Characteristics of the main orders of insects table. General characteristics of insect orders with complete metamorphosis. Day and night butterflies
Systematic position of the class, division into orders and families.
Insects are the highest invertebrates.
The class has more than 1 million species.
Habitat: soil, air-ground, organisms of other living beings
The body is divided into sections: head, chest, abdomen.
The thoracic region consists of three segments; each carries one pair of legs. Therefore, insects are characterized by the presence of 3 pairs of limbs. The second and third segments, in addition, can carry a pair of wings. In some insects, both pairs of wings are well developed, but wingless insects are also known. The abdomen consists of 6 - 12 segments. The type of complexly arranged oral apparatus of insects is determined by the method of feeding and can be gnawing (beetles), sucking (butterflies), piercing-sucking (lice), licking (flies).
body coverings and muscular system : have a chitinous cover, under which lies a single-layer hypodermal epithelium. The skin is rich in various glands: odorous, waxy, molting, etc. Muscles are striated.
Digestive system: mouth, pharynx, esophagus, goiter, stomach, midgut, hindgut ends with anus. There are salivary glands and a gland that performs the functions of the liver and pancreas. Digestion and absorption of food takes place in the midgut.
Respiratory organs: trachea.
excretory organs: Malpighian vessels and fat body.
Circulatory organs: the circulatory system is not closed, the tubular heart and aorta are located on the dorsal side. Due to the fact that there is an extensive network of tracheae, the circulatory system is poorly developed and lacks the function of an oxygen carrier. Hemolymph circulates through the vessels.
Nervous system: abdominal nerve chain with a strong tendency to concentrate ganglia in the head region, so the supraesophageal ganglion is transformed into a "brain" with three sections (anterior, middle, posterior). There are sense organs: eyes (faceted, but may be simple), balance, taste, touch and smell, in some - hearing.
Reproductive system: insects are dioecious, sexual dimorphism is often expressed. Gonads are paired (ovaries in females, testes in males). Sexual reproduction: with fertilization or parthenogenetic. Development is not direct: with complete metamorphosis (stages: egg - larva - pupa - imago) or incomplete metamorphosis (stages: egg - larva - imago).
The practical importance of insects is very great: pollinators of flowering plants, participate in soil formation processes, etc.
Among insects of medical importance, the following groups are distinguished:
The class Insects is divided into big number detachments.
Spreading: ubiquitous
Morphology: Its body is dorsally flattened and covered with highly extensible chitinous cover. The wings are completely reduced. Bedbugs attack a person at night, and spend the day in shelters - in furniture, behind wallpaper. The saliva of the bed bug contains a poisonous secret, so its bites are painful, the transfer of pathogens of any infectious diseases by the bed bug has not been proven.
Medical and epidemiological significance:
Locally with a bite: hyperemia, swelling, itching, blisters. Absorb for 1 time up to 7 ml of blood. Bed bugs living on birds and mammals can also attack a person - it is possible that viruses that cause psittacosis are transmitted. In tropical countries, bedbugs can transmit trypanosomes and a number of other pathogens.
Prevention: sanitization of dwellings.
Insect with complete transformation (with metamorphosis) goes through four stages in its development: egg - larva - pupa - adult insect (adult).
Pay attention!
Orders of insects with complete metamorphosis: butterflies (lepidoptera), beetles (coleoptera), diptera, hymenoptera, fleas.
Most insect species are characterized by development with complete transformation. In insects with complete metamorphosis (butterflies, beetles, flies, wasps, ants), the larvae do not look like adults at all. They lack compound eyes (there are only simple eyes, or organs of vision are completely absent), antennae are often absent, there are no wings; the body is most often worm-like (for example, butterfly caterpillars).
In insects with complete metamorphosis, the larvae often live in completely different places and feed on different food than adult insects. This eliminates competition between different stages the same types.
Insect larvae with complete transformation molt several times, grow and, having reached the limiting size, turn into chrysalis. The pupa is usually immobile. An adult insect emerges from the pupa.
Watch a video that demonstrates the release of the Monarch Butterfly from the chrysalis.
Order Butterflies, or Lepidoptera
Butterflies differ from other insects mainly in two ways: scaly cover of wings and sucking mouthparts coiled up.
Butterflies are called Lepidoptera because they have small chitinous cells on their wings. scales. They refract the incident light, creating a bizarre play of shades.
The coloration of butterflies' wings helps them to recognize each other, camouflages them in the grass and on the bark of trees, or warns enemies that the butterfly is inedible.
The mouthparts of butterflies sucking- this is a proboscis rolled into a spiral. Butterflies feed on the nectar of flowers.
Butterfly larvae (caterpillars) have a gnawing mouth apparatus, they feed on plant tissues (most often).
When pupating, the caterpillars of some butterflies secrete silk threads. The silk thread is secreted by a special silk-separating gland located on the lower lip of the caterpillar.
