plants;
- the spread of diseases.
plant destruction
There are cases when certain types of insects destroyed entire fields. Damage can affect different organs of plants. Sometimes not only leaves, fruits and trunks are destroyed, but also the root system.
Insects destroy plant tissue, make passages in it, which causes crops to dry out and die. As a result, entire plantations of the crop may be in danger of dying. Of particular danger is the mass reproduction of individual individuals. There are known cases of locust attacks on fields, as a result of which all plants encountered on its path were destroyed.
Pests include some species of butterflies and beetles, aphids, locusts and others. It is worth noting that this is the fault of the person. He does not always adhere to the rules of crop rotation, growing one crop for many years in a row in a certain place, which contributes to the reproduction of insects. Mankind actively fights pests through the use of chemicals that are sprayed on plants and soil.
Disease vectors
The role of insects in nature is also associated with danger. So, some of their species are carriers of pathogens. These are mosquitoes, mosquitoes, bedbugs and others.
Red Book
Given the importance of insects in nature, some of their endangered species are subject to protection.
To date, about 95 species that are on the verge of extinction are listed in the Red Book. Most rare insects are beetles (36 species). These include ground beetles, krasotely and others.
There are 33 species of butterflies in the Red Book - Apollo, pigeons, bears and others. 23 species of Hymenoptera are subject to protection. Among them there are seemingly common insects - bees and bumblebees. The remaining two species are dragonflies.
Interesting facts about insect breeding around the world
Many terrarium keepers breed insects, including grasshoppers and locusts. This is their hobby, which is not for everyone. ordinary people clear. In some countries, instead of cats and dogs, they prefer to keep big cockroaches. Maybe because they do not make a sound and do not interfere with households and neighbors. In addition, they are picky in nutrition, do not have wool and fluff.
In Australia, for example, praying mantises are pets. By the way, some residents simply put these insects on the curtains so that they catch flies.
In China, preference is given to the cultivation of crickets. This is not just a hobby, but a real entertainment. Fights and fights are held between crickets. The Chinese themselves are watching this with great pleasure. Swimmers are also raised. They are kept in aquariums and have a peculiar body structure.
As you can see, it is difficult to answer unequivocally what role insects play in nature. It can be positive and negative. Bees, bumblebees and other insects pollinate plants, taking part in their reproduction. Gravediggers and dead eaters destroy hazardous waste generated after the decomposition of dead animals. Locusts and aphids destroy plants. Mosquitoes and bedbugs are carriers of diseases. As you can see, the importance of insects in nature is great and varied.
In this case, it is also worth noting the aesthetic component. Indeed, even the most ardent opponent of all representatives of the described class of animals will involuntarily begin to admire the beauty of butterflies.
It is conditionally divided into three groups: harmful, indifferent and useful. But often the harm of many insects depends on the season and all kinds of conditions. For example, those annoying to people provide an invaluable service to the inhabitants of ponds and lakes: the larvae of these insects are an important source of food for fish.
Harm to humans and animals
Among the huge number of insects, there are many that cause serious harm to humans and animals. Blood-sucking insects that can carry pathogens of a wide variety of diseases can be very dangerous. An ordinary fly that has flown into human habitation can bring such dangerous diseases as dysentery, cholera, typhoid fever or roundworm eggs on its paws. The well-known tsetse fly is a serious enemy for those living in the tropics of the African continent: for humans, its bite is not fatal, but almost all domestic animals die from it rather quickly.
Numerous mosquitoes bring a lot of trouble to humans, but the most dangerous among them are malaria. Dragonflies and insectivorous birds help people fight mosquitoes.
Along the banks of rivers and in the savannahs South America there are mosquitoes, the bites of which entail cruel torment of people and animals. The bite of mosquitoes resembles a drop of boiling oil that has fallen on the skin, the victims of mosquitoes become completely unrecognizable. With a large accumulation, these insects penetrate the ears, nose, mouth, eyes.
Animal husbandry often suffers from horseflies and gadflies: big number These flying insects on pastures do not allow domestic animals to eat normally, causing a decrease in milk yield. In addition, the larvae of some gadflies can penetrate into internal organs and subsequently cause the appearance of purulent nodules.
Big problems for a person are delivered by red cockroaches. Prussians are not easy to get rid of, as they are very prolific. The danger of these insects lies in the fact that cockroaches are able to carry pathogens of dangerous diseases. Compliance with elementary sanitary norms in the apartment will help, along with the necessary processing, to get rid of these unpleasant "neighbors".
The food for bed bugs is human blood, so they appear at night and find the "victim" from a long distance by smell. During the day, bedbugs hide in crevices, behind wallpaper, ceilings and curtains. In addition to the trouble from bites, bedbugs are dangerous for humans as infections, so it is important for them to declare “war” immediately, perhaps even throwing away furniture or inviting specialists.
Fleas usually appear in the house from pets. Dangerous to humans as carriers of viruses and microbes. Disinfection of animal mats, regularly maintained cleanliness will eliminate the presence of these insects.
Many other representatives of insects can also live in a person’s dwelling, including: domestic ants, moths, wood lice, and various bugs. All of them also cause trouble for people, pets and plants.