Identify an insect by its appearance. Who are insects? VII. Consolidation of the studied material

To define an insect means to correctly attribute it to a specific detachment, family, genus, species. Pest control practitioners in agriculture and forestry need an accurate definition of the type of pest in order to recommend measures for its extermination; it is equally important to correctly identify the types of insects that are harmful to human health, for example, distinguishing the malaria mosquito from related species that are not carriers of malaria pathogens, etc.

To identify insects, special identification books have been created, consisting of identification tables. According to the tables included in the school identification atlas, it is possible to establish the belonging of an insect to a detachment and family. These tables are simplified by the fact that they only take into account the signs of large insects, more than 5 mm long. In the key table, the most characteristic features of a particular group of insects (order, family, etc.) are described and numbered; in parentheses is the number under which the opposite signs are listed, for example:

1(6) There are no wings or their rudiments.

6(1) Wings or their rudiments are present.

The definition begins with the number 1. In this case, first of all, it is necessary to establish whether the insect under determination has wings, at least in the form of rudiments, or whether they do not. If there are no wings, then point 1 is suitable and, therefore, you need to go to the next point 2. If there are wings, then point 6 is suitable and you must then go to the next point 7. In the future, again from the two opposite points, you must choose the appropriate on the signs and go to the next item after it. The definition is completed when the Russian and Latin names of the order or family are placed at the end of a suitable paragraph. The identified insect belongs to this systematic group.

In order to clarify the specific name of an insect, it is necessary to find a series of color drawings of insects from a given family using the link to the page and compare the identified insect and drawings. If the shape, color and size of the insect and its image in the atlas match, the definition can be considered complete, inscribe a label with the name of the insect and pin it on the bottom with the same pin.

However, it must be remembered that there are many insects that are very similar to each other. Therefore, in order to verify the accuracy of your definition, you must carefully read the description of the signs of an insect in the text placed next to the figure. It should also be borne in mind that insects are very variable in terms of such features as body size and color. According to these indicators, for example, males and females, spring and autumn forms of the same species are often distinguished. Therefore, only the most careful study of all the characteristics of an insect can guarantee against errors in the identification of common species.

Of course, not all insects can be identified by a short school atlas-identifier. If desired, you can use more detailed determinants or atlases of insects and use them to identify insects that are not in the school atlas. Only specialist entomologists working in zoological museums, who know insects well and have extensive experience in identifying them, can finally confirm the correctness of the definition. You can always turn to them for help.

The definition should begin with the key table of the main units. A total of 34 orders of insects are known. The key table includes 21 detachments. Orders with a limited distribution, small groups and orders of primary wingless insects, mainly consisting of small forms, are not included.

The Soviet state shows constant concern for the study, proper use and protection of nature. Each soviet man wants our rivers to be clean, the air fresh and transparent, forests healthy, and fields and meadows blooming and fertile. Where cities are being built, industry and agriculture are developing, concern for the conservation of nature is especially necessary. Therefore, in our country, laws have been issued prohibiting polluting environment exterminate valuable animals and plants.

A huge army of insects is an inseparable part of nature. The importance of insects in nature and the national economy is great and varied. They are necessary for nature, and if for a moment we imagine that insects have disappeared, then most plants will disappear after them, since there will be no one to pollinate them, many fish, birds, amphibians and reptiles will begin to die out, because they will have nothing to eat, etc. .

However, despite the great importance of insects, they are still very poorly studied. Therefore, it is currently difficult to draw a final conclusion about how one or another insufficiently studied species is harmful or useful.

Therefore, scientists came to the conclusion that insects should be treated with the same care as large vertebrates, many of which have already been taken under protection. Only specially trained workers can collect insects for museums and educational collections. It is important to remember firmly: collecting insects for your own entertainment means damaging nature. Such useless collecting is currently not allowed.

On the other hand, there are some types of insects that are officially recognized as serious pests that damage the national economy and human health. Widely known as a pest, the Colorado potato beetle attacks potato fields; cabbage is destroyed by cabbage butterfly caterpillars; the harvest of apples in orchards is reduced by codling moths; forest stands are eaten by caterpillars of Siberian and gypsy moths; pine crops damage rhizomes - larvae Maybug etc. Huge damage to animal husbandry is caused by blood-sucking insects - horseflies, mosquitoes and other Diptera, which, in addition, can carry pathogens of animal and human diseases, such as malaria.

Therefore, it becomes clear why, despite the careful attitude towards insects in general, special extermination measures are often carried out against their individual harmful species. The vast majority of insects do not cause harm, and they should be protected.

The study and definition of insects

Insects are the most numerous class of arthropod type. It is best to distinguish insects from other arthropods (crustaceans, arachnids, many-legged, etc.) by the number of legs - there are only 3 pairs of them. Most adult insects have developed wings that other arthropods do not have.

The world of insects is huge and diverse. It took a lot of work of scientists to streamline this diversity. Each insect has a scientific name in Latin, consisting of two words denoting the genus and species. These names are used by scientists of all countries when they write about this insect. In the atlas-determinant, in addition to Latin, there are also commonly used names of insects in Russian.

Insect species are combined into genera, genera - into families, families - into orders, which form the class of insects.