Detachment Beetles, or Coleoptera
Representatives of this group have dense hard elytra covering the second pair of leathery wings with which they fly. The oral apparatus is gnawing.
Among the beetles there are many herbivores, there are predators and scavengers.
Beetles live in the ground-air environment (on plants, the surface of the earth, in the soil) and in water.
Beetle larvae can be very mobile predators, living openly, and inactive, similar to worms, living in shelters and feeding on plants, fungi, and sometimes decaying remains of organisms.
Order Diptera
These insects have only one pair of wings. The second pair is greatly reduced and serves to stabilize the flight. This group includes mosquitoes and flies. They have piercing-sucking or licking mouthparts. Some dipterans feed on pollen and nectar of flowers (syrphid flies), there are predators (ktyrs) and bloodsuckers (mosquitoes, midges, midges, horseflies). Their larvae live in the decaying remains of cesspools, composts (house flies), in water (mosquitoes and midges) or lead a vagrant lifestyle and prey on small insects.
Order Hymenoptera
The group includes such well-known insects as bumblebees, wasps, bees, ants, sawflies, riders. They have two pairs of membranous wings (some do not have wings).
The insect class has two subclasses: primary wingless And winged.
TO subclass primary wingless include insects whose ancestors never had wings (sugar silverfish, springtails, etc.). Silverfish lives in sheds, closets. basements. It feeds on decaying substances, harmless to humans. IN flower pots with immoderate watering, wingless insects often appear - springtails. They feed on decayed plants or their lower plants. A reliable fight against them is a decrease in watering.
Subclass of winged subdivided into insects incomplete transformation and insects from complete transformation.
The distribution of species by orders is carried out taking into account such features as the nature of development, structural features of the wings, and the structure of the mouth apparatus. The main features of some orders of insects are presented below.
| Detachments | Type of development | Number of pairs of wings | oral apparatus | Feature of the development of the wings | Some representatives |
|---|---|---|---|---|---|
| cockroach | With incomplete transformation | Two pairs | gnawing | elytra | Red and black cockroaches |
| termites | With incomplete transformation | Two pairs | gnawing | Mesh | Termite |
| Orthoptera | With incomplete transformation | Two pairs | gnawing | elytra | Locusts, grasshoppers, crickets |
| Lice | With incomplete transformation | no wings | piercing-sucking | Wingless | Head louse, body louse |
| bedbugs | Louse | Two pairs | piercing-sucking | elytra | Bug-turtle, bug-gladun, bug-water strider |
| Homoptera | With incomplete transformation | Two pairs | piercing-sucking | Mesh | cicadas |
| grandmother | With incomplete transformation | Two pairs | gnawing | Mesh | Grandmother-dozorets, grandmother-rocker |
| Beetles, or Coleoptera | With complete transformation | Two pairs | gnawing | Elytra hard | Chafer, Colorado beetle, gravedigger beetles, bark beetles |
| Butterflies, or Lepidoptera | With complete transformation | Two pairs | Sucking | Mesh with scales | White cabbage, hawthorn, silkworm |
| Hymenoptera | With complete transformation | Two pairs | Gnawing, lacquering | Mesh | Bees, bumblebees, wasps, ants |
| Diptera | With complete transformation | 1 pair | prickly-sucking | Mesh | Mosquitoes, flies, gadflies, midges |
| Fleas | With complete transformation | No | prickly-sucking | Wingless | Human flea, rat flea |
Insects with incomplete metamorphosis
The most common are: cockroach squad- a typical representative - red cockroach. The appearance of cockroaches in dwellings is a sign of carelessness. They come out of their hiding places at night and feed on carelessly stored food, polluting it. Female cockroaches at the end of the abdomen wear a brown egg "suitcase" - ooteku. They throw it in the trash. Eggs develop in it, from which larvae are born - small white cockroaches that look like adults. Then the cockroaches turn black, molt several times and gradually turn into adult cockroaches.
Order of termites- this includes social insects living in large families in which there is a division of labor: workers, soldiers, males and females (queens). Termite nests - termite mounds, can be of considerable size. So, in the African savannas, the height of termite mounds reaches 10-12 m, and the diameter of their underground part is 60 m. Termites feed mainly on wood, they can damage wooden buildings, agricultural plants. About 2,500 species of termites are known.
Order Orthoptera Most members of the order are herbivorous, but there are also predators. These include grasshoppers, cabbage, locust. The green grasshopper lives in the grass in the meadows, in the steppes. It has a long club-shaped ovipositor. Kapustyanka - has burrowing legs, flies and swims well. It causes great harm to the underground parts of garden plants, such as cucumbers, carrots, cabbage, potatoes, etc. Some species of locust are prone to mass reproduction, then they gather in huge flocks and fly a considerable distance (up to several thousand kilometers), destroying all green vegetation on your way.
