Science and technology

Sexual dimorphism. One of the amazing phenomena that often occurs in Diptera is sexual dimorphism, i.e. significant differences in appearance between males and females of the same species. For example, as noted above, in males of many species, complex eyes are holoptic; touch each other, while in females they are separated by a frontal stripe (dichoptic). In female mosquitoes, antennae are weakly pubescent, while in males they are densely covered with long hairs. Sexual dimorphism can also be expressed in size: males are usually smaller. In females of some species, the wings are absent or strongly reduced, while in males they are normally developed. In one of the families of Diptera, in females, two wing veins merge at its edge, and in rare males they are separated along the entire length. In another group, the legs, antennae, or other body parts of males often bear tufts of hairs with a metallic sheen that are absent in females. The legs of the males of some mosquitoes are trimmed with a wide scaly fringe; females do not have it. Differences between sexes in color are common, but usually not striking. However, sometimes this difference is very significant; for example, the males of one American centipede are pale reddish, while the females are almost black.

Mimicry and protective coloration. Many species of harmless Diptera are strikingly similar in appearance to other insects, especially bees and wasps, which humans and probably other animals try to avoid. This phenomenon is called mimicry. Its typical example is the appearance of a series of hoverflies; they are so similar to wasps that even an entomologist will not always correctly identify an insect right away. Other hoverflies mimic the appearance of bees. Some flies are more or less like bumblebees. This similarity is reflected in the nomenclature of Diptera: the whole family Bombyliidae (buzzers) is named in Latin after bumblebees ( Bombus); there are bee-like hoverflies, bumblebee hoverflies, hornet hoverflies, etc .; one of the genera of knots is called Bombomima("Imitating bumblebees").

Some dipterans avoid predators with the help of a protective one, i.e. camouflage, coloring. The dark color of mushroom mosquitoes makes them invisible when they sit motionless in crevices under fallen trees. Other Diptera have a "dismembering" coloration. For example, in lyriopids, bright black and white stripes on the body are arranged in such a way that these insects, flying against a light or dark background, look just like sets of spots that do not fold into a single whole.

LIFE CYCLE Like other higher insects, the life cycle of Diptera is complex and includes complete metamorphosis. The eggs of most species are oblong and light. They hatch into larvae, usually elongated, approximately cylindrical, soft-bodied and legless. In most cases, the hard parts of the head are greatly reduced; such worm-like larvae are called maggots. The larva feeds intensively and periodically molts as it grows. The number of larval molts in Diptera is different, but usually there are two or three of them. Then comes the pupal stage. In some Diptera, it forms inside the larval skin, which turns into the so-called. Puparium. Eventually, the pupal membrane is torn apart, and an adult insect (imago) is born.

House fly life cycle. The house fly can be used to trace the development of Diptera. To lay eggs, the female looks for accumulations of decomposing organic matter, such as manure or garbage heaps. Thus, the fly instinctively leaves the clutch where the sedentary larva will be provided with a sufficient amount of food. At a time, the female can lay 120 or slightly more narrow, whitish eggs of approx. 1 mm long. Their huge masses are found in places where several females leave their clutches at the same time. At summer temperatures of 24–35 ° C, egg development takes approx. 8 ocloc'k. The worm-like larvae hatched from them are approx. 2 mm begin to eat greedily. They grow so fast that the first molt occurs in 24–36 hours, and the second one about a day later. In the third stage, the larva feeds for another 72–96 h and grows to a length of approx. 12 mm and then pupates.

An oblong pupa forms inside the last larval skin, which becomes a pupal sheath (puparium). This shell changes from off-white to brown and hardens. Within 4–5 days, inside an externally inactive pupa, the larval tissues disintegrate and rearrange, forming the structures of an adult insect. In the end, the imago comes out with the help of a special frontal bladder, which, under the pressure of the "blood" (hemolymph) pumped into it, protrudes in the frontal part of the head. Under its pressure, the puparium "lid" is thrown back, releasing an adult insect. It crawls out of decaying waste or the soil in which pupation has occurred, spreads its initially crumpled wings and flies away to feed and mate, launching a new life cycle.

