Class Insects- this is the most highly organized, numerous, diverse class of arthropods, distributed in all environments of life, and secondarily in aquatic environments. Most representatives are capable of flight. Insects belong to the phylum Arthropods.
Meaning of insects:
1. Participation in the cycle of substances
2. Important role in food chains
3. Flower pollination and seed dispersal
4. Obtaining food, medicines, silk
5. Pests agriculture
6. Predatory insects exterminate agricultural pests
7. Damage to fabrics, wood, books, mechanisms
Class Insects
Body parts
Head, chest, abdomen
Structural features
There are wings
Habitat
In all environments
Number of walking legs
Different species have different foods and different mouthparts
Respiratory system
Tracheal bundles opening on abdominal segments
Circulatory system
OPEN; blood vessels open into the body cavity, on the lower side of the body blood collects in other vessels; there is a heart (two chambers - one atrium and one ventricle)
Excretory system
Malpighian vessels and fat body
Nervous system
Peripharyngeal nerve ring and ventral nerve cord
In insects, the brain is the result of the fusion of clusters nerve cells(therefore more complex behavior)
Sense organs
Vision (mosaic), smell, touch, hearing
Representatives
Orders Coleoptera, Scale-wing, Diptera, Hymenoptera, Orectoptera
The main orders of insects
|
Representatives |
Oral apparatus |
Transformation type |
||
|
Rigid-winged |
Zhuzhe-faces, May Khrushchev, lady cow |
The upper ones are hard (elytra), the lower ones are flying ones. |
Gnawing type; there are carnivores and plant-eaters |
↓ Larva (worm with three pairs of legs - caterpillar) pupa (resting stage) Adult |
|
Scale-wings |
Swallowtail, pigeon, nettle |
Two pairs, covered with scales |
Sucking type (hobo-current); feed on plant nectar; larvae (caterpillars) have gnawing mouthparts |
|
|
Two-winged |
Flies, mosquitoes, gadflies, horseflies |
One pair; the second pair of wings is modified into halteres |
Piercing-sucking type; feed on the blood of humans and animals |
|
|
Hymenoptera |
Bees, wasps, ants |
Two pairs, with clearly defined veins |
Gnawing or licking mouthparts, feed on nectar and pollen of flowers |
|
|
Straight-winged |
Saran-cha, blacksmiths, bear-ka |
Front - with longitudinal veining, rear - fan-shaped |
Gnawing mouthparts (feed on plant matter) |
INCOMPLETE (larva similar to adult; growth during molt) |
|
Bugs (hemiptera) |
Forest bug, berry bug, bed bug |
Two pairs of wings |
Piercing-sucking mouthparts |
|
|
Homoptera |
Aphids |
Two pairs of transparent wings |
oral organs - piercing-sucking proboscis |
Insects with incomplete metamorphosis
|
Lice, about 150 |
Human louse (head and body louse) |
|
|
Bedbugs, more than 30,000 |
2 pairs of wings (front - half-elytra, rear - membranous) are folded flat at rest on the back. Mouthparts - piercing-sucking |
Bedbug, water strider, harmful turtle |
|
Orthoptera, more than 20,000 |
2 pairs of wings (front ones - elytra with straight veins, rear ones - fan-like membranous wings). The mouthparts are gnawing. The hind legs are usually hopping |
Common grasshopper, house cricket, locust |
|
Dragonflies, about 4500 |
2 pairs of mesh wings. The body is usually elongated. The head is mobile, the eyes are very large. Mouthparts - gnawing |
Rocker, lute, beauty |
|
Cockroaches, 2500 |
2 pairs of wings (front - leathery elytra, rear - fan membranous). The mouthparts are gnawing. Eggs are laid in a shell |
Black cockroach, red cockroach, or Prussian |
_______________
Source of information: Biology in tables and diagrams./ Edition 2, - St. Petersburg: 2004.
96. Class Insects: general characteristics, taxonomy, medical significance. Epidemiological classification of insects with examples.
Phylum Arthropoda Arthropoda. Subphylum Tracheate Tracheata Class Insects Insecta
This is the most numerous class of animals in terms of the number of species. Their total number reaches 1 million.
The body of insects is divided into 3 sections: head, thorax and abdomen. The head segments (there are 5 of them) bear 4 pairs of limbs: the 1st pair – the ears (antennae), the 2nd and 3rd pairs – the jaws (the lower ones carry sensitive palps), the 4th – the lower lip (fused lower jaws).
Insects, depending on their lifestyle and method of feeding, can have different types of mouthparts: gnawing, piercing-sucking, licking, etc. There is 1 pair of simple or compound eyes on the head.
Insects are six-legged animals in which cuticular folds – wings – develop on their thoracic segments. Each chest segment corresponds to a pair of walking legs, which consist of 5 segments. The abdominal segments do not bear limbs, with the exception of those modified into copulatory appendages (cerci, styli).
Insects have very complex muscles that enable very fast movements. Chitin bears appendages - hairs, glandular bristles, odorous and poisonous glands.
Of the features internal structure It should be noted the more progressive structure of the central nervous system: the fusion of the cephalic ganglia into the brain, consisting of 3 sections: two hemispheres, optic lobes and mushroom bodies.
A feature of the digestive system is the presence of salivary glands.
The excretory system is the Malpighian vessels, which flow into the hind intestine.
Respiratory organs - trachea.
The circulatory system is poorly developed and not closed. Blood - hemolymph - does not carry formed elements, but performs only a trophic function.
The development of insects occurs with metamorphosis. In some, the metamorphosis is complete, with the replacement of larval organs at the pupal stage with organs of the imago; in others, it is incomplete (the larva is similar to the adult, and the pupal stage is missing).