Detachment of bedbugs- this includes known pests of agricultural crops - bug-turtle, sucking out the contents of the grains of cereal plants. Found in dwellings flea bug- a very unpleasant insect for humans. A water strider bug lives in fresh water bodies or on their surface, feeding on insects falling into the water. Predatory bed bug attacks various invertebrates and fish fry.
Detachment Homoptera- all its representatives feed on plant juices. many kinds aphids cause great harm to cultivated plants. Many Homoptera are carriers viral diseases plants. This includes various cicadas, whose sizes are from a few millimeters to 5-6 cm. They live in the crowns of trees.
Granny Squad- exclusive predatory insects. Adults attack prey in flight. The best flyers. Their flight is highly maneuverable: they can hover in the air, be mobile and can reach speeds of up to 100 km per hour. These include headstock-yoke, grandmother watcher and etc.
Insects with full metamorphosis
Squad beetles, or Coleoptera, is the most numerous order of insects, up to 300,000 species. Beetles are distributed in a wide variety of conditions on land and fresh water. Their sizes range from 0.3 to 155 mm in length. Many beetles cause great damage to cultivated plants. One of the pests of potatoes and other plants is Colorado beetle brought to us from America. beetle- a pest of cereals; Chafer- its larvae damage tree roots and potato tubers; beet weevil- affects sugar beets. In addition, this includes bark beetles, turning passages in the bark and bast fibers of valuable tree species, and the larvae goldfish and i live in dead wood, causing great damage to timber industry.
Many beetles spoil food supplies: pea weevil, beetle grindstone, leather beetle damaging leather, wool products. Another small beetle belongs to the order of beetles tube-roller. The biology of these beetles is very interesting. IN springtime The pipe driver cuts the sheet to the main vein in a special way. The incised part of the leaf withers and loses its elasticity. Then the beetle rolls up the bag and lays eggs there. Something like a cigar is formed. This is how a pipe worker expresses concern for offspring.
Some beetles feed on the remains of plants and animals and perform the role of orderlies in nature, for example: gnoe beetles And coffins. Some can be used to fight harmful insects. So, ladybug destroys aphids, and large green paint beetles- caterpillars.
Beetles are extremely beautiful large sizes, For example stag beetle, or stag, listed in the Red Book, reaches a length of up to 8 cm, its larvae develop in rotten stumps for about five years and grow up to 14 cm long. Beetles of various sizes and in the way of feeding live in reservoirs - a swimming beetle, and a black water lover. The swimming beetle is a predator, the black water-lover is a herbivore.
Butterfly Squad, or Lepidoptera, - representatives of this detachment are distinguished by a variety of colors of their wings. These include hives, cabbage butterfly, silkworm and others. Among the species living on Far East, there are very large night butterflies, which in the wingspan correspond to the width of an unfolded notebook. Butterfly wings are covered with modified hairs - scales that have the ability to refract light. The iridescent color of the wings of many butterflies depends on this phenomenon. Butterfly larvae are called caterpillars. They have a gnawing apparatus, a long body. Their salivary glands, in addition to saliva, also secrete silk threads, from which a cocoon is woven before pupation. Adult butterflies are very good plant pollinators. The caterpillars of most butterflies are herbivorous, eating the leaves of plants, causing significant harm, for example, cabbage white, apple moth, golden tail, ringed silkworm, etc. The room moth caterpillar feeds on woolen products, damaging them, some caterpillars spoil flour and others food products.
Mulberry and oak silkworms- they have been bred for a long time by a person in order to obtain silk (from cocoons). Many large butterflies are extraordinarily beautiful, for example swallowtail, Apollo etc. A large butterfly is very interesting nocturnal peacock eye, on the wings of which there are eye spots. Its caterpillar is large, fleshy, green in color, weaves a cocoon the size of a chicken egg before pupation.
Large night butterflies with acute-angled wings, characterized by very fast flight - hawk moths, - so named because they willingly feed on the fermented and odorous sap of trees, especially birch, acting on wounds and stumps.
Order Hymenoptera- combines a variety of insects: bees, bumblebees, os, riders, sawflies and others. The way of life of these insects is varied. Some of them are herbivorous, as their larvae (very similar to caterpillars) cause great damage to cereals and other plants, for example bread and pine sawflies. The leaf-eating larvae of the sawfly acquire similarities with butterfly caterpillars to such an extent that they are called false caterpillars. A striking adaptation is the sawfly ovipositor, which serves to cut out pockets in plant tissues, in which female sawflies hide their eggs, thereby showing original care for their offspring.
Excellent plant pollinators are bumblebees. This is a social insect. The family of bumblebees exists only for one summer. Nests are built in mouse holes, hollows, squirrel nests, in birdhouses. The nest is built by the female, equipping wax cells in it for laying eggs. A supply of food is placed in the cell - a mixture of pollen with honey. The larvae that emerge from the egg eat food and, after two or three weeks, weave silk cocoons, turning into pupae. Working bumblebees, females and males are hatched from pupae. By the end of summer, there are up to 500 bumblebees in large nests. In autumn, the old queen, males and workers die, and the young queens hide for the winter.
Lifestyle os looks like a bumblebee. They also exist for one summer. Wasps are beneficial by destroying harmful insects, and the damage from spoiling fruits by them is small. More damage from hornets(one of the types of swarm wasps): they gnaw at the bark of young trees and eat bees. Having settled near the apiary, they destroy thousands of bees over the summer.
Of the social insects of the order Hymenoptera great benefit brings honey bee. She is also a wonderful pollinator of plants, and produces exclusively useful product food - honey, as well as wax, royal jelly, widely used by man in perfumery. medicine, for the manufacture of varnishes, paints, etc.
The bee colony is an amazingly complex whole in which all members of the colony are very closely related to each other. The life and prosperity of the whole genus is equally impossible without a queen and without drones, without worker bees. Using knowledge about the life of all members bee family, beekeepers have learned to create specialized houses for bees - hives, conditions for feeding bees (taken to those fields where honey plants are grown) and receive not only honey good quality but also the quantity.
Representatives of the order Hymenoptera are used as biological method pest control. These include various riders, as well as a trichogram, which is derived artificially
Order Diptera. These include all known insects: flies, mosquitoes, midges, gadflies, horseflies and other insects similar to them, possessing one pair of transparent wings. The second pair of wings turned into the so-called halteres. The common mosquito lives in marshy and damp areas. Mosquitoes are especially numerous in the middle of summer. The inhabitants of the taiga and tundra call them clusters vile. With their piercing mouthparts, mosquitoes easily pierce human skin and suck his blood. Worm-like larvae of mosquitoes live in stagnant water. Feeding, the larvae grow, molt and turn into mobile pupae. Mosquito pupae also live in water, they cannot eat, so they soon turn into an adult.
Malarial and common mosquitoes are distinguished by landing.
Common mosquito (peeper) keeps his body parallel to the surface on which he sits, and malarial- at an angle to it, raising the rear end of the body high. The malarial mosquito lays its eggs one by one in a pond, the common one - in packs floating on the surface in the form of rafts. Mushroom mosquito larvae live in the fruit bodies of cap mushrooms.
flies unlike mosquitoes. have short antennae. Their larvae are white, usually legless and headless. At house fly worm-like larvae live and develop in kitchen waste, in heaps of manure and sewage, where the fly lays its eggs. Before pupation, the larvae crawl out of the sewage, penetrate the soil and turn into pupae.
Adult flies hatched from pupae fly everywhere in search of food. From latrines and cesspools, they fly to openly lying food and contaminate them. Flies transfer bacteria to human food gastrointestinal diseases and roundworm eggs. Therefore, it is very important to fight flies. Food products are protected from flies with gauze or caps, vegetables and fruits are washed before use.
Midges- long-whiskered bloodsuckers small size, whose larvae develop at the bottom of water bodies with running water. In the tropics and subtropics, in the Crimea, very small mosquitoes are found - mosquitoes. Their larvae develop in moist soils, rodent burrows, etc. Mosquitoes are carriers of many diseases (malaria, etc.). We have a "Hessian fly" that destroys cereal plants.
Gadflies, horseflies cause great harm to humans and domestic animals with their bites, as well as the ability to carry pathogens of such dangerous diseases as tularemia, anthrax.
However, flies are pollinators of many plants.
rat flea can transmit plague pathogens from sick rodents - a very dangerous disease that once claimed thousands of human lives.
Habitat, structure, lifestyle
Insects are the largest class of animals. It includes over 1 million species. Insects live everywhere: in forests, gardens, meadows, fields, orchards, on livestock farms, in human dwellings. They can be found in ponds and lakes, on the body of animals.
The body of insects consists of a head, thorax and abdomen. There are a couple on the head compound eyes, a pair of antennae, on the chest - three pairs of legs, and most have one or two pairs of wings, on the sides of the abdomen - spiracles.
Insects differ in the shape of the body parts, the size of the eyes, the length and shape of the antennae, and other features. Their antennae, mouth organs, and legs are especially diverse. Some of the insects have lamellar antennae (many beetles), others are filiform (grasshoppers), others are pinnate or club-shaped (butterflies), etc. like butterflies, etc. The hind legs of grasshoppers are jumping, those of swimming beetles are swimming; The front legs of the bear are digging. All these and other structural features have developed in insects in connection with adaptation to certain living conditions.
Rice. Bombardier (beetle). Family - ground beetles
Peculiarities internal structure insects are associated mainly with the respiratory, excretory and nervous systems. The respiratory organs of insects - the trachea - are highly branched. In small insects, gas exchange occurs by diffusion. large insects ventilate the trachea (when the abdominal walls relax, air is sucked into the trachea, and when it contracts, it exits into external environment). The excretory organs of insects are numerous tubules, the free ends of which are closed. The excretory products that enter them drain into the posterior intestine. Insects have fat cells with a supply of nutrients and water. They also deposit some substances that are unnecessary for the body.
Differences in the nervous system of insects are associated with enlargement of the supraesophageal ganglion (it is often called the brain), a decrease in the number and enlargement of the nodes of the abdominal nerve chain. A more complex structure of the nervous system is manifested in the complexity of the behavior of insects. A bee, for example, having found flowering nectar-bearing plants, upon returning to the hive, crawls on the combs, "dances", describing certain figures, according to which other bees set the direction to the place of honey collection. Ants close the entrances to the anthill at night, bring wet needles to the surface, and after drying they drag them deep into the anthill.
Types of insect development
Insects are dioecious animals. In some insects (locusts, bugs), from fertilized eggs laid by females, larvae develop that look like adults. Eating intensely, they grow, molt several times and become adult insects. In other insects (butterflies, beetles, flies), the larvae are not similar in appearance and nutrition to adults. The larvae of the cabbage butterfly, for example, are worm-like and feed not on nectar, like butterflies, but on cabbage leaves. Their oral apparatus is not sucking, but gnawing. After a few molts, the caterpillars turn into pupae that do not feed and do not move, but complex changes occur under their chitinous cover. After some time, the cover of the body of the pupa bursts and an adult insect emerges from it.
Development that occurs in three phases, and insect larvae at the same time look like adults, is called incomplete transformation. The development of insects, which proceeds in four phases (including the pupal phase), and the larvae do not look like adults, is called complete transformation.
Development with transformation enables insects to survive under adverse living conditions ( low temperature, lack of food) at one or another less vulnerable stage of development. Insects with complete transformation have the greatest advantages. Their larvae do not compete with adults: they usually use different food and develop in other habitats.
Major orders of insects
In the class of insects, from 30 to 40 orders are distinguished. The largest of them are the orders of Orthoptera, Homoptera, Hemiptera, Coleoptera, Lepidoptera, Hymenoptera, Diptera.
Squads of insects with incomplete metamorphosis. The Orthoptera order includes locusts, grasshoppers, crickets, and bears. They are characterized by gnawing mouthparts, two pairs of longitudinally veined wings, and a (usually) hopping hind pair of legs. Many orthopterans make and perceive sounds (in grasshoppers, the sound apparatus is located on the front wings, and the auditory apparatus is on the shins of the front legs). Their antennae are filiform. The females of many species have an ovipositor. The order Homoptera includes aphids, cicadas, etc., feeding on plant sap, having a piercing-sucking proboscis and 2 pairs of transparent wings.
The order Hemiptera, or bugs, includes terrestrial and aquatic insects with piercing-sucking mouthparts, two pairs of wings (semi-rigid upper and membranous lower), highly developed odorous glands. Of the representatives of this order, the most common are green forest bugs, long-legged water strider bugs. belongs to the same group bed bug, feeding on the blood of people and animals living in human housing.
Squads of insects with complete metamorphosis. The order Coleoptera, or beetles, includes insects with rigid anterior wings and membranous hind wings. In most beetles at rest, the rigid wings completely cover the membranous and protect them from damage. The mouthparts of beetles are gnawing. The Coleoptera order includes May beetles, ground beetles, ladybugs, weevils.
Butterfly Papilio demoleus. Photo: Jeevan Jose
For the vast majority of insects of the order Lepidoptera, or butterflies, two features are characteristic: a scaly cover on two pairs of wings and a sucking mouth apparatus, usually coiled. The antennae of diurnal butterflies are usually club-shaped, those of nocturnal butterflies are feathery. Worm-like butterfly larvae (caterpillars), in addition to three pairs of jointed legs, have false legs - outgrowths of the body. Caterpillars have chewing mouthparts.
Diptera - flies, mosquitoes, horseflies, etc. - have one pair of membranous wings. The hind wings are transformed into flask-shaped organs - halteres. Mouthparts of Diptera are piercing-sucking or licking. The larvae do not have legs. They develop in water, soil, in the decaying remains of plants, live animals and corpses.
Insects are the most numerous class of animals, there are more than 1 million species. There are about 40 orders of insects, which are divided into two groups - insects with incomplete transformation and insects with complete transformation.
Examples of insect orders with incomplete metamorphosis are orthoptera, homoptera, and hemiptera. Examples of orders with complete metamorphosis are Coleoptera, Diptera, Lepidoptera, Hymenoptera.
Features of the order Orthoptera
Representatives: grasshoppers, locusts, crickets.
- Gnawing mouth apparatus.
- The wings of the first pair are narrow with longitudinal venation, the wings of the second pair are fan-shaped.
- Hind legs jumping type (not all).
- Many can make sounds and perceive them (grasshoppers make sounds with their front wings, and the hearing organ is on their feet).
Features of the order Homoptera
Representatives: aphids, suckers, shield insects.
Aphids live on the shoots of trees, shrubs and grasses, forming clusters. There are usually a lot of suckers on the leaves of fruit trees.
- They feed on plant sap.
- A piercing-sucking mouthpart with a proboscis.
- Two pairs of soft transparent wings (not all).
Features of the order Hemiptera (bugs)
Representatives: green forest bugs, water strider bugs, bed bugs.
- They lead a terrestrial or aquatic lifestyle.
- Piercing-sucking mouthparts.
- A pair of semi-rigid upper wings and a pair of membranous lower wings.
- Developed odorous glands.
Features of the order Coleoptera (beetles)
Representatives: ladybugs, weevils, dung beetles, ground beetles, May beetles.
- Rigid forewings protect the hind wings from damage.
- Mouth apparatus gnawing type.
Features of the order Diptera
Representatives: flies, mosquitoes.
- One pair of membranous wings. The hind ones are modified into halteres.
- Mouth-apparatus piercing-sucking or licking.
Characteristics of the insect squad
- Legless larvae that develop in soil, water, plant and animal remains.
Features of the order Lepidoptera (butterflies)
- Scale cover of wings.
- The sucking mouthparts are coiled.
- Cirrus (in nocturnal) or club-shaped (in diurnal butterflies) antennae.
- Butterfly larvae are caterpillars.
They have outgrowths of the body - false legs. Mouth apparatus gnawing type.
Features of the order Hymenoptera
Representatives: bees, wasps, ants, riders.
- Two pairs of membranous transparent wings.
- Mouth apparatus gnawing or licking.
- Females have an ovipositor at the end of the abdomen, which in some species is turned into a sting and is associated with venom glands.
- Worm-like, most often legless, larvae.
Detachment Coleoptera, or beetles
The front wings, or elytra, are very rigid and strong.
They cover the upper side of the abdomen and the membranous wings of the second pair located here. It is these membranous wings that are used for flight.
They are slightly longer than the elytra and are folded and hidden under them when at rest.
The mouth organs of beetles are of the gnawing type. The main tools for crushing food are the upper jaws, often called mandibles, or mandibles. Sometimes they turn into ornaments, reaching extraordinary development in males ( bug—deer).
The elytra and wings of beetles are attached to the mesothorax and metathorax. The prothorax forms a wide ring, the upper part of which is called the pronotum.
From below, three pairs of legs are attached to the three thoracic segments, which are extremely diverse in beetles. Usually they are long, running, in aquatic forms - swimming, in those living in the soil - digging; sometimes the hind legs increase in size, their thighs thicken - the legs become jumpy. The legs end with paws, the segments of which carry pads from below, and in some species - suckers.
Beetles are fully metamorphosed insects that lay eggs after mating.
The larvae emerge from the eggs, the body of which consists of 3 thoracic and 10 abdominal segments. The development of larvae is completed in a few months, rarely stretches for three to five years. Further, the larva turns into a pupa, and from a pupa into an adult insect.
This order includes beetles that damage a wide variety of cultivated plants ( Chafer, bread beetle, clickers, whose larvae are called wireworms, Colorado beetle, apple beetle), forest plants ( beetles—bark beetles, beetles—lumberjacks,); beetles destroy food barn weevil, bread fleas).
Predatory bugs destroy pests Agriculture (ground beetles, ladybugs), beetles that eat animal excrement and dead parts of plants are of great sanitary importance ( beetles—dung beetles) and animal carcasses ( beetles—dead eaters). Some beetles have moved to life in fresh water ( beetles—swimmers, beetles—water lovers).
Over 30 thousand species.
Lepidoptera order, or butterflies
Of all insects, butterflies are the most famous. The most important feature of the detachment is that they are covered with scales, the structure and location of which determine the quirkiness and variety of colors. Therefore, butterflies are called Lepidoptera.
Insects. Troops Dragonflies, Mayflies
Scales are modified hairs. Along the edge of the wing are very narrow scales, almost like hairs. Closer to the middle they are expanded, but their ends are sharp. And even closer to the base of the wing, wide scales sit in the form of a flattened, hollow pouch attached to the wing by means of a short stalk.
The scales are arranged on the wing in regular rows across the wing: the edges of the scales face the lateral edge of the wing, and their bases are covered in a tiled manner by the ends of the previous row.
Usually, all four wings are developed in Lepidoptera; however, in females of some species, wings may be underdeveloped or absent altogether.
The forewings are always larger than the hindwings. In many species, both pairs of wings interlock with each other using a special hook, or “bridle”.
The mouthparts are sucking. They are represented by a soft proboscis that can coil and unfold like a clock spring. The basis of this oral apparatus is made up of strongly elongated inner lobes of the lower jaws, which form the flaps of the proboscis. The proboscis is elastic and mobile.
Lepidoptera are insects with complete metamorphosis.
Their larvae are very diverse in shape. Butterfly larvae are called caterpillars, their body consists of a head, 3 thoracic and 10 abdominal rings. They use a silky thread to build a cocoon, inside which pupation takes place.
And only after a few weeks the butterflies fly out.
This group includes silkworm, leaf rollers, glassware, moth, scoops, pigeons, cabbage, moths, hawk moths and others. About 140 thousand species.
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All about insects
Insect - what does this name mean? It says that his torso is divided into parts. Insecta is a Latin word that literally means "divided, dissected." Russian word"Insects" is also explained by the fact that the wasp's body is divided into three segments (parts of the body) - notches.
Class Insects, their orders, main features and significance (Table)
Ancient Greek word entomon similar value"divided", preserved in the name of the science of insects - entomology. The scientific name of species is based on the principle of binary nomenclature: genus name + species name. For example, the name of the honey bee is made up of the name of the genus Apis and the name of the species mellifera. Thus, scientific name honey bees - Apis mellifera.
In the tropics there are many species of insects, but in Europe there are currently at least 30,000 species.
In order to somehow understand this diversity, biologists 200 years ago began to systematize knowledge about animals, based on their typical features. Similar to each other and capable of reproduction, they attributed to the same species. Species that had a common ancestor and are thus related were grouped into genera.
Many genera form a family, several families - a detachment, several orders - a class, classes are combined into types, which, in turn, belong to the animal kingdom. Thus, each species gets its own place in the natural system.
In 2002, scientists discovered an unknown insect in the rocky canyons of Namibia. It looked like a cross between a praying mantis, an Annam stick insect, and a grasshopper. Shortly before this, similar insects were discovered in amber that had solidified 45 million years ago; they were classified as extinct species.
Squads of insects
At present, the class of insects is subdivided into more than 30 orders.
At the same time, the orders of cockroaches, zorapters and large-winged ones include less than a hundred species, hymenoptera, butterflies and beetles - more than a hundred thousand species. The first two orders are not found in Europe. Representatives of other, less well-known detachments, although they are found in our area, live secretly, and their size is so small that in order to see them, you need a microscope.
The insects presented here can be found during a normal walk in the field and forest.
Fly - mayfly
Mayflies die a few hours after birth; the maximum life span of a fly is a few days.
Adult mayflies do not feed. Their only task now is to find a partner and lay eggs. As larvae, mayflies spend from one to three years at the bottom of streams, rivers and lakes. All this time they feed on algae, parts of plants and small invertebrates (crustaceans).
beetles
Coleoptera are the largest order of insects, with over 300,000 species.
They have mastered all areas of habitat - from land to fresh water. Among them there are herbivores and predators, some feed on manure and carrion. In beetles, the rigid forewings (elytra) cover the flying hindwings. Usually, before taking off, the beetles raise their rigid elytra and spread their hindwings.
Common silverfish and forktails
In many orders of insects, there are wingless species that have lost wings in the process of evolution.
These are, in particular, forktails and silverfish. Forktails are no more than 1-2 millimeters long, live in the ground, where they feed on rotting plant and animal remains. These insects owe their name to a special jumping fork on the underside of the abdomen. If they are disturbed, they can jump far in an attempt to protect themselves.
The most famous representative of silverfish is the common silverfish, Lepisma saccharina, which can sometimes be found in our kitchens and bathrooms.
Locusts and Grasshoppers
Locusts and grasshoppers need strong hind legs in order to quickly hide from the enemy.
When locusts use their wings, they are able to cover noticeable distances with lightning speed. By their long hind legs, powerful body, strong head and leathery wings, locusts and cicadas are easy to distinguish from other insects.
The Italian locust feeds almost exclusively on plants; true grasshoppers and crickets are omnivores. For them, animal food (insects and their larvae) can make up more than half of the diet.
Characteristics of insect orders with various variations of sucking mouth organs.
Order Diptera (diptera) The external appearance of Diptera is characteristic, primarily due to the reduction of the hind wings, which are turned into short halteres.
However, these are not useless rudiments. Covered with a large number of sensitive receptors, the halteres stimulate the nervous system and ensure the rapid activation of the forewings and the launch of Diptera, while simultaneously being flight stabilizers.
Diptera usually have a large, often spherical head with large eyes, which in males may touch on the forehead.
The most common orders of insects
Antennae are of two types - multi-segmented in the suborder of long-whiskered dipterans and three-segmented in the suborder of short-whiskered dipterans. Mouth organs are transformed into various proboscis. Those who eat liquid organic matter these are sucking or licking-sucking organs, in bloodsuckers - piercing-sucking.
In connection with the diptera, the mesothorax is especially developed.
Noticeable costalization of the wing is observed; thickening of the anterior veins and shifting them to the anterior margin. The flight of Diptera is very perfect, especially in Hoverflies, with quick start and hovering in the air.
Mosquitoes can make up to 1000 wing beats per second, although they fly relatively slowly.
Diptera larvae are legless and rarely have false ventral limbs. In long-whiskers with a separate head, however, in most fly larvae, the head capsule is reduced, and the oral appendages are represented by a pair of retractable hooks. Pupae are free, or in a false cocoon - puparia. When the fly emerges from the puparium, its shell at the top is either torn longitudinally (in straight-sutured dipterans) or in a circle, and folds back in the form of a small lid (in round-sutural dipterans).
Order Hymenoptera (Hymenoptera). This order includes both rather primitive sawflies, whose caterpillars, similar to butterfly caterpillars, feed on plants, and insects with the most highly organized nervous system and extremely complex biology - ants, bees and wasps.
Adult insects have two pairs of membranous wings covered with relatively sparse veins, and small forms are usually almost or completely devoid of venation. The hind pair of wings is smaller and is of secondary importance in flight.
In living insects, both pairs of wings are usually fastened with hooks to each other and work as a single plane. The mouthparts are gnawing or licking-gnawing. IN last case the lower lip and lower jaws are extended and form a proboscis with a tongue at the end.
Such a mouth apparatus serves to suck nectar from flowers. Mandibles are well developed in all species and are used not only for feeding, but also for building nests, digging soil, etc.
d. Antennae are simple, club-shaped, comb-shaped, pinnate, are both straight and geniculate. The tibia and tarsus of the fore leg sometimes bear a special apparatus for cleaning the antennae and tarsi, formed by a pectinate spur at the end of the tibia and a notch on the first segment of the tarsus.
Lepidoptera, or butterflies (Lepidoptera) differ from other orders of insects in such features as sucking mouth organs that look like a thin, coagulating proboscis, a colored scaly cover of the wings, as well as development with complete transformation, i.e.
the presence in their development of a caterpillar, which is a worm-like larva, and a pupae.
The smallest scales located on the wings of butterflies served as the basis for assigning the name to the detachment of these insects - "Lepidoptera", since they are their main distinguishing feature.
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1. What are the features external structure and internal organization of insects?
Insects are the most diverse class of arthropods. Despite the large number of species, there are some common features external building:
The body consists of three sections: head, chest and abdomen; covered with chitinous cover;
There is one pair of antennae on the head; all head segments fused;
The chest always consists of three segments: anterior, middle, and metathorax;
Three pairs of walking legs (attached respectively to each segment of the chest);
Compound eyes (faceted) located on the sides of the head;
Most have wings (on the second and third segments of the thoracic region);
The abdomen is segmented; the number of segments varies between species.
2. How many sections does the body of insects consist of?
The structure of insects. The body of adult insects, like all arthropods, is covered with a chitinous cover that acts as an external skeleton, and is divided into a head, chest and abdomen, which distinguishes them from other arthropods. The segments of the head are fused into a common mass, the segments of the thorax and abdomen are more or less clearly distinguishable. The head and chest bear limbs, the abdomen sometimes retains only underdeveloped limbs, i.e., their rudiments.
3. How are the limbs of insects arranged?
The limbs of insects are a system of levers movably connected to each other with a large number of degrees of freedom, that is, capable of varied and precise movements. Most of all, the running legs (beetles, cockroaches), the most common among insects, correspond to the type described. In animals capable of jumping, such as grasshoppers, the femur and tibia of the hind pair of legs are strongly extended. In burrowing insects - the bear - all legs, and especially the front ones, are shortened, become massive and acquire powerful weapons from chitinous teeth. The swimming limbs are flattened in the form of an oar and are equipped with a dense row of elastic rowing hairs (beetles).
4. What kind of wings do insects have? What is the physical basis of insect flight?
A characteristic feature of many insects is the ability to fly. The wings, one or two pairs, are located on the second (mesothorax) and third (mesothorax) thoracic segments and represent folds of the body wall. The wing has the appearance of a thin plate, it is two-layered.
In different orders of insects, the forewings and hindwings may be developed differently. Beetles are characterized by the transformation of the front wings into thick and hard elytra, which almost do not participate in flight and mainly protect the dorsal side of the body. Only the hind wings are real, which are hidden under the elytra at rest.
5. Make a table "Squads of insects", indicating for each squad a representative, type of mouth apparatus, number of wings and type of development (work in small groups).
6. Why do you think the circulatory system of insects is not involved in the transport of gases throughout the body?
Because in insects, the respiratory organs are tracheas, which, like a circulatory system, deliver oxygen to all organs and tissues.
7. Make a detailed outline of the paragraph.
general characteristics class Insects;
Features of the external structure of representatives of the class Insects;
The structure of the wings;
Muscular system;
Nervous system of insects;
Sense organs of insects;
The structure of the circulatory system;
Respiratory Organs Insects;
Digestive system;
excretory organs;
Reproduction and development of insects;
Variety of Insects;
The value of insects in nature and for humans.