Another curious form of reproduction found in some Diptera is pedogenesis, i.e. the appearance of offspring in externally immature individuals. Thus, in gall midges, the adult female lays only 4 or 5 eggs, of which large larvae are formed. Inside each of them, from 5 to 30 (depending on the species and on the individual) daughter larvae develop. They feed on the mother's body and then reproduce themselves in the same way. After several such cycles, the next larvae pupate, and the generation of adults is formed. Reproduction of larvae occurs without mating. This development of unfertilized eggs is called parthenogenesis. This phenomenon, in the absence of pedogenesis, was found in other Diptera, for example, in some midges. Females lay unfertilized eggs, from which only females emerge. Parthenogenesis can be cyclical, permanent, or sporadic. See REPRODUCTION;

GEOGRAPHICAL DISTRIBUTION On land, perhaps, there is no such corner where Diptera do not live. This is the most common order of insects, although the ranges of many of its families are not fully known. Each of the major zoographic regions is characterized by its own set of taxa, however, the genera and families to which they belong can be cosmopolitan, i.e. meet almost everywhere. About two dozen species of Diptera are also cosmopolitan. Man unwittingly settled about half of them all over the planet. These species include the ubiquitous housefly, squeaky mosquito ( Culex pipiens), gastric equine gadfly and autumn flare. Among about 130 families of Diptera, less than 20 are truly cosmopolitan, although the ranges of many others are not much narrower, i.e. they are sub-cosmopolitan.

Diptera abound in the humid tropics. The distribution of most of the families of this natural area and is limited, while many others reach their maximum diversity and abundance here. In temperate or cold areas, fewer Diptera species are found per unit area, but their numbers are often not lower than in the tropics. In the windswept Arctic desert, on mountain tops and among the dunes, where the harsh climatic conditions are not suitable for most insects, Diptera remain the most visible representatives of this group of invertebrates. In northern Greenland, a few hundred kilometers from the North Pole, there are centipedes, carrion flies, flower girls, bells and mushroom gnats. On the other side of the Earth, on the Antarctic islands, there are several species of midges, hoverflies, centipedes, gall midges and some other groups. In Antarctica itself, only one species of wingless mosquito has so far been noted, but it is likely that other Diptera will be found there.

Diptera of mainland islands are usually close to those living on nearby continents, but on more isolated oceanic islands, they, even belonging to widespread groups, are often very peculiar. Apparently, a single, accidental entry of some species on such islands in the distant past led in the course of evolution to the appearance of a whole set of various forms. This may explain, for example, the fact that almost a third of the 246 Hawaiian Diptera species belong to just one family.

ECOLOGY Possessing thin integuments, most Diptera are unable to effectively retain water in the body. They would be constantly threatened with drying out if they did not live in more or less humid conditions. Although the larvae are in many cases aquatic, the adults are almost always terrestrial. The only exception is sea centipedes Limonia monostromia, whose entire life cycle takes place in warm sea waters off the coast of Japan.

Larvae. The habitat of Diptera larvae is much more diverse than that of adults, and includes almost all types of ecological niches. Some attack aphids or gnaw the leaves of mosses and other plants, i.e. live openly. However, in most cases, they develop in the thickness of a moist substrate, for example, inside the leaves, stems and roots of plants. The larvae of many species make holes in decaying wood, fungi, or soil, feeding on organic debris or microscopic invertebrates.

They often live in stagnant and flowing water bodies of all sizes, where they feed on vegetation, microorganisms or other insects. Most of these aquatic larvae prefer shallow areas, but in some bell mosquitoes they dive deeper than 300 m. If their development requires a good supply of oxygen, they attach to the rocks of river rapids or mountain streams. The larvae and pupae of some Diptera prefer water with a high alkali or salt content, and in one Californian species they inhabit oil puddles. Others are found in hot springs and geysers, where the water temperature reaches 50 ° C. The larvae of one of the mosquitoes survive even in the liquid that fills the pitcher leaves of carnivorous plants, where other insects drown and digest.