The main method of studying insects is to observe them in nature. Particularly interesting, for example, are visitors to flowers, which are of great importance as their pollinators. Some insects quickly fly from flower to flower, and it is difficult to keep track of them. Others remain on the flower for a long time, and during this time you can try to establish the type of insect by comparing it with color images. In cool weather, insects are less active and easier to observe. Beetles and some other insects with strong covers can be caught in glass jar, and after studying, release back to the plants. However, this cannot be done with butterflies - they will damage their wings on the walls of the jar.

The atlas-key includes information only about the most common insects, widely distributed in the European part of the USSR, and about a few rare species subject to protection. Small insects, less than 5 mm long, are not included in the book.

The external structure of insects

Before identifying insects, it is necessary to carefully study their external structure, choosing for this the largest representatives of different orders - butterflies, beetles and orthoptera. A 7x loupe or a binocular microscope is required for work. When determining insects, they should be handled with care, as they are very fragile and the slightest carelessness can lead to breakage of the collection item.

The body of insects is divided into 3 sections: head, thorax and abdomen. The chest and abdomen are divided into transverse rings - segments connected by soft membranes.

On the head there are eyes of a complex structure. The organs of smell and touch are the antennae, which consist of separate segments.

Scheme of the structure of an insect using the example of an orthopteran: 1 - head; 2 - eyes; 3 - chest; 4 - abdomen; 5 - wings; in - legs; 7 - ovipositor.

The shape of the antennae is an important feature in identifying insects. Antennae, consisting of long thin segments, are called filiform; antennae with an extension at the very end - club-shaped, with an extension in the middle part - fusiform; antennae with lateral outgrowths extending from both sides of the segments are called comb-shaped; cranked antennae are called with a sharp bend; if at the end of the antennae there are wide plates, then they are called lamellar.

Types of antennae: 1 - filiform; 2 - club-shaped; 3 - serrated; 4 - comb; 5 - pinnate; 6 - lamellar; 7 - cranked.

Mouth organs are important in identifying insects. Insects crush solid food with two mandibles, which are the main part of the gnawing mouthparts. Insects that feed on liquid food (juice, flower nectar, blood, etc.) usually do not have mandibles; their mouth apparatus consists of a proboscis - needle-shaped, like mosquitoes, or thick, like flies, sometimes very long, twisted, like butterflies. The mouthparts are covered from above and below by plates - the upper and lower lip

The structure of the oral organs of insects is very diverse. Sometimes there are both mandibles and a proboscis, such a mouth apparatus is called gnawing-sucking or gnawing-licking. If an insect pierces the outer integument before sucking, then its needle-shaped oral apparatus is called piercing-sucking. Some insects have underdeveloped mouthparts.

The thorax consists of three segments - prothorax, mesothorax and metathorax. The upper side of the thoracic segments is called the pronotum, mesonotum, and metanotum.

Legs are attached to the thoracic segments from below, which insects have 3 pairs. The main parts of the leg are called the thigh, lower leg and tarsus. The tarsus usually consists of several segments and ends with a claw. The legs of most insects are thin, running or walking. Legs of other types are distinguished by the following features: jumping legs are long, with a thickened thigh; swimming - wide, covered with rows of hairs; digging - short, thick, with teeth along the front edge; grasping - with spiked hips and lower legs.

Types of legs: 1 - walking; 2 - jumping; 3 - swimming; 4 - digging; 5 - grasping.

Wings are attached to the dorsal side of the mesothorax and metathorax. There may be 1 or 2 pairs. Sometimes the wings are missing. The wing plate is usually thin, membranous, reinforced with a network of filiform thickenings - veins. The front wings of some insects are strongly thickened and turned into elytra, which serve to protect the abdomen from above. The hind wings of such insects fold at rest and cover themselves with the front ones. On the surface of the wings of some insects there are hairs or scales.

At the end of the body there are often appendages in the form of thin tail filaments, claws, etc. Females often have an ovipositor. Wasps, bees, bumblebees and other hymenoptera have a stinger that is retracted inside the abdomen when at rest.

Working with collections

You can study the signs of insects using reference collections. Such collections are made especially for schools and other educational institutions, they are available in biological cabinets. There are large collections of insects in museums, scientific institutes, plant protection stations and other organizations that need these collections for their work.

Every student who wants to study insects from collections can do this in biological and entomological circles that work in schools. Houses of pioneers, in technical schools, scientific and educational institutes. Under the guidance of specialist entomologists, a beginner can quickly and profitably master the skills of identifying insects, and this is absolutely necessary before starting serious observations of insects in nature,

Appearance of various insects: 1 - earwig, 2 - scorpion, 3 - louse, 4 - stonefly, 5 - flea.

Catching insects in nature, as has been repeatedly indicated, should not be. However, it is possible to work with insects that are officially recognized as serious pests that must be destroyed, such as the Colorado potato beetle. In addition, thematic observations can be accompanied by the collection of dead insects. Many insects die in puddles after heavy rains or in streams when irrigating agricultural land. These insects must be removed from the water, washed with a soft brush and pricked on pins, later determining their names. In the evening, insects fly to light sources and often die from contact with them. In autumn, many insects die a natural death. At this time, you can collect a lot of dragonflies, flies and hymenoptera on paths and roads, near walls and fences, where they are carried by the wind.