Epidemiological classification
I Household insects
Temporary.
Order Bugs heliptera
Bedbug Cimex lectularius - it is known that the causative agents of many vector-borne diseases can remain viable in the body of bedbugs for a long time: typhus rickettsia and relapsing spirochetes, visceral leishmaniasis and plague. However, there is no evidence of the role of bedbugs in transmitting these infections.
Order Fleas Aphaniptera
The human flea Pulex irritans is a carrier of plague pathogens
Permanent.
Lice order Anoplura
Body louse Pediculus vestimenti - carries pathogens of relapsing and typhus
Pubic louse Phthirus pubis – causes pediculosis
2.Mechanical carriers
Order Cockroaches Blattoidea
Black cockroach Blatta orientales
The red cockroach Blattella germanica - carries pathogens of gastrointestinal infections, viruses, bacteria, diphtheria, protozoan cysts, helminth eggs, etc.
The housefly Musca domestica is more dangerous than cockroaches, like fur. carrier,
II Pathogens
Wohlfahrtia magnifica - the larvae cause myiasis in mammals, mainly sheep, but also in cattle, goats, horses and rarely in humans.
Order Diptera Diptera
Family Culicidae mosquitoes - transmit pathogens of encephalitis and tularemia, malaria
Family Phlebotomidae Mosquitoes - carry different types of Leishmania, pappataci fever viruses
The horsefly family Tabanidae - in northern latitudes they are carriers of the pathogens of anthrax and tularemia, and in the tropics - the pathogens of loiasis.
Midge family Simuliidae - transmits onchocerciasis pathogens
The midling midge family Ceratopogonidae carries the causative agents of some filariatrosis.
Description of the presentation Classification and taxonomy of insects Basic principles of taxonomy on slides
Classification and taxonomy of insects Basic principles of taxonomy Insects constitute the largest group of animals on earth. There are about 2 million species. To understand this diversity of insects, it is necessary to systematize them, that is, to combine them into groups according to the degree of relatedness and distribute these groups (taxa) in a certain ordered system. The main goal of taxonomy is to separate the enormous diversity of insect individuals into easily recognizable groups, identify the diagnostic characters of these groups, and establish differences between similar groups. The main taxa are: species, genus, family, order, class and phylum. In insect taxonomy, a number of intermediate categories are used: subgenus, tribe, subfamily, suborder, superorder, infraclass.
The most important taxonomic unit in taxonomy is the SPECIES - a set of similar individuals that occupy a certain geographical area and, when crossed, produce fertile offspring that retain similarities with their parents. Under the influence of environmental variability, intraspecific forms arise. These include subspecies, ecotype and population. A subspecies (geographical race) represents a change in a species associated with the peculiarities of living conditions in different parts of its range. An ecotype is an ecological race that arises when a species spreads to new habitats that differ in environmental conditions. A population is a collection of individuals of the same species that occupies a certain area for a long time and reproduces for a large number of generations. To designate a species, a binary nomenclature is used, consisting of two Latin words - genus and species. The letter after the species name indicates the surname of the author who first described this type. For example, Bupalus piniarius L.
Classification Currently, according to the “Identifier of Insects of the European Part of the USSR” G. Ya. Bei-Bienko proposes dividing the class of insects into two subclasses: primary wingless (Apterygota) and winged (Pterygota). Subclass 1. Lower, or primary wingless Insect orders included in the first subclass (neckless, springtails, two-tailed, bristletails) are low organized, do not have wings, and are very small. They are found in the forest floor and do not harm woody plants. Subclass 11. Higher, or winged. The winged subclass is divided into two sections: with incomplete transformation (Hemimetabola) and complete transformation (Holometabola).
Order Orthoptera Large and average size insects with hopping hind legs. There are two pairs of wings, the anterior ones are parchment-shaped, the posterior ones are wide, membranous with reticulate veins, folding fan-shaped. Mouthparts are gnawing. Females of many species have a saber-shaped ovipositor. The order includes families: grasshoppers, crickets, mole crickets, and locusts. Many species are herbivorous, and there are also predators. Pests of field crops are migratory locusts, Moroccan locusts, and Italian locusts. Species of the mole cricket family are distinguished by digging front legs, the head is directed with the mouth forward, and there is no egg-cloth. They damage plant roots, including causing significant damage in forest nurseries.
Order Earwig Insects of medium size (5-20 mm). The body is elongated, flexible, the head is prognathic, the antennae are 8-50 segmented. The pronotum is small, the anterior pair of wings is transformed into short leathery, veinless elytra, the posterior pair is membranous, folds lengthwise and transversely at rest, the legs are walking, the abdomen of the female bears a pair of cerci in the form of hard mites, which are an organ of defense and attack. They feed on animal and plant foods, mainly polyphagous predators. Common and garden earwigs can harm plants, especially indoors and in greenhouses.
Order Homoptera Various in external structure and body size of insects. Wings, if present, are folded like a roof; there are two pairs of them. Many representatives are characterized by polymorphism. The mouthparts are piercing-sucking. They feed on the cell sap of plants, which often suffer significant damage. The intestine is structured in a unique way: the end of the foregut is fused with the end of the middle or the beginning of the hind intestine, forming a filtration chamber through which water with a solution of sugars penetrates into the hind intestine. The body gets rid of water ballast and sugars, which is why a sweet coating forms on the plants - honeydew, or honeydew. Many representatives are carriers of viral and mycoplasma diseases.
Suborder Cycads Cycads are insects of different sizes; have short, bristle-like antennae and legs with thickened thighs, and jump well. Small cicadas live among the grass in meadows and in crops of cultivated plants, sucking them out. Field crops are damaged by the dark leafhopper, six-spotted leafhopper, and striped leafhopper. In addition to direct harm, they are also carriers of viral diseases. Damage to tree species can be caused by mountain, white-winged, comb, song and other leafhoppers. Damage is caused by females at the time of laying eggs, when they make deep cuts with their ovipositor on branches and shoots. The larvae live in the soil for several years and suck tree roots.
Suborder psyllid Insects are similar in appearance to small cicadas, but with long 10-segmented antennae, the front pair of wings with a thickened costal vein, just like cicadas, they are able to jump. The larvae are flattened, outwardly little similar to adult insects, when feeding on the leaves of trees and shrub plants secrete honeydew. Psyllids often form massive clusters on plants. Most species have a narrow food specialization. Noticeable damage is caused by apple, pear and sucker psyllids.
Suborder whiteflies Very small (less than 2 mm) insects that resemble microscopic moths with wings and a body covered with white powdery pollen. There are two pairs of wings with greatly reduced venation, folded flat on the abdomen. The larvae are flat, the body is covered with a waxy formation. Adults and larvae feed on the sap of various plants. The maple whitefly is often found in the forest. They are often found on the underside of leaves, especially in damp and shady places; form clusters. The greenhouse whitefly harms greenhouse and indoor plants, and the citrus whitefly severely damages citrus fruits on the Black Sea coast of the Caucasus.
Suborder of aphids Small insects (0.5 -7.5 mm), oval in shape, colored to match the color of the substrate. The integument is soft, often with a waxy coating. Wings, if they have them, are transparent, folded like a roof. Abdomen with juice tubes. Aphids are characterized by polymorphism, alternating bisexual and virgin generations. There are migratory and non-migratory species. They harm both wood and herbaceous plants. They usually inhabit young growing shoots and foliage, the cell sap of which is rich in proteins; few species live on roots, others form galls. The suborder is divided into superfamilies: aphids themselves and hermes. Harmful species: legume, blood, grape phylloxera, spruce-larch Hermes, etc.
Suborder coccida (bugs and scale insects) Very small insects with sharp sexual demorphism. The female's body is greatly reduced. They are wingless, immobile and resemble growths on the bark. The secretion of the wax-secreting glands goes to the formation of the scutum or egg sac. Representatives of the mealybug family are covered with a powdery coating that resembles flour. Males have one pair of wings, the mouthparts are reduced, the legs are normally developed, and the body is smaller than that of females. Parthenogenesis is widely developed among them. Many species are serious pests of fruit crops, shrubs and ornamental plants: willow, comma-shaped, Californian scale, Australian grooved bug, citrus mealybug, soft false scale.
Order Hemiptera, or bugs. Mostly small and medium-sized insects with a flat body. There are two pairs of wings, the front wings are leathery at the base, membranous towards the apex, the rear membranous are transparent, sometimes the wings are shortened or absent. The mouthparts are piercing-sucking. The metathorax from below in adults often has scent glands. They feed on plant cell sap and have predators or bloodsuckers. In addition to land species, there are aquatic forms (smooth striders, water striders). Tree species are harmed by flat bugs (pine bedbugs), and pests of cultivated plants include tortoiseshell bugs, alfalfa, beet and other species.
The order Fringed Pterus, or thrips, are very small insects (0.5 -5 mm) with an elongated body. Wings with atrophied venation, narrow, edged with a fringe of long cilia. The mouthparts are piercing-sucking type. The tarsi have a small bubble-shaped sucker. They suck out plant juices. In forests, larch thrips harms young plantings. Flower plants, especially in closed ground, they harm tobacco, greenhouse thrips, and agricultural crops: peas, wheat, clover and others.
B. Infraclass New Pterans Section 11. Insects with complete metamorphosis Insects have four phases of development: egg, larva, pupa and adult insect (imago). The larvae are non-imaginous, differ sharply from adults in body structure and lifestyle, and lack compound eyes. The wings develop under the skin of the larva and only from the pupal stage become external structures. Therefore, insects with complete metamorphosis are also called endopterygotes, i.e., with internal wing rudiments. The department is divided into 3 superorders - coleopteroids, neuropteroids and mecopteroids.
Superorder Coleopteroidea Mouthparts are typically gnawing. The hind wings perform a flight function, while the front wings are transformed into opaque elytra or reduced. The abdomen lacks a cerci and primary ovipositor. The larvae are always without abdominal legs, worm-shaped or campodeoid. Order Coleoptera, or beetles. This is the largest of the orders in terms of the number of species. Insects are diverse in size, structure and lifestyle. Among beetles there are predators, herbivores, consumers of animal and plant residues, terrestrial, soil and aquatic forms.
Family Rove beetles Beetles have greatly shortened elytra. The larvae are campode-shaped. Beetles and larvae live in rotting organic matter, under the bark, in moss, etc. Many species are predators, for example, the aleochre beetle.
The family Lamellate beetles have lamellar antennae. The larvae are thick, C-shaped with 3 pairs of legs, and live in the soil. Forest pests are Khrushchev: May, June and others.
Click beetle family The body is flat. The fore-back is elongated with pointed lateral corners. Larvae with a hard, thin body, called wireworms, live in the soil. Many species are phytophagous - dark, striped, sowing, wide.
Darkling beetle family Most beetles have sclerotinized integuments and black body coloration. Often the elytra grow together and then there are no wings. The larvae have a long pair of front legs, a convex head and are called pseudowires. Beetles and larvae are phytophagous: sand slugger, steppe slugger, broad-breasted slugger.
Family of ladybugs, or coccinellids. Beetles with a strongly convex rounded body. Many species are brightly colored with spots on the elytra. The larvae are campodeoid, covered with hairy warts. Predatory species (beetles and larvae) destroy aphids, psyllids, coccides, spider mites. Useful species: seven-spotted ladybird, two-spotted adalia, rhodolia.
Family of longhorned beetles, or woodcutters. The body of beetles is elongated. The antennae in most species are longer than half the body and are thrown back onto the dorsal side of the body. The larvae are thick, soft, have no chest legs and live under the bark, in wood, and sometimes in plant stems. They cause great harm by making passages in the trunks and branches of trees. Black pine longhorned beetle, large oak longhorned beetle.
Carabid family Beetles with running legs, usually black, sometimes with metallic paint. The larvae are campodeoid. Most species lead a predatory lifestyle, exterminating caterpillars, larvae, eggs, and pupae of other insects. Forest jumper, fragrant beetle, bronze beetle, Shcheglov's beetle, flat beetle, convex beetle, common platysma, etc.
The family of leaf beetles most have a short body, metallic colored, antennae are often shorter than half the body. The larvae are ovate, with developed thoracic legs. Beetles and larvae feed on leaves, buds, and annual shoots. They cause great harm in nurseries and young animals. Leaf beetles: poplar, viburnum, alder, birch bark, oak flea beetles.
Family Weevils The head of beetles in the anterior part is elongated and forms a rostrum. The antennae are geniculate and geniculate-club-shaped. The larva is worm-shaped, legless, C-shaped and curved. Acorn weevil, gray and blue pine weevil, large pine weevil, pinpoint tar weevil.
Tubeworm family Beetles are similar to weevils. They are distinguished by non-geniculate antennae, the body is shiny, naked, the elytra are almost quadrangular. The larvae live in leaves of tree species rolled up into a tube, including fruit ones. Black birch trumpet-vert, walnut trumpet-vert, cherry elephant, goose.
Family of bark beetles The body of beetles is cylindrical, the antennae have a short club, the rostrum is short, the pronotum is large, often longer than a third of the body. The larvae are legless, curved, and live in passages under the bark of trees. Great pine beetle, typographer, apical bark beetle, engraver, birch sapwood, ash pine beetle, pygmy sapwood.
Family borer The body of beetles is flat, elongated, narrowed towards the end, metallic-shiny. The head is small, the antennae are serrated, and the legs are short. The larvae are solo elongated, legless, yellowish-white. Some of them live under the bark, feeding on bast and sapwood, others on wood. Blue pine, green narrow-bodied, bronze oak, etc.
Superorder Neuropteroides Mouthparts are typically gnawing. The wings are mesh. The prothorax is well developed. The larvae are campodeoid, the pupa is free, without a cocoon. The larvae lead a predatory lifestyle, destroying aphids, coccids, mites and other insects.
Order Reticulates Family Goldeneyes Insects with a delicate body, filamentous antennae and both pairs of reticulated wings equally developed. The body is colored greenish, the eyes have a shimmering gold color. The eggs are laid on the leaves on the stalk. The larvae are elongated, spindle-shaped, feed on aphids, destroying up to 400 aphids. The goldeneye is transparent.
Order Camelidae Medium-sized insects with a large, prognathic, posteriorly narrowed head. The prothorax is very mobile, greatly elongated. Legs are thin. The wings are membranous. The abdomen is elongated, the female has a distinct ovipositor. The larvae are terrestrial with gnawing mouthparts. Adults live on trees, feeding on aphids and others. The larvae destroy bark beetles under the bark.
Superorder Mecopteroides Insects with mouthparts of the sucking or modified gnawing type, less often gnawing. The wings are reticulate or membranous, most with a reduced or reduced posterior pair. The prothorax is poorly developed. The larvae are worm-like or caterpillar-like. , often with labial silk-secreting glands. The pupa is covered, in a puparia or in a cocoon.
Order Lepidoptera, or butterflies. Insects of various sizes with two pairs of membranous wings, densely covered with scales, giving them a beautiful color. The oral apparatus in the form of a spirally twisted proboscis is adapted for sucking nectar. The antennae are varied. Caterpillars have a head and a gnawing mouthpart, three pairs of thoracic and two to five pairs of abdominal legs, and are equipped with silk-secreting glands. Most caterpillars are herbivorous and damage cultivated plants and forests. Pupae are usually covered.
Family of ermine moths. Wingspan not more than 25 mm. The wings are narrow with a long fringe on the hind wings. Caterpillars live secretly, eat leaves, entwining them with cobwebs. Bird cherry, apple, cabbage, potato moths.
Glass butterfly family Butterflies have transparent wings with scales only at the edges, as a result of which butterflies are similar to bees or wasps. Caterpillars live under the bark or in wood, make passages and greatly damage the wood. Harmful species: dark-winged, large poplar, spotted, currant glass.
Leafroller family, Butterflies with a wingspan of no more than 25 mm. The front wings of butterflies are elongated triangular, the hind wings are elongated oval without fringe. Caterpillars are 10 -20 mm long, very mobile. Pupae in web cocoons. Harmful species: pine cone, green oak, hawthorn, gray larch, shoots: wintering, summer, bud resin.
Family of woodworms Butterflies with a wingspan of 23 -110 mm, the hind wings are much shorter than the front ones. Caterpillars live in the trunks and branches of trees and greatly harm tree species. Corrosive wood borer, odorous wood borer, aspen wood borer.
Moth family Butterflies with a thin body and relatively long legs, the front wings are obliquely triangular, the hind wings are oval, and at rest they usually fold into a flat triangle. Butterflies fly towards the light, hence the name of the family. The following moths damage forestry: cone moth, acacia moth
White butterfly family These are daytime butterflies of white, yellow, orange color with club-shaped antennae. Caterpillars are covered with dense short hairs. The pupae are attached to the substrate with a silk belt. Harmful: hawthorn, cabbage and turnip whites.
Family of cocoon moths Butterflies with a densely hairy body. The antennae of males are feathery, while those of females are comb-like. The proboscis is underdeveloped and the butterflies do not feed. The caterpillars are large, up to 120 mm, covered with hairs of varying lengths. They seriously harm tree and fruit species. Pine, Siberian, ringed silkworms.
The moth family The wings of butterflies are wide, the front ones are triangular, the back ones are rounded. The females of some species are wingless or with barely noticeable wings. Caterpillars have 10 legs and bend their body in an arc when moving; most species feed on leaves or needles. Dangerous species moths: winter, pine, gooseberry, fir, poplar, brown-striped, etc.
Volyanka family Butterflies with a thick hairy body and wide wings; the front ones are usually brownish-gray with dark jagged stripes along the outer edge, the rear ones are lighter. Sometimes females have no wings or are underdeveloped. The proboscis is underdeveloped. Caterpillars with warts. The pupae are brown. Oviposition is covered with hairs. Goldentail, gypsy moth, nun's moth, red-tailed moth, willow, ancient, larch moth.
Owl family Butterflies of various sizes with a thick body. The proboscis is developed. On the front wings there are three transverse stripes, a sinuous sub-marginal line and three spots: round, wedge-shaped, kidney-shaped. Caterpillars are naked, 16-legged. The pupae are yellowish brown or black with a developed proboscis. Pine, cabbage, winter, exclamation scoop and others.
The family of hawk moths Butterflies are distinguished by spindle-shaped antennae, a long proboscis, a strong body with a conically pointed abdomen at the back and long wings, the back pair of which are shorter than the front ones. The flight is fast, they fly in the evening. The following types of hawk moths can cause minor harm: pine, lilac, and death's head.
Family of true sawflies. Mouthparts are gnawing. The abdomen is sessile, in females with a saw-toothed ovipositor. Eggs are laid in leaves, needles, and sometimes in shoots and buds. Larvae of the moth moth. Many live in nests. Pupa in a cocoon. Dangerous pests: common and red pine sawflies, star-shaped and red-headed weaver sawflies, gooseberry and currant sawflies.
Horntail family Insects with a long cylindrical body. Females sometimes carry a long egg-cloth; they use it to drill into the bark and lay 1-3 eggs. The larvae make passages in the wood, tightly clogged with drill flour. Large conifer, blue, purple, black horntail, alder and oak xyphidria.
Family of true gallworms. Small insects. They damage plants, forming galls within which all development takes place. Galls form on leaves, buds, shoots and roots. Largest number The gallworm is found on oak and Rosaceae. Harmful types of nutworm: grape-shaped, pineal-shaped, apple-shaped, common oak.
The suborder long-whiskered flies are distinguished by multi-segmented antennae, which are usually no shorter than the head and chest. The legs are long and thin. Larvae with a small head, worm-like. The pupae are free, but usually without a cocoon. Many species live in damp places. Some species are serious plant pests. In nurseries, root systems of seedlings are damaged, and weevil larvae cause damage to turf on lawns; Young tree and shrub species are harmed by gall midges: willow stem gall midges, larch bud gall midges, red pine gall midges, etc.
The suborder short-whiskered flies are very diverse in their structure. The antennae are short, 3-segmented. Larvae without a head or with a rudimentary retractable head. A doll with or without a false cocoon. Pests of tree and shrub species are: spruce pine and larch flies, leaf miners, onion hoverflies. Exterminators of harmful insects: blackbirds, hedgehogs (tahins).
Subgenus - subgenus
species
Subspecies
The most important taxonomic unit is the species. However, the concept of a species is constantly expanding and clarifying. Until the twentieth century, taxonomy was based almost exclusively on morphological characters.
Currently view is considered as a historically established community of organisms, similar to each other in terms of structural features and environmental requirements, freely producing fertile offspring when crossed, populating a certain area of distribution and qualitatively different from other species.
However, the above definition of a type does not cover all its properties. In reality, a species is an infinitely complex biological phenomenon that defies succinct formulation. Modern system tika in the knowledge of species uses data from biochemistry, cytology, physiology, genetics down to the molecular level. A species can be likened to an atom in physics and, like the latter, is inexhaustible.
There is a qualitative gap between true species—geatus—at least in one or two characteristics. This gives them qualitative certainty. A characteristic feature of the species is the presence in it of intraspecific forms that arise under the influence of environmental variability. In this regard, the following intraspecific forms are distinguished:
Subspecies
Ecotype - ecotipus
Population
Subspecies often called a geographical race, arising under the influence of different conditions of existence of the species in different parts of the range.
To designate subspecies, triple (or trinary) nomenclature is used, for example: Locusta migratoria L.
Central Russian locust - Locusta migratoria rossica uv. et Zol. ,
In France - L. migratoria gallica Rem. ,
In southeast Asia - L. migratoria manilensis.
Ecotype- an ecological race that arises when a species masters new living conditions; they usually inhabit small areas and are not morphologically different. For example, blood aphids in America (on American elm) and in Europe (on apple trees) are a food form. Willow leaf beetle on birch and willow.
Population. The lower intraspecific taxonomic unit is population– a group of closely related individuals forming separate settlements, located in separate spots and, as a rule, separated. A population is the basic unit of existence of a species in nature.
All the categories discussed above are various forms spatial separation of the species. Variability can also manifest itself in forms that coexist together (polymorphism, gregarious and solitary forms of locusts, etc.). One very common form of variability is color deviations - aberrations. Intraspecific forms are considered as forms of existence of a species in a changing environment; they expand the capabilities of the species and ensure its prosperity. Therefore, thriving species have a more complex structure.
Principles of insect classification
The degree of relationship between modern insects is determined on the basis of data from paleontology, comparative embryology, morphology, and anatomy of insects. By sequentially distributing groups of insects from primitive to highly organized forms, the classification attempts to schematically display the path of phylogenetic development of the entire class and the degree of relatedness of large and small systematic units.
The deeper we understand the properties specific types, genera, families, etc., the closer we come to constructing a natural classification. Determination of the location of insect complexes in the general natural system class constitutes the classification problem.
The modern classification of insects is the result of research by many generations of scientists. At the beginning of the 19th century, a division was established into insects with complete and incomplete transformation. Then the German scientist Bauer (1885) established the heterotypicity (heterogeneity) of wingless animals - primary wingless and secondary wingless.
Then the Austrian scientist A. Gandlirsch eliminated the cumbersome orders and introduced more detailed divisions into orders into the taxonomy of insects, bringing them total number to 30 plus, and made them more natural.
A major contribution was made by the Russian entomologist A.V. Martynov, who gave an analysis of the class of insects by comparing fossil forms with living ones, subdividing insects into ancient and new-winged insects, giving a coherent system and classification, which has been preserved in its main features to the present day (1938).
Subsequently, Russian researchers B.B. Rodendorf and B.N. Shvanvich showed that the evolution of wings occurs due to the emergence of functional diptera, which then turns into morphological (Diptera). The principles of dipterization (the Rodenford-Schvanvich principle) were an important aspect of the modern classification.
And finally, in lately it was found that the subclass of primary wingless animals is not homogeneous. Among them, Bristletails have a non-submerged mouthparts (ectognathous) and are closer to winged ones, and the other three orders have a submerged mouthparts (entognathous). Some researchers distinguish them into a separate subclass, and even a class.
Outstanding Russian scientists Kholodkovsky, Kuznetsov, Plavilshchikov, Zakhvatkin, and Bei-Bienko made a major contribution to the development of taxonomy.
4. Modern insect class system
Currently, the class of insects (Insecta) is divided into two subclasses, including 34 orders with many intermediate units (4 infraclasses, two divisions and 5 superorders).
In general, the classification of insects can be presented as follows:
I. Subclass lower, or primary wingless - Apterygota
A. Infraclass entognatha - Entognatha
1) Protura squad, or bessyazhkovye - Protura
2) Podura squad, or springtails - Podura
10) Stonefly order - Piecoptera
11) Embioptera order
12) Grylloblattida order - Grylloblattida
13) Order of stick insects - Phasmatoptera
14) Orthoptera order - Orthoptera
15) Order hemimerida - Hemimerida
16) Order Leatheroptera - Dermaptera
17) Zoraptera order - Zoraptera
Superorder hemipteroids - Hemipteroidea
18) Order of hay eaters - Psocoptera
19) Order of lice eaters - Mallophaga
20) Louse order - Anoplura
21) Order Homoptera - Homoptera
23) Thrips order - Thysanoptera
Department with complete transformation - Holometabola
Superorder coleopteroids - Coleopteroidea
24) Order of beetles - Coleoptera
25) Order fanwings - Strepsiptera
Superorder Neuropteroidea - Neuropteroidea
26) Order Opticoptera - Neuroptera
27) Camel order - Raphidioptera
28) Order Bigwings - Megaloptera
Superorder Mecopteroids - Mecopteroidea
29) Order of scorpion flies - Mecoptera
30) Order of caddisflies - Trichoptera
31) Butterfly order - Lepidoptera
32) Hymenoptera order - Hymenoptera
33) Flea order - Aphaniptera
34) Diptera order - Diptera
5. Subclass lower, or primary wingless - Apterygota
The insects included in this subclass are the most poorly organized, wingless, and this winglessness is primary, since they do not have wings and never have had them (even in the embryonic state). On the first segments of the abdomen there are appendages - the remains of walking limbs or a jumping fork. At the end of the abdomen there are often cerci or caudal filaments. The mouthparts are gnawing (sometimes piercing).
The transformation is primitive, weakly expressed - protometabolism or anamorphosis. The larvae are similar to adults and molt repeatedly. The adults of many species are capable of molting. Most species lead a hidden lifestyle and are closely associated with the soil. The subclass Apterygota (primarily wingless) is divided into two infraclasses and four orders.
A. Infraclass entognathae cryptomaxillary- Entognatha
Head without compound eyes. The mouthparts are piercing or gnawing, retracted into the head capsule (secreting jaws; in the structure of the mouthparts they are closer to millipedes). At the end of the abdomen, if there are cerci, then they are without a paired caudal appendage.
The infraclass is divided into 3 groups:
squad bessyazhkovye – Protura
order of podura or springtails – Podura (Collembola)
two-tailed squad – Diplura
Order Protura – Bessyazhkovye
Small (0.5 to 2 mm) pale insects with a worm-like and flexible body. The head is prognathic, devoid of eyes and antennae. The mouthparts are bristle-like, retracted into the head capsule. On the first three segments of the abdomen (12 segments in total) rudiments of legs have been preserved (in which these insects are also close to millipedes). Metamorphosis – anamorphosis (with molting the number of abdominal segments increases). Antennae are absent, but they are functionally replaced by forward-pointing long forelegs. Movement occurs only with the help of two pairs of legs. They lead a hidden lifestyle. Found under the bark of stumps, in rotting wood, under fallen leaves and in moss; They feed on decomposed plant debris, fungal mycelium and others. Poorly studied. Representatives: Eosentomon transitorum.
Order Podura (Collembola) – Springtails
The order is divided into two suborders: A) suborder arthroplasty - the body is elongated, the abdomen is jointed; B) suborder whole-bellied - the body is spherical, the abdominal segments are fused.
Small insects (1-2 mm), abdomen 6-segmented, on the 4th segment of the abdomen there is a jumping fork, on the 3rd there is a hook, and on the 1st there is an abdominal tube. U typical soil species the jumping fork is shortened, and the head is prognathic, the antennae are 4-6-segmented. The mouthparts are usually gnawing, but some can feed on liquid food, and the oral apparatus has a piercing-sucking function. Eyes are often present and small. They feed on plant debris, mycelium and spores of fungi, and bacteria. They play an important role in the soil-forming process. Very demanding on moisture and not demanding on temperature. Abundant in the Arctic and Antarctic. They can appear in the snow in our latitudes.
They reproduce in a peculiar way. Males deposit spermatophores in the form of droplets on stalks, and females capture them with their genitals.
Among the springtails there are serious agricultural pests: Sminturus viridis - green springtail, Bourletiella lutea - vegetable springtail - they harm vegetable and other crops.
Order Diplura – Double-tailed
Small (2-8 mm) insects with a worm-like flexible body, covered with small branching hairs. The head is large, prognathic with multi-segmented antennae. No eyes. The mouthparts are directed forward, although hidden in the head capsule. The upper jaws are sickle-shaped and serrated. The thoracic segments are well defined. The legs are long, the abdomen is 11-segmented, and most pregenital segments have paired styli.
They can run forward and backward. At the end of the abdomen the cerci are always well developed, and in this case. Campodeidae have multisegmented cerci, while in the family Iapygidae the cerci are claw-shaped and single-segmented. Representatives of the order are inhabitants of southern latitudes, most are predators, less often saprophages and necrophages. Representatives: Campodea plusiochaeta, Iapyx confuses
Infraclass Thysanura (thysanuraceae) – Bristletails
The oral organs are positioned freely (not retracted inward). The eyes are compound. At the end of the abdomen there are multi-segmented cerci and an unpaired caudal appendage. Has one squad.
Order Thysanura – Bristletails
The body is elongated, fusiform. The head is narrower than the chest. The antennae are long, multi-segmented, thread-like, there are compound eyes, and between them there are three simple ocelli. The legs end in two claws. The chest smoothly passes into an 11-segmented abdomen tapering towards the rear, at the end of which there is a pair of long segmented cerci, and between them an even longer caudal filament. On the abdominal segments of the bristletail there are styli, which are the remains of walking limbs. Bristletails rely on these styli when moving. The body and styli are covered with delicate thin oily scales, giving the bristletails a silvery shine. They create a layer impenetrable to evaporation. At the base of the styli there are protruding vesicles with very thin covers. By touching them to a wet surface (soil, rocks), they replenish their water supply. They live a long time - up to three years, and molt as adults. They live under stones, fallen tree trunks, in forest litter, in soil, anthills, in houses, shops, libraries, where they damage books, food supplies, cereals, bread and sugar.
Lepisma saccarina – sugar silverfish – “silver fish”
Termobia domestica - home thermobia.
7. Subclass Higher or winged - Pterygota
This subclass includes all winged ones, as well as secondary wingless ones, that is, insects that have lost their wings during the process of evolution. The abdomen of higher insects does not have appendages on the pregenital segments.
This huge, diverse subclass is divided into two infraclasses, two divisions, five superorders and 30 orders. It is characterized not only by a colossal number of morphological forms, but also by dramatically different forms in biology and habitat.
8. A. InfraclassPaleoptera– Ancient Wings
The wings of representatives of the infraclass are not able to fold along the body. They keep them spread out and raised upward (the costal edge of the wing points downwards). The southern region is not developed. All this limits the ability to occupy secluded places (a more primitive and ancient feature). Head with large compound eyes, antennae shorter than head. Abdomen with cerci, sometimes an unpaired caudal process. The transformation is incomplete; the larvae live in water. Modern insects belonging to the ancient wings have only two orders:
Ephemeroptera - mayflies, Odonatoptera - dragonflies.
Order Ephemeroptera – mayflies
1600 species of small and medium-sized, delicate insects with soft covers and an elongated body. The head is large and very mobile. The oral organs are atrophied. The wings are mesh, delicate, the front ones are larger than the back ones. The abdomen is thin, long, 10-segmented, at the end of the abdomen there are 2-3 caudal filaments. They molt as adults (protometaboly). A very unique and primitive reproductive system; two genital openings in females and a paired penis in males have been preserved. Primitiveness is indicated by the presence of tail filaments and the development of larvae in water. The eggs are laid in water. The development of larvae in water takes 1-3 years. The larvae are naiads and have external tracheal gills. Having completed development, the larvae molt, turning into an immature winged individual - a subimago, which after molting turns into an imago.
The flight is accompanied by a kind of dance - vertical take-offs and descents. Adults live very briefly - hence the name of the order. Larvae and adults serve as food for fish. The most common is Ephemera vulgata - the common mayfly.
Order Odonatoptera – Dragonflies
4500 species, in the Russian Federation - 165. Large and medium-sized insects with a large, very mobile head, very large eyes, short, barely noticeable antennae, and gnawing mouthparts. The wings have a dense network of veins, almost the same size and shape, usually spread to the sides. The abdomen is 10-segmented, long, thin or flat, at the end of the cerci. Eggs are laid in water or on aquatic plants. The larvae are naiads, they breathe with gills (often located in the rectum), with a strongly overgrown lower lip (mask), which serves to capture food; They lead a predatory lifestyle, feeding on various insects and fish fry. The larvae themselves serve as food for fish. Before turning into an adult insect, the nymph emerges from the water. Adult insects are characterized by fast flight (96-144 km/h), lead a predatory lifestyle, feed on various insects, catching them in flight, exterminating mosquitoes and other harmful insects.
Representatives: Sem. Aeschnidae – rockers – large, variegated, chest and sides with light, yellow stripes. Aeschna grandis - large rocker.
Knowledge of taxonomy is necessary for correct diagnosis - identification and identification of harmful and beneficial insects. There are 34 orders in the class of insects, the most significant of them in agricultural practice are presented below (Protection of plants from pests, 2002).
Class Insects - Insecta. Subclass Primary wingless - Arterygota.
A small group of insects with a complete absence of wings retain rudiments of abdominal limbs. Mostly small, secretively living insects, saprophages, herbivores or predators. Representatives: springtails, bristletails.
Subclass Winged - Pterygota.
Includes the vast majority of insects. Wings, as a rule, are developed, and if absent, the structural features associated with the wings are preserved. There are no abdominal limbs. Orders of winged insects are united into two large divisions, differing in the type of development.
Department Insects with incomplete metamorphosis - Hemimetabola. Order Orthoptera - Orthoptera.
Large and medium-sized insects. The body is elongated, often laterally compressed. The antennae are long, usually filamentous or bristle-like. The mouthparts are gnawing. The front wings are elongated, rectangular, leathery. The hind wings are wide, fan-shaped, membranous. The venation is reticulate. The hind legs are jumping. Females have a developed ovipositor. Males have developed sound apparatus. They live mainly in herbaceous and tree-shrub vegetation. Many are agricultural pests. The order is divided into suborders: long-whiskered - grasshoppers, crickets, mole crickets and short-whiskered - locusts.
Order Hemiptera or bugs - Hemiptera.
Order Homoptera - Homoptera.
Various in appearance, mostly small insects. The antennae are usually filamentous or bristle-like. The mouthparts are piercing-sucking. Both pairs of wings are membranous, less often the fore wings are leathery. The fore wings are more developed than the hind wings. The venation is membranous. Wingless forms are often found. Some species have developed jumping legs. Many have wax-secreting skin glands. Most live on herbaceous and woody vegetation. All homoptera are herbivorous. The order is divided into 5 suborders: cycads, flea beetles, whiteflies, aphids, coccids (bugs and scale insects). Each of them contains agricultural pests (dark leafhopper, apple honeydew, greenhouse whitefly, pea aphid, and yellow scale insect).
Order Fringedwings or thrips - Thysanoptera.
Small insects with an elongated narrow body. Antennas are short filamentous. The mouthparts are piercing-sucking with a short proboscis and three piercing setae. The wings are elongated, very narrow, membranous, fringed. The venation is membranous and poorly developed. The legs are walking, with small retractable suckers at the ends of the legs. Females often have a developed ovipositor. Most thrips are herbivorous (wheat, flax, tobacco thrips).
Insects with incomplete transformation also include the orders of mayflies, dragonflies, cockroaches, mantises, earwigs, termites, stick insects, lice, etc.
Order Insects with complete metamorphosis - Holometabola.
Order Coleoptera or beetles - Coleoptera.
Sizes from small to large. The mouthparts are gnawing. Powerful protective hard front fenders (elytra). The hind wings are elongated, membranous with membranous venation. In flight, only the rear wings work. In addition to normal walking and running legs, some representatives have swimming, digging and jumping legs. The larvae have a varied structure - worm-shaped and campodeoid, with or without legs. Most pupae are open. The order has many predators that destroy harmful insects (most ground beetles and ladybugs, rove beetles). Many different agricultural pests are known in the families: lamellar beetles (grain beetles, chafer beetles), click beetles (striped beetles, sow beetles), darkling beetles (sand beetles, mealworms), longhorned beetles (black spruce beetle, sunflower beetle), leaf beetles (Colorado beetle, grain beetles, beet and cruciferous flea beetles, beetroot), weevils (pea, bean), weevils (beet, root nodule, apple flower beetle), etc.
Order Reticuloptera - Neuroptera.
Various, medium-sized insects with an elongated thin body and large membranous wings with reticulate venation. The mouthparts are gnawing. Most are on the ground, flight is moderate. All lacewings are predators and can be useful by destroying pests. The most famous representatives: lacewings, antlions.
Order Lepidoptera or butterflies - Lepidoptera.
Insects with a relatively thin body and large membranous wings with scaly pubescence. Sizes from small to large. The oral apparatus is sucking. The fore wings are slightly more developed than the hind wings. The venation is membranous. The legs are simple, walking. The larvae are caterpillar-shaped, the pupae are covered. Adults fly actively, most feed on nectar. Most caterpillars are terrestrial, less often soil-based, and feed on various parts of plants. The largest number of pests is known in the group of moth families (cloth moths, grain moths, apple moths, cabbage moths), leaf roller families (apple and pea moths), moths (meadow and stem moths), white moths (cabbage moths and turnip moths), cocoon moths (ringed silk moths), moths (winter), moth (gypsy moth), armyworm (winter, gamma, grain, cabbage).
Order Hymenoptera - Hymenoptera.
Order Diptera - Diptera.