EVOLUTIONARY HISTORY Judging by the fossil finds, insects existed already in the Devonian period, i.e. OK. 300 million years ago. However, until the Upper Triassic (about 160 million years ago), no remains of Diptera were found among them. The most primitive representatives of this order are similar to centipedes and are united in the extinct family Architipulidae. Many different dipterans, close to modern forms, are found in Baltic amber - the resin of coniferous trees, petrified in the Upper Oligocene, i.e. about 35 million years ago. In the Miocene schists from Florissant (Colorado), many fossil centipedes, mushroom gnats, and other dipterans characteristic of swampy habitats have been found. Among them, even the tsetse fly was noted, although at present this genus is found only in Africa. The study of Baltic amber and Florissant fossils showed that by the middle of the Cenozoic era Diptera had passed most of their evolutionary development.

VALUE IN HUMAN LIFE Many Diptera species are best known as vectors of disease, annoying bloodsuckers, and crop pests. Most effective chemical methods fight against them, however, even the latest insecticides cannot be considered a panacea, since insects quickly acquire resistance to them (resistance).

Carriers of human diseases. Listed below are just a few medically important Diptera.

Housefly mechanically transfers the causative agents of bacterial dysentery; it is possible that it can also spread the bacteria typhoid, paratyphoid, cholera and the polio virus.

Blind can transmit tularemia pathogens from an infected animal, as well as one of the filariasis - loiasis.

Cereal flies of kind Hippelateseating near the eyes, they easily carry a bacterium into them, which causes acute epidemic conjunctivitis.

Sucking blood. Blood-sucking dipterans, even without being carriers of diseases, for example, biting midges, an autumn burner, many mosquitoes and midges, in case of a massive attack, worsen the state of human health, causing itching and allergic reactions, sharply reducing performance. In addition, all of these species remain potential carriers of disease agents.

Pests of agricultural plants. Compared to beetles, butterflies, herbivorous bugs and representatives of some other orders of insects, Diptera do relatively little harm to agricultural plants. Representatives of only 5-6 families have a certain value in this sense. The Hessian fly from the gall midge family is one of the serious pests of cereals. This species mainly damages wheat, but also damages barley and rye. The larvae of the Hessian fly feed on plant sap at the base of the stems, causing their growth retardation and lodging. With the development of wheat varieties resistant to such damage, the importance of this agricultural pest has decreased. The variegated family includes many species that feed on the succulent fruits of various plants, but only a few of them cause serious damage. So, the larvae of the apple variegated fly spoil apples, damage the fruits of citrus and other fruit trees, significantly reducing the yield. Larvae of other Diptera gnaw tunnels in various plants. As an example, we can cite three species from the flower girl family: sprout, spring cabbage and onion flies. Representatives of the family of cereal flies, which live in many parts of the world, harm crops.

CLASSIFICATION The order Diptera is divided, according to different systems, into 121–138 families, which are grouped into two or three suborders. The classification most often uses such features as wing venation, the length of the antennae and the number of segments in them, the number and location of setae and spines on the body and legs, the configuration of the external genital appendages, the presence or absence of simple eyes, and the shape of the opening through which the imago leaves the pupal skin or puparium. The color, size and shape of the body do not always allow us to judge the degree of kinship, because natural selection often leads to external similarity of representatives of very distant groups. The scheme proposed below, which includes only the most important families, is only one of the possible ways to classify approximately 100,000 Diptera species; the number of species in families is approximate.

Suborder Nematocera (long-necked). These insects are characterized by long antennae with more than three segments. The group includes 36 families. Antennae in adults consist of 6 or more approximately identical, movably connected segments, and the mandibular palps usually consist of 4 or 5. The larvae have a well-developed dark-colored head capsule. The pupa is not enclosed in a larval skin, i.e. puparium is not formed.

Tipulidae (centipedes): 10,000 species, cosmopolitan.

Psychodidae (butterflies): 400 species, subcosmopolitan.

Chironomidae (bells, or jerguns): 2000 species, cosmopolitan.

Ceratopogonidae (biting midges): 1500 species, subcosmopolitan.

Culicidae (true mosquitoes): 1600 species, cosmopolitan.