Collected materials must be put in order without delay. Dead insects removed from the water, while they are not dry, should be pricked on special entomological pins, straightened, and after drying, placed in entomological boxes. Pins and boxes are sold in zoological shops. If entomological pins are not available, then insects can be stored on layers of cotton wool packed in paper envelopes. These envelopes are placed in boxes with tight-fitting lids and a little naphthalene is placed there to protect dry insects from skin beetles and other pests. Dry insects are softened before being pierced with pins by placing them in a jar of wet sand for a day.

When working with reference collections and your own collections, it is important to familiarize yourself with the rules for pinning insects. Insects are pricked either in the middle of the chest (butterflies, flies, hymenoptera), or in the base of the right elytron (beetles, cockroaches, orthoptera). Bed bugs are pierced in the middle of the shield. Butterflies are straightened on a special spreader or on homemade machine, for example, on a smooth board, in which there are slots for the body of a butterfly. Butterfly wings are fixed in the desired position with strips of paper, which are placed on top and secured with pins. In the same way, you can straighten dragonflies, orthoptera, hymenoptera. In beetles, legs and antennae are fixed with pins in the desired position.

Each insect is provided with a label - a rectangle of white paper, on which there is data on the place and time of the capture of the insect. The label is pinned on the same pin from below.

Fully prepared insects are stored in entomological boxes with a bottom of peat, cork or foam.

Collections are stored in cabinets in a dry place. Sometimes pests of collections penetrate collection boxes, for example, beetles - dark beetles and leather beetles that eat dry insects. To protect the collections, a gauze bag with mothballs is pinned to the corner of the box.

Appearance of various insects: 1 - cockroach, 2 - praying mantis, 3 - mayfly, 4 - lice.

Definition of insects

Definition starts with a number 1 . In this case, first of all, it is necessary to establish whether the insect being determined has wings, at least in the form of rudiments, or whether they do not. If there are no wings, then point 1 is suitable and, therefore, you need to go to the next point 2. If there are wings, then point 6 is suitable and you must then go to the next point 7. In the future, again from the two opposite points, you must choose the appropriate on the signs and go to the next item after it. The definition is completed when the Russian and Latin names of the order or family are placed at the end of a suitable paragraph. The identified insect belongs to this systematic group.

Key to the main units

2 (3) Dark brown small insects with a laterally compressed body. Hind legs thickened, jumping. They live in animal burrows and sometimes in residential buildings. The larvae develop in wet plant debris....... Flea Detachment (Siphonaptera)

3 (2) White or yellowish small insects with a flattened body. The hind legs are not hopping.

7 (28) The mouth apparatus is gnawing, i.e., there are well-developed mandibles, or gnawing-licking, when there are not only mandibles, but also a proboscis designed to collect nectar.

8 (11) The forewings are dense, keratinized elytra without venation.

9 (10) At the end of the body there are movable claw-like appendages. Live in upper layers soil, in wooden buildings, under the bark of withered trees ......... Earwig Squad (Dermaptera)

10 (9) There are no claw-like appendages at the end of the body ............................. Order Coleoptera, or Beetles (Coleoptera)

11 (8) The front wings are thin, membranous, and if slightly compacted, then with clearly visible venation.

12 (13) Antennae very short, inconspicuous. Wing venation reticulate. Large insects with long wings ............................................ Dragonfly Order (Odonata)

13 (12) Antennae well developed, longer than head.

14 (15) The head is extended downward like a beak. Adult insects are found in damp meadows and forests. The larvae develop in the soil.... Scorpion Squad (Mecoptera)

15 (14) The head is not extended into the beak.

16 (21) The front wings are dense, leathery, well distinguished from the membranous hind wings.

17 (18) The forelegs are strongly modified, adapted for grasping prey. They live among plants and lie in wait for other insects that serve them as food. Praying Mantis Squad (Mantoptera)

18 (17) The front legs are not prehensile.

19 (20) The hind legs are thickened, jumping, or the front legs are digging, reminiscent of the front legs of a mole ....................... Order Orthoptera (Orthoptera)

20 (19) Fore and hind legs not changed, walking. They live in forests, in dried leaves on the soil, some species are common in houses ....................... Detachment Cockroaches (Blattoptera)

21 (16) The front wings are thin, membranous, the same as the hind wings.

22 (27) The veins on the forewings and hindwings form a dense, fine-meshed network consisting of several tens of cells.

24 (23) The antennae are attached in front of the eyes, i.e., closer to the mouth organs.

25 (26) The prothorax is strongly elongated. On the cutting edge wing at its top has a dark spot. The larvae live in dead fallen leaves, under the bark of trees....... Camel Detachment (Raphidioptera)

26 (25) The chest is not elongated. There is no dark spot on the forewings. Larvae live in streams, and adult insects live among vegetation ............... Lopfly Squad (Megaloptera)

27 (22) The veins on the fore and hind wings form a large-meshed network, consisting of at most 10-15 cells ............. Order Hymenoptera (Hymenoptera)

28 (7) The mouth apparatus is not gnawing, i.e. the mandibles are not developed, usually there is a proboscis. Sometimes all parts of the oral apparatus are underdeveloped.

29 (30) The front wings at the end are thin, membranous, transparent, the rest of the surface of the wings is thickened, leathery ........ Detachment Hemiptera, or Bedbugs (Hemiptera)

30 (29) Forewings entirely thin, membranous, transparent.

31 (34) The wings are completely covered with hairs or scales.

32 (33) The wings are covered with easily washable scales that form a pattern. The proboscis is spirally twisted, sometimes underdeveloped ............. Squad Lepidoptera, or Butterflies (Lepidoptera)

33 (32) The wings are covered with hairs. The oral organs are underdeveloped. The larvae live in water bodies, most of them in tubes that they construct from grains of sand, shells, plant particles, etc. ............................................... Detachment Caddisflies (Trichoptera)

34 (31) The wings are smooth, without a cover of hairs and scales, occasionally such a cover is present only along the veins.

35 (36) Only 1 pair of wings is developed .... Order Diptera, or Mosquitoes and flies (Diptera)

36 (35) 2 pairs of wings are developed. At small species, forming colonies on plants, wings are often absent.

37 (38) Mouth apparatus in the form of a stabbing proboscis. Wings at rest fold roof-like. Often the wings are missing. They live on plants, feed on their juices, usually form colonies. They carry pathogens of viral diseases. Order Homoptera (Homoptera)

38 (37) The oral apparatus is underdeveloped, there is no proboscis.

39 (40) Antennae shorter than head. The front legs are elongated. The larvae live in slow-flowing water bodies. Adult insects appear in the spring-summer period, often forming swarms. They live a very short time.... Mayfly Squad (Ephemeroptera)

40 (39) The antennae are much longer than the head. The forelegs are no longer than the middle and hind legs. Larvae live in streams and fast rivers ............... Detachment Vesnyanka (Plecoptera)

At the head is mouth - sense organ. There is antennae, some animals have proboscis. The eyes have a special structure: insects are short-sighted, but they perfectly see movement, color. Limbs are located on the chest insects have 6 legs. At the same time, the paws serve not only for movement. Some use them to collect pollen, others for hunting and jumping, and some for swimming or sensing sounds. The abdomen contains internal organs.. There is everything to ensure the life of the body. One of distinguishing features is the presence wings. Most members of this class can fly.

With the exception of the seas, insects are found almost everywhere: in swamps, meadows, forests, mountains, and even in human habitation. Their diversity is great, but they are distributed unevenly around the world.

Scientists divide insects according to the method of reproduction into 2 groups:

1. when a larva appears from an egg, resembling already adult insect(Fig. 2);

2. The larva turns into a pupa and then turns into an adult (Fig. 3).

Rice. 2. The first method of reproduction ()

Rice. 3. The second method of reproduction ()

Found in nature herbivorous insects. They feed on plants, pollen and plant sap. These insects include. They are lovers of disguise. It is difficult to notice the Stick insect among the trees and foliage. When danger threatens, he can easily lose his leg, a new one will still grow (Fig. 4).

Rice. 4. Stick ()

They feed on plant sap. Their males are the loudest singers among insects. The chirping sounds like the whistle of a locomotive. There are very cicadas large sizes(Fig. 5).

The variety of butterflies is simply amazing. Their wings are like magnificent flowers. They pollinate plants by flying from one plant to another. Nectar is obtained with a proboscis.

Herbivorous insects also include aphids, bees, leaf beetles.

Meet predatory insects . They feed on other insects and their larvae. A prominent representative of predators is (Fig. 6). He can lie in wait for his prey for hours, merging with the terrain. Then instantly attacks the victim.

Who doesn't know ladybug? It turns out that she is also a predator, only useful to humans and outwardly pretty. Destroys aphids, spider mites.

And how the flight of amazing creatures fascinates us - dragonflies(Fig. 7)! These helicopter pilots develop pretty decent speed, they can go on a long journey. The predator likes to eat mosquitoes and other insects.

Rice. 7. Dragonfly ()

Among predators there is a swimming beetle, ground beetle.

It should also be considered omnivorous insects. These animals can feed on vegetation as well as other animals and even their blood. For example, a cricket (Fig. 8) eats leaves, but at a meeting it can eat its rival.

Among the omnivorous insects there are bloodsuckers. They feed on the blood of humans and animals. These are mosquitoes, horseflies, midges.

Others chose the corpses of other animals as food for themselves. They lay their eggs there. These include gravedigger beetle(Fig. 9) , carrion beetle(Fig. 10).

Rice. 9. Gravedigger beetle ()

Rice. 10. Corpse-eater ()

There are even insects that do not disdain to eat the remains of human and animal life. This is a dung beetle (Fig. 11) and a scarab.

Rice. 11. Dung beetle ()

Insects that live in families are called social insects. Who among us has not seen at least once a bee family or an anthill? These insects live in their states, there are their own rules and laws. bee family- this is a well-functioning mechanism, where each individual has his own responsibilities. There is a main queen, drones, worker bees. Each family member knows his place.

Ants- the most famous social insects. Anthills are entire cities in which a real economy is arranged. There is a female, males, worker ants, and also soldiers. Some species of ants keep aphids in their dwellings as dairy cows.

termites also social insects. Their lifestyle is similar. These insects are even confused with ants, although their ancestors are cockroaches.

Bumblebees and wasps are considered social insects.

Among insects there are those that benefit. The man has been breeding for a long time silkworm, it produces silk threads (Fig. 12).

Rice. 12. Silkworm ()

Also, a person is engaged in breeding domestic bees to collect honey.

Lacquer bug can produce natural resin and paint.

Among insects, there are pollinators of plants that contribute to the reproduction of plants, and hence a good harvest.

Some Insects are beneficial in that they destroy garden and garden pests. This firefighter beetle(Fig. 13), fly- hoverfly(fig. 14), lacewing(Fig. 15).

Rice. 13. Firefighter beetle ()

Rice. 14. Hoverfly fly ()

Rice. 15. Goldeneye ()

There are insects that are involved in the formation of soil. They loosen the earth, helping it to be saturated with oxygen.

Insect orderlies process the remains of animals and plants.

Many of the insects are food for other animals.

There are outright pests in the world of insects . These include mole. Its larvae eat wool, which means they spoil things (Fig. 16).

Many insects damage and destroy crops. This locust(Fig. 17) , Colorado potato beetle(Fig. 18) , leaflet(Fig. 19). Dealing with their invasion is quite difficult.

Rice. 18. Colorado beetle ()

Rice. 19. Leaflet ()

Destroy buildings, spoil furniture grinder beetle(Fig. 20) , barbel beetle(Fig. 21) .

Rice. 20. Grinder beetle ()

Rice. 21. Barbel beetle ()

interesting facts from their lives.

For example, one of the smallest insects is North American featherwing. In this bug, the body length does not even reach 1 mm.

The longest is tropical stick insect. Can have a body up to 36 cm.

Some night butterflies have a wingspan of 32 cm. They are also record holders.

Or the sea water strider, is perhaps the only insect currently known that lives in the sea (Fig. 27).

Rice. 27. Water bug ()

The largest beetle on the planet - titan beetle from South America (Fig. 28). It can reach the size of a hamster. Body length is up to 22 cm.

Rice. 28. Titan beetle ()

Tiny stinging insects woodlice flap their wings at an incredible rate of 62,760 times per minute.

dragonflies are the fastest flying insects. The speed of their movement can reach 50 km / h.

In the southern United States there is seventeen year old cicada. Its larvae burrow into the soil, where they live and grow. And only after 17 or 13 years they are born.

Did you know that ants never sleep? Butterflies taste food with their hind legs. Crickets have ears on their front legs.

A female cockroach can lay over 2 million eggs in a year. In addition, a cockroach can live for 9 days without a head.

The list of interesting facts from the life of animals can go on and on.

The following lesson will help you get an idea about the topic “Pisces. Signs of fish. On it we will consider animals for which the water element is their home. We learn the features of their structure, habitats and features fish.

Bibliography

Samkova V.A., Romanova N.I. The world around 1. - M .: Russian word.
Pleshakov A.A., Novitskaya M.Yu. The world around 1. - M .: Education.
Gin A.A., Faer S.A., Andrzheevskaya I.Yu. The world around 1. - M .: VITA-PRESS.

Mir-nasekomyh.ru ().
Maaam.ru ().
Micromirok.ru ().

Homework

Describe insects. Name the representatives.
Describe the structure of insects.
What interesting facts do you know about insects?
* Prepare a report on the topic: What is the most voracious animal? Wolf, goat, dragonfly. Prove it.

Main article: External insect morphology

Insect morphology
A- head B- breast C- abdomen
1. antenna
2. eyes (lower)
3. eyes (upper)
4. compound eye
5. brain (cerebral ganglia)
6. prothorax
7. dorsal artery
8. trachea
9. mesothorax
10. metasternum
11. front fender
12. rear fender
13. midgut (stomach)
14. heart
15. ovary
16. hindgut (intestine, rectum and anus)
17. anus
18. vagina
19. abdominal ganglion
20. malpighian vessels
21. pillow
22. jaws
23. foot
24. shin
25. thigh
26. swivel
27. fore-gut (crop, gizzard)
28. thoracic ganglion
29. basin
30. salivary gland
31. subesophageal ganglion
32. oral apparatus

Body dimensions are 0.2-330 mm (in modern representatives), usually in the range of 1-50 mm. The body-covering cuticle is part of the skin, forming a dense outer shell, or exoskeleton, but in some cases it is soft and thin. The outer cuticle is subdivided into separate scutes - sclerites (sclerites), and due to its density, it is favorable for the development of various formations on it - impressions, grooves, tubercles, ribs, small hairs - chaetoids etc. Movable skin hairs are also attached to the cuticle - hats sometimes having the character of bristles or scales.

The coloration of the body and its parts is very diverse, depending on the pigments located in the cuticle or the hypodermis underlying it, or due to optical phenomena associated with the structure of the cuticle. In view of the great durability, the optical and cuticular pigmentation remains almost unchanged after death; hypodermal pigment, on the contrary, quickly collapses. Often the pigment forms stripes along or across the body, in the latter case they are called bandages (fasciae). This is often associated with the phenomenon of mimicry.

The body of insects is divided into three segmented sections - the head, thorax and abdomen. Each segment is divided into four parts - the upper half ring is called tergite, the lower semiring is called sternitis, and the side walls pleurites. When designating the relative position of body parts and organs by the terms "dorsal" ( dorsalis) denote the upper side of the body, and "ventral" ( ventralis) is the bottom side. They also distinguish the mesosoma (in ants from three thoracic segments and the first abdominal segment of the propodeum) and metasoma (stalk and abdomen).

Head

Head ( caput) is outwardly non-segmented, but occurred as a result of the fusion of 5 segments during the oligomerization of the body. The preserved limbs of these segments are antennae, or antennas first (antennae) and 3 pairs of oral jaws - non-segmented upper jaws, or mandibles (mandibulae), segmented mandibles, or maxilla (maxillae) and jointed, outwardly unpaired underlip (labium), which is the second pair of lower jaws that have merged with each other. There are several types of oral organs, of which the primary is gnawing, designed to tear and absorb more or less solid food. In the process of evolution, several modifications of this initial type for the consumption of liquid food arose, which are arranged differently in different sucking groups of insects. In some cases, sucking is associated with a puncture of the food substrate and occurs piercing-sucking mouth apparatus (bugs, aphids, mosquitoes, etc.), in others, eating is not accompanied by a puncture, as, for example, in butterflies. A special modification is muscoid a type of mouth apparatus that arose in flies and adapted to the consumption of both liquid and solid food. Another way of development of the original oral apparatus is observed in cryptomaxillaries, the lower lip of which has merged with the so-called. oral folds, forming paired jaw pockets into which the mandibles and maxillae are immersed.

The solid foundation of the head is cranium (epicranium). On the head, the front surface is distinguished - forehead (frons), which goes from above to crown (vertex) and further back - back of the head (occupied). In front of the forehead lies a well-isolated plate - casing (clypeus) and further forward (down) - upper lip (labrum), a movable lamellar skin protrusion that covers the oral organs from above. On the sides of the head, under the eyes, distinguish cheeks (genae), posteriorly passing into whiskey (tempora), and below lies throat (gula). On the sides of the head are compound eyes (oculi), consisting of many visual units - ommatidian and are the main organs of vision. In addition, between the compound eyes there are usually 1-3 simple eyes, or peephole (ocelli). Depending on biology, the position of the head is not the same. Distinguish hypognathic head ( caput hypognathum) - with mouthparts facing down, like legs, and prognathic head ( caput prognathum) - with mouthparts facing forward. The first type is usually characteristic of herbivores, and the second - for predatory insects.

Types of insect antennae

The antennae sit on the sides of the forehead, between the eyes or in front of them, often in a well-separated antennal cavity. They are very diverse, characteristic of different groups of insects. Basically, the antennae consist of a thickened basal segment called handle (scapus), followed by leg (pedicellus), and starting from the third segment, the main part is located - flagellum (flagellum). There are several types of antennae (see fig.).

Breast

Breast ( thorax) consists of three segments - anterior, middle and metasternum (pro-, meso-, metathorax). The thoracic tergites are called backrest (notum), and sternites - breast (sternum). Accordingly, 3 segments of the chest are distinguished anterior, middle and metanotum (pro-, meso-, metanotum) and also anterior, middle and metasternum (pro-, meso-, metasternum). Each thoracic pleurite is subdivided by a suture into at least two sclerites - anteriorly epistern (episternum) and behind epimer (epimerum). Attachment to the chest of the organs of movement turns it into the locomotor center of the body, increases its size due to the development of powerful muscles and a strong change and complication of the sclerites described above.

insect leg

Legs ( pedes) are attached to the chest from below, usually sit in the coxal cavities and consist of coxa (coxa), swivel (trochanter), hips (femora), shins (tibia) and paws (tarsus). The coxa and swivel provide the necessary mobility to the leg. In some cases, the trochanter consists of two segments. The thigh is the largest and strongest part of the leg, as it has powerful muscles. Its articulation with the lower leg is called knee, and the part adjacent to it - knee (geniculus). The tibia is approximately equal in length to the thigh, but thinner, equipped with spikes ( spinae), and at the top spurs (calcariae). The tarsus is usually dissected, consists of 2-5 segments, has a pair of claws at the apex ( unguiculi), between which there is a wide sucker - arolyus (arolium) or narrow empodium (empodium). According to the way of life, the legs have undergone a variety of specializations, therefore, several types of them are distinguished.

Wings

With the improvement of flight from relative independence, insect wings “transitioned” to coupling with each other in various ways, functioning as a single organ with the main load shifting to the first pair. In other words, there was a process dipterization(from the Latin name of the Diptera order). With further evolution, the back pair is reduced in size, and then lost. The highest stage of insect flight appears - morphological diptera. All of the above determines the outstanding role of the structure of the wings in the classification and understanding of the evolution of insects.

Abdomen

Abdomen ( abdomen) consists of many, generally of the same type, segments, initially from 10, not counting the tail component - telson, but only some primary wingless and embryos have it in this form. Often the number of segments is reduced to 5-6 or less. Segments VIII and IX contain genital openings and very often external genital appendages, so these segments are usually called genital. The pregenital segments in adults, as a rule, are devoid of appendages, and the postgenital segments have only a developed tergite of the X segment, while the XI segment is reduced and its characteristic appendages - churches (cerci) have moved to the X segment. The structure of the church is very diverse, and higher forms they are atrophied. The remains of postgenital segments are sclerites lying dorsally around the anus - from above anal plate (epiproctus), on the sides and bottom lower anal sash (paraproctes). Sometimes (cockroaches, earwigs) the X tergite is called the anal plate. The appendages of the genital segments are in the male stylus (styles) - on the IX sternite, the female has an ovipositor ( oviductus) - paired outgrowths of the genital segments, which are modified limbs. IX male sternite forms hypandrium, or genital plate (hypandrium), but often the genital plate is called the last visible sternite in general, which in females of some hymenoptera is turned into a sting, although it is also used for its intended purpose). With the reduction of the real ovipositor in some groups (for example, in many beetles), a secondary, telescopic ovipositor arises from the apical segments of the abdomen, greatly reduced in diameter.

At the end of the male's abdomen is the copulatory apparatus, which has a complex and incredibly diverse structure in different orders. Usually it contains an unpaired part - the penis ( penis), which has a strongly sclerotized end part - aedeagus (aedeagus). The structure of the copulatory apparatus is of great importance in systematics, since its structure differs markedly even in twin species; often its study allows solving the most difficult problems of classifying genera, families, etc.

Internal structure

The entire life cycle, called generation, proceeds in different species for unequal time. Many species have a short generation duration, give one, two or three generations in one year and are called, respectively, one-, two- and three-generation. In others, one generation lasts for many years (for example, in a black cockroach, development lasts 4 years, and in a seventeen-year-old cicada, respectively, 17 years!). Another essential aspect of the life cycle of species is the time of occurrence in nature of certain phases of development. Thus, wintering of species living in the temperate zone can take place at the stage of eggs, larvae, pupa or adults; Accordingly, the time of the flow of other phases during the growing season changes. Consequently, species can differ from each other not only in the number of generations per year, but also in the time of individual stages of development, that is annual cycle.

Sometimes the annual cycle is complicated by a delay in the development of one or another phase - diapause accompanied by a decrease in metabolism and cessation of nutrition. Outwardly, it gives the impression of stopping development. Diapause is controlled by both external (temperature, day length, etc.) and internal (hormonal) factors, being one of the forms of insect adaptation to life in countries with sharp seasonal climate changes. Many diapasic insects during forced development without diapause (for example, under laboratory conditions) experience disturbances in ontogenesis or die.

It goes without saying that there are transitions between all the types of specialization considered, but, contrary to expectation, they are not so numerous.

habitats

Insects inhabit the vast majority of known terrestrial biotopes, occupying inhospitable ecosystems such as highlands, deep caves, and emerging ecosystems of newly formed volcanic islands. Marine insects are also known, belonging to a special family of water striders from the order of Hemiptera (besides them, other, typically freshwater bugs, rarely settle in coastal salt waters).

The selectivity of stations (habitats) is a very essential and characteristic property of insects. Each species has its own set of stations - in some cases diverse, in others limited by ecological limits and sometimes reduced to a single type of habitat. However, often a species is not limited to settling in only one station: a regular change in species of their habitats is manifested. Change of stations can be zonal, vertical, seasonal and annual.

The zonal change of stations is characteristic of many transzonal species (that is, species whose range crosses several natural zones): when moving north of the range, drier, well-heated open habitats are chosen, while when moving south, more humid and shaded stations are settled, often with dense vegetation. A special form of zonal change of stations is the zonal change of stages - the transition in the dry parts of the range of terrestrial species to an underground way of life. The vertical change of stations is similar to the zonal one, but is typical for mountainous conditions. If mountain system it is supported by arid landscapes - steppes or deserts, and the lowland part of the areal is moved away from the mountainous north, then with an increase in the level, the species move to more humid habitats. When the lowland and mountainous parts of the range come into contact, an increase in the vertical level causes the movement of species from more humid habitats to less humidified and more open ones.

Seasonal and annual changes of stations occur already in time and are the result of forced migrations of the species as a result of changes in the microclimate, weather conditions and vegetation conditions. The first is typical for areas with hot summers and consists in the transition to more humid stations. The annual change of stations is caused by the deviation of climatic indicators from the average norm and leads in dry years to the movement of a number of species to wet stations and, conversely, in wet years to movement to dry stations.

The ecological basis for changing stations is strict obedience to one's ecological standard. As a result, the type of inhabited stations changes, which ultimately leads to a change in the ecology of the species, stimulates intraspecific differentiation, and becomes a factor in evolution. It is not uncommon for a species to be represented by different subspecies in different zones or even differentiate into two very closely related species.

A geographically enlarged station is an area. For many insects, continuous ranges are known, although in the class, as it turns out in Lately, a relatively high proportion of twin species, sometimes differing only in biochemical features. As well as the ranges of other wild animals, the range of insects is characterized by belonging to one or more zoogeographic regions. Some researchers believe that it is possible to create a single detailed scheme of zoogeographic zoning acceptable for all insects. Others believe that the creation of such a universal scheme is impossible, since even such a taxonomically unified group as insects does not represent something unified in terms of patterns. geographical distribution. Therefore, it is pointless to try to create a single zoogeographic map, but maps should be developed for individual environmental groups insects. In particular, such a map for rheophilic amphibiotic insects (most mayflies) is completely incomparable with the map for herbivorous terrestrial insects and differs significantly from the map for limnophilic amphibiotic insects, such as dragonflies.

For general characteristics the range locations of a wide variety of insects usually use the widely recognized names for major land divisions: Palearctic, Nearctic, Holarctic, Amphipacific Sector, Ethiopian Region, Oriental Region, Arctogea, Neotropics, and Australia Region.

reproduction

Insects have separate sexes. The reproductive organs of the female are usually represented by paired ovaries and oviducts stretching along the sides, which merge into one unpaired duct that flows into the vagina. Females have seminal receptacles and accessory sex glands. Males have paired testicles, from which the vas deferens extend along the sides of the body. In the lower part, the vas deferens expand, forming seminal vesicles designed to store sperm. The seminiferous ducts are combined into a common ejaculatory canal, which opens on the copulatory organ, which is capable of increasing or extending. The adnexal glands secrete seminal fluid.

sense organs

Vision

Infraclass Two-tailed (Diplurata) Detachment of Two-tailed (Diplura) Infraclass Ellipurids (Ellipura) Order Springtails (Collembola) Order Bessyazhkovye (Protura) Infraclass Bristletails (Triplura) Order Bristletails (Thysanura) Order Archaeognatha Order Monura (Monura) † Order Carbotriplurida † Infraclass Winged (Pterygota) Cohort Paoliiformes Order Paoliidae (Paoliida) † Cohort Panephemeroptera Subcohort Protephemeroidea (paraphyletic taxon) Order Protephemerida † Order Syntonoptera † Subcohort Euephemeroptera Order Permoplectoptera † Order Mayflies (Ephemeroptera) Cohort Paleodictyoptera (Protorrhynchota) Superorder Palaeodictyoptera Order Palaeodictyoptera (Palaeodictyoptera) † Superorder Panmegasecoptera Order Megasecopterida † Order Eudiaphanoptera † Order Archodonata † Cohort Bimotor (Bimotoria) (dragonflies and related groups) Subcohort Meganisoptera Order Geroptera (Geroptera) † Order Meganeuroptera (Meganeuroptera) † Subcohort Nodiaalata Superorder Permodonata Order Protanisoptera † Superorder Triadophlebiina Order Triadophlebioptera † Superorder Stigmoptera Order Protozygoptera † Order Dragonflies (Odonata) Cohort Newwings (Neoptera) Subcohort Stoneflies (Plecoptera) Squad Cockroaches (Grylloblattodea) Squad Mantophasmida (Mantophasmida) Superorder Earwigs (Dermapteroidea) Squad Embi (Embiidina) Squad Leather-winged (Dermaptera) Superorder Cockroaches (Pandicyoptera) Squad Pratarakanas (Eoblattodea) † Squad Cockroaches (Dictyoptera) Order Termites (Isoptera) Superorder Heraridae (Heraridea) Order Heraridea (Heraridea) † Superorder Orthoptera (Heteroneura) Order Prothoptera (Proorthoptera) † Order Orthoptera (grasshoppers, crickets and locusts) Order Ghost (Phasmatodea) (stick insects) Order Titanoptera ( Titanoptera) † Subcohort Paraneoptera Order Caloneurida † Order Hypoperlida † Order Zoraptera (Zoraptera) Superorder Hay-eating (Panpsocoptera) Order Hay-eaters (Psocoptera) Order Fluffy (Phthiraptera) Order Thrips (Thysanoptera) Superorder Proboscis (Rhynchota) Order Heteroptera proboscis (Homoptera) Subcohort Insects with complete metamorphosis (Oligoneoptera) Superorder Myomopterous (Palaeomanteidea) Order Myomoptera (Miomoptera) † Superorder Reticulate (Neuropteroidea) Order Large-winged (Megaloptera) Order Camel (insect) (Raphidioptera) Order Jurinidae (Glosselytrodea) Order † Order Order Neuroptera (Neuroptera) Coleoptera (Coleoptera) (beetles) Order Fan-winged (Strepsiptera) Superorder Mecopteroides (Mecopteroidea) Order Scorpionfish (Mecoptera) Order Caddisflies (Trichoptera) Order Lepidoptera (butterflies) Order Diptera (Diptera) (flies and mosquitoes) Order Fleas (Aphaniptera) Superorder Hymenoptera (Phleboptera) Order Hymenoptera (bees, wasps, ants)

Origin

Establishing the origin of the class of insects is problematic. The key problem is the lack of fossils from which the phylogenetic relationships of insects could be established.

The latest morphological comparisons and phylogenetic reconstructions based on genomic sequences indicate that insects are descendants of crustaceans and not a sister taxon. This conclusion is in good agreement with paleontological data. However, morphological and molecular data are inconsistent in identifying the closest relatives of insects among crustaceans: morphological evidence indicates an association of insects with higher crustaceans, while molecular evidence indicates an association with branchiopods.

In accordance with the latter hypothesis, the evolutionary branch of insects separated from crustaceans in the late Silurian - early Devonian. This estimate is consistent with both paleontological data and the molecular clock estimate.

Insects in culture

Notes

Literature

M. Sokolov. Insects in culture and art // Sokolov M. N. Time and place. Renaissance art as the first line of virtual space. M.: 2002. S. 110-116.
Bei-Bienko G. Ya. General entomology. - M.: Higher school, 1980.
Gornostaev G. N. Insects. Encyclopedia of the nature of Russia. - M.: ABF, 1998. - 560 p.
Brullé G. A. Histoire naturelle des insectes. - Paris: 1834-1888, 1846.

Modern Arthropoda, subphyla and classes
Cheliceraceae (Chelicerata)	Arachnids Merostomata Pycnogonida
Millipedes (Myriapoda)	Chilopoda Diplopoda Pauropoda Symphyla
Six-legged (Hexapoda)	Insects(Insecta) Hidden jawed (Entognatha)
Crustaceans (Crustacea)	Branchiopods (Branchiopoda) Remipedia Cephalocarida Maxillopoda Shellfish (Ostracoda) Higher crayfish (Malacostraca)

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