Mycetophilidae (mushroom gnats): 2,400 species, cosmopolitan.

Cecidomyiidae (gall midges): 4500 species, subcosmopolitan.

Bibionidae: 500 species, mainly in Eurasia and North America.

Simuliidae (midges): 600 species, subcosmopolitan, but especially numerous in Eurasia, North and South America.

Blepharoceridae (retinaflies): 75 species, native to the highlands.

Suborder Brachycera (short-necked) includes about 100 families. The antennae of adult insects consist of three segments, of which the last (distal) one is thickened and bears an appendage in the form of a bristle or rod on the dorsal side or apex. Palp with one or two segments. The head of the larva is poorly formed or rudimentary. In representatives of some families (longitudinal), the pupa is free; in other cases (round-seam dipterans) develops inside the puparium.

Tabanidae (horseflies): 3000 species, mainly in the tropics and subtropics.

Stratiomyiidae (lion cubs): 1500 species, subcosmopolitan.

Rhagionidae (snipe): 500 species, mainly in North America and Eurasia.

Nemestrinidae (long-proboscis): 250 species, subcosmopolitan, but mainly in Central and North Africa.

Bombyliidae (buzzers): 2000 species, subcosmopolitan, but mainly in North America and the Mediterranean.

Asilidae (ktyri): 5000 species, subcosmopolitan, but most diverse in the tropics.

Mydaidae: 200 species, distributed in many but isolated regions.

Dolichopodidae (greenfinches): 2000 species, cosmopolitan.

Empididae (pushers): 3000 species, mostly found in Eurasia, North and South America.

Phoridae (humpbacks): 1000 species, mostly in the tropics.

Platypezidae (mushroom flies): 100 species, mainly in Eurasia and North America.

Pipunculidae: 400 species, mostly in the northern continents.

Syrphidae (hoverflies): 4000 species, subcosmopolitan.

Conopidae (large heads): 500 species, subcosmopolitan.

Ortalidae (spotflies): 1200 species, cosmopolitan, but especially abundant in the tropics.

THE AVERAGE LENGTH OF TWO-WINGED, MM
Buzzed
Big head
Midge
Golden eye
Hessian fly
Gadfly stomach
Bull horsefly
Sheep runny
Mosquito
Spotfly
Ktyr
Subcutaneous gadfly
Hoverfly
Hedgehog
American meromisa

Trypetidae (variegated flies): 2000 species, mainly in the tropics and subtropics.

Sciomyzidae (Tennis): 200 species, mainly in the northern continents and southeast Asia.

Drosophilidae (fruit flies): 750 species, subcosmopolitan.

Ephydridae (coastal beetles): 800 species, mainly in Eurasia and North America.

Chloropidae (cereal flies): 1200 species, cosmopolitan.

Agromyzidae (miner flies): 1000 species, cosmopolitan, but especially abundant in Eurasia.

Anthomyiidae (flower girls): 3000 species, cosmopolitan.

Calliphoridae (carrion flies): 500 species, subcosmopolitan, but mainly in the Northern Hemisphere.

Sarcophagidae (gray blowfly): 1000 species, subcosmopolitan, but mainly in the tropics.

Muscidae (real flies): 150 species, cosmopolitan.

Tachinidae (hedgehogs): 5000 species, cosmopolitan, but most diverse in the tropics.

Oestridae (nasopharyngeal gadfly): 150 species, subcosmopolitan, but mainly in warm areas.

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There are over 100,000 species of flies in the world. Some buzz, some bite, some spread disease. The most famous is the housefly - a frequent visitor to our house in warm weather. Flies can be found almost anywhere on the planet Earth. They look very different - for example, blue flies, centipedes, houseflies, midges and mosquitoes are very little alike.
The fly is one of the most common and annoying insects on Earth. Its flight delights us with its precision and gets on our nerves. And since this ubiquitous gossip has excellent eyesight and speed, it is not easy to catch it, despite the fact that it has only one pair of wings.
Flies belong to the arthropod type, the insect class, the order of flies and mosquitoes, and the fly family. The body length of a fly ranges from several millimeters (fruit fly) to 1.5 cm (housefly) and even up to 2 cm. The body length of a representative of the largest species of flies is about 7.5 cm.The fly lives from 1 to 2.5 months.

Order Diptera or Flies and mosquitoes (Diptera)

Among 33 modern orders of insects, the order of Diptera occupies one of the first places in terms of the number and diversity of representatives, second only to beetles, butterflies and hymenoptera in this respect. To date, 80,000 species are known to this order. Undoubtedly, in the near future, this figure will increase significantly, since the study of Diptera is still very far from completion.

General characteristics of the Diptera squad

In the vast order of Diptera, there is a huge variety of sizes, shapes and body colors. The length of some gall midges is only 0.4 mm with a wingspan of just over 1 mm. Some ktyri reach a length of 50 mm, and the wingspan of individual centipedes exceeds 100 mm.

Figure: 1 . General form Diptera

However, despite the large number of species and variety of Diptera, all of them are characterized by common features... Typically, adults have only one pair of membranous wings, rather thin integuments, 5-segmented legs, a licking or sucking mouth apparatus (proboscis), and well-developed compound (faceted) eyes. Development takes place with complete transformation (metamorphosis), i.e. a larva hatches from the egg, which, after several molts, turns into an immobile pupa, and an adult insect (imago) is born from the pupa. Diptera larvae, unlike caterpillars, are always legless.

Although large flocks of dipterans can often be observed, they are not social insects such as termites, bees, and ants. On the contrary, most of them live alone, at least for most of their lives. However, many Diptera gather in a kind of swarms, attracted by the smell of food, convenient place for resting or mating.

Diptera can flock to light together with other insects. Mosquitoes, bells and centipedes swarm closer to dusk, usually over bushes, paths or other landmarks, near which the swarm, if frightened off, gathers again. Such groups consist mainly of males; it is believed that the sound of their wings attracts females with its characteristic tone. In experiments, reproducing sounds similar to the squeak of female mosquitoes of certain species, it was possible to induce swarming of the corresponding males. Aggregations are especially characteristic of blood-sucking dipterans (gnats). If the species is active mainly in the dark, it is called night, if in the daytime - daytime; an intermediate twilight group is also distinguished.

Hanging flight is observed in various Diptera species, but it is especially developed in Hoverflies and buzzed. Representatives of these families fly fast and maneuver perfectly in the air. It is often possible to observe how they hover motionlessly in place, intensively working their wings, only to then suddenly disappear from the field of view.

Order Diptera, or flies and mosquitoes (Diptera) (B.M.Mamaev)

Among 33 modern orders of insects, the order of Diptera occupies one of the first places in terms of the number and diversity of representatives, second only to beetles, butterflies and hymenoptera in this respect. To date, 80,000 species are known in this order. Undoubtedly, in the near future, this figure will increase significantly, since the study of Diptera is still very far from completion.

The main features that distinguished dipterans from other orders of insects are, firstly, the preservation in the adult stage of only the first pair of wings - organs of fast and perfect flight and, secondly, the radical transformation of the larval stage, expressed in the loss of legs, and in the higher dipterans also in the reduction of the head capsule and, ultimately, in the development of extraintestinal digestion.

The body shape of adult Diptera is very diverse. Everyone knows slender long-legged mosquitoes and stocky short-bodied flies, but only experts will attribute to this order a microscopic wingless "bee louse" or a female of one of the humpback species found in anthills, which looks more like a very small cockroach.

The organs of vision - large faceted eyes - in dipterans often occupy most of the surface of their rounded head. Additionally, on the vertex there are, although not all, 2-3 punctate ocelli.

Antennae, or antennae, are located on the frontal surface of the head, between the eyes. In mosquitoes, they are long, multi-segmented, which is one of the most distinctive features that distinguish the suborder Nematocera. In flies belonging to the other two suborders, the antennae are greatly shortened and usually consist of only three short segments, the last of which bears a simple or feathery bristle. Antennas are mainly the sense organs for smells. On the surface of each of the segments there are olfactory tubercles specially adapted for this. Often the antennae of male Diptera are much more complex than those of females. These secondary sex differences are usually observed in mosquitoes; in flies, they appear more often in the size of the eyes.

The mouthparts of Diptera (Fig. 407) are strongly changed and are suitable for receiving mainly liquid food. The most perfect device for this is the proboscis of higher flies, formed by the lower lip and ending with sucking blades.

In blood-sucking mosquitoes, the mouthparts are strongly elongated, the lower lip forms a groove in which piercing stylets are located: needle-shaped upper jaws (mandibles) and lower jaws (maxilla). Between them is the hypopharynx, through which the salivary gland duct passes. From above, the groove of the lower lip is covered by the upper lip.

In some blood-sucking flies, mandibles do not develop and the proboscis is arranged differently than in mosquitoes. Their lower lip forms a stiletto-shaped solid groove, the cutout of which is covered by an upper lip of the same shape, which is linked to the lower by special outgrowths. The denticles, which in the proboscis of higher flies are located on the sucking blades and serve most species for scraping off solid food particles, are greatly enlarged in bloodsuckers and are used to open the covers of animals. At the same time, the fly puts the proboscis vertically to the skin of the animal and sets in motion the rollers on which the pre-oral teeth are located. Notching the upper protective layer skin, these teeth quickly drill out the wound. Such proboscis are possessed by flies, tsetse fly and other closely related species of Diptera. When piercing the integument of insects predatory flies - ktyryami and green tea - the main role is played by the lower lip together with the throat. In such bloodsuckers as horseflies, the wound is made mainly by mandibles.

The three thoracic segments of dipterans are tightly welded together, forming a strong thoracic region - a repository of powerful muscles. He serves reliable support for wings during fast flight. The halteres are also located here - short clavate appendages, which are a modified second pair of wings. They are considered organs of balance. The mesothorax - the most powerful thoracic segment - is provided with a semicircular outgrowth - a shield at the posterior edge from above.

At rest, the wings fold over the abdomen in a roof-like manner, horizontally one above the other, or they are simply retracted back and to the sides. Many Diptera families are best distinguished by wing venation - a pattern that forms on transparent wings by their skeleton - veins. In good flyers, the leading edge of the wing is especially firmly reinforced with veins. The surface of the wings is often covered with large and small hairs or scales, and sometimes bears additional sensory pores. At the base of the wing, many flies have pectoral and wing scales, as well as a winglet.

The leg structure of Diptera is closely related to their lifestyle. Mobile, fast-running flies have short, strong legs. Mosquitoes, on the other hand, usually hiding among vegetation during the day, have long limbs adapted for climbing among the interlacing of grass stalks or in the foliage of trees and bushes. The paws of the feet end in claws, at the base of which 2-3 special suction pads are attached. With their help Diptera can move freely on a completely smooth surface.

It has been proved by witty experiments that in flies these pads serve not only for movement, but are additional taste organs, signaling the edibility of the substrate on which the fly has landed. If a hungry fly is brought to the sugar solution so that it touches it with its paws, then the fly extends its proboscis for sucking. When the sugar solution is replaced with water, the fly does not react in this case.

Both the thorax and the abdomen, consisting of 5-9 visible segments in Diptera, often have a characteristic coloration and are covered with hairs and bristles. The arrangement of these setae is often used as a feature to distinguish between individual families, genera, and species of the order.

The idea of \u200b\u200bdipteran larvae as whitish, legless and headless "worms" swarming in manure and garbage dumps does not at all reflect the true diversity of their forms and is based on the most superficial acquaintance with the detachment.

First of all, it should be emphasized that in the larvae of all long-wattled dipterans, the head is well developed and often equipped with strong jaws, with the help of which the larvae feed on plant roots or rotting organic matter. The only exception is the rare family of long-wattled Diptera - Hyperoscelididae. In the larvae of hyperoscelidids, the head capsule is completely absent; their head segment bears only a pair of antennae and an oral opening. These larvae live in decaying wood and feed exclusively on liquid food.

The head capsule never develops in the larvae of higher flies, the entire mouth apparatus of which is usually represented by only two sclerotized hooks.

The loss of the head capsule, which is so characteristic of the larvae of higher dipterans, is associated with the development in them of a peculiar way of digestion, which is called extraintestinal... With this type of digestion, food is preliminarily digested outside the body of the larva under the influence of the digestive juices it secretes, and only then is it swallowed and absorbed.

The shape of the body of the larvae is varied. Usually it is worm-like, but sometimes it is so unusual that it can confuse an inexperienced taxonomist. Quite bizarre, for example, flat larvae living in fast mountain streams deuterophlebiid (Deuterophlebiidae) is a small family found in the Altai, Tien Shan, Himalayas and Rocky Mountains of North America. Each segment of the larvae carries a long outgrowth laterally with a sucker at the end. By alternately moving these outgrowths, the larvae are able to slowly move over the stones at the bottom of the fastest streams. Their tracheal system is completely absent - a rare case not only in dipterans, but also in insects in general, and they breathe with the help of anal gills.

Larvae are very remarkable ptichopterid (family Ptychopteridae), developing in fresh water bodies. They have a well-developed head, dense integument with dense rows of spines, and a long respiratory tube formed from the last two segments of the abdomen. There are spiracles at the end of the tube, and two respiratory filaments are attached to its middle part. The importance of the tube in the life of the larvae is clear: with its help, the larva can, without losing contact with the atmospheric air, rummage the bottom of shallow water or underwater parts of plants in search of food.

Slime-like larvae of mosquitoes of the genus are very interesting ceroplatus (Ceroplatus of the family Ceroplatidae), found openly on the surface of fungi and molds. They have a rare ability among dipterans to emit a weak phosphoric light in the dark, the source of which is their fatty body. The glow continues in the pupa, but disappears in the adult mosquito.

Perhaps the only permanent feature of Diptera larvae is the absence of thoracic (true) legs. The absence of legs in the larvae of flies is in some cases compensated by the development of various outgrowths of the body in them, reminiscent of the "false legs" of butterfly caterpillars. With the help of these outgrowths, the larvae can move relatively quickly over the surface of the substrate. Such larvae are known, for example, in the family snipe (Leptidae), numbering over 400 species. In most of them, the larvae are worm-like and outwardly do not differ from the larvae of the house fly. But in the larvae of the ibis fly (Atherix ibis), which live among stones at the bottom of fast-flowing rivers, each trunk segment has a pair of "false legs" equipped with hooks, which serve as perfect organs of movement.

In the abundant food substrate, Diptera larvae are found in large clusters. The usual places of mass development of the larvae of higher flies are decaying animal corpses, garbage dumps, latrines, etc.

The larvae of mushroom mosquitoes (Mycetophilidae) are a source of frustration for mushroom pickers. In most cases, it is their long white larvae with a black head that teems on the fractures of the "wormy" mushrooms, making them completely unusable. True, mushroom gnats cannot be considered exclusively inhabitants of fungi, some of their groups are associated with rotting wood, plant debris, etc., where they also form large colonies.

Larvae of leaf mosquitoes ( family Sciaridae). In some cases, when food is scarce, these masses of larvae can undertake mass migrations. Larvae war mosquito (Sciara militaris) are grouped in a long tape up to 10 cm, which, wriggling slowly, moves in search of a favorable place. The appearance of such "snakes" aroused superstitious fear in people, they were considered a harbinger of crop failure, war and other disasters. Hence the name of the mosquito - "military".

The process of transformation of an adult larva into a pupa in Diptera has its own characteristics. Usually in insects with complete transformation, after the pupa is formed under the covers of the larval skin, these covers are shed and the pupa is completely released.

Longwhite Diptera are no exception to this rule. But a whole group of higher flies has a special additional protective device that protects the pupa from damage and is called puparia... In this case, the skin of an adult larva is not only not discarded as an unnecessary shell, but, on the contrary, hardens, acquires a barrel-shaped shape and is strengthened by various deposits. The pupa is formed inside this skin, and an adult fly, in order to be free, breaks out a round outlet in it (Table 55).

This biological feature is the basis for the selection of Diptera in the detachment, except suborderlong-wattled, or mosquito (Nematocera), two more suborders: short-necked longitudinal dipterans (Brachycera-Orthorrhapha) without puparium, and short-tailed circular-seam Diptera (Brachycera-Cyclorrhapha) developing with puparium. Interestingly, although the larvae of some groups of Diptera do not form a typical puparium, they still pupate inside the larval skin. Among long-wattled dipterans, this method of pupation is characteristic of a small family scatopsid (Scatopsidae), numbering about 130 species, and for a few species of the family gall midge (Cecidomyiidae), such as the Hessian fly and some others. From short-mouthed longitudinal dipterans inside a slightly altered larval skin, larvae of lion cubs pupate.

The adaptability of Diptera to various living conditions is unusually wide. Their larvae have mastered a wide variety of habitats: fast streams and stagnant waters, clean, transparent bodies of water, including seas with salt water, and fetid sewage ditches, soil, various rotting plant substances that fall into the soil, tissues of living plants and, finally , the body cavity of insects and other invertebrates, as well as the intestinal tract, subcutaneous tissue and respiratory tract of vertebrates, and in some cases, humans.

Diptera larvae lead a hidden lifestyle and are incapable of long-term movements. It is the task of adult flies, which are therefore good flyers, to attach their offspring to suitable conditions. Many of them have interesting adaptations that increase the survival rate of the larvae. Suffice it to recall the birth of living larvae, widespread among the higher Diptera, and in some cases about feeding the larvae with secretions of special glands, when the larva leaves the mother's body, being already quite adult.

However, usually not adult flies feed their larvae, but, on the contrary, larvae store nutrients necessary for the life of the adult phase.

It is not uncommon for adult Diptera to live exclusively on the nutrients that the larva has accumulated and do not feed at all. For other species, it is sufficient to drink water, flower nectar, or sweet sap from injured trees. But not all adult Diptera are so harmless. Mosquitoes, horseflies, biting midges, midges, mosquitoes are annoying bloodsuckers. However, only females suck their blood, while males are completely harmless. If the females of these Diptera do not drink blood, they will remain sterile. Their bloodlust is also explained by the fact that they need to drink a lot of blood, otherwise only part of the eggs will develop in the ovaries or the supply of nutrients will not be enough at all.

One of the Diptera families - fruit flies (Drosophilidae) - forever entered the history of science, as its representatives served as one of the main objects in the study of the role of the smallest structures of the cell nucleus - chromosomes in the phenomena of heredity. And this is not accidental: under experimental conditions, Drosophila larvae develop very quickly on artificial media and after 7-10 days the results of the experiment can be evaluated. When adult flies or their larvae are exposed to X-ray or radioactive radiation, numerous changes occur in their offspring - eye pigmentation disappears, wings are underdeveloped, sometimes an ugly limb grows instead of one of the antennae, etc. In the experiment, it was possible to obtain flies that were several times larger than normal, ugly specimens were also obtained, in which one half of the body had the characteristics of a male, and the other of a female or many of the characteristics of an individual were of an intermediate character. The results of all these experiments formed the basis of many important scientific conclusions about the laws of heredity, which are being studied by genetics.

Diptera are one of the most numerous groups of insects and therefore represent a great force of nature. And this power, if we evaluate the importance of Diptera in general, causes enormous damage not only to the economy, but also to human health.

In nature, there are numerous foci of various diseases that affect wild animals. In many cases, these diseases are not dangerous to humans, but some of them pose an extremely serious threat to humans. There are also diseases that are not spread from person to person, but are nonetheless very widespread. Blood-sucking dipterans attacking animals and humans, along with other blood-sucking arthropods, spread these diseases widely, transmitting the pathogen while sucking blood.

The main danger from the malaria mosquito is not that it inflicted a painful bite, but that at the same time it can bring malaria pathogens into the bloodstream, and this disease alone has claimed many more human lives than all wars in the history of mankind put together.

Equally dangerous vectors of infections are synanthropic dipterans, that is, species that live in human dwellings. Visiting garbage and feces, they transfer pathogens and worm eggs on their body and in the intestines, leaving them on dishes, food, furniture, etc. It is not without reason that many teams of scientists are working on studying the biology of one of these insects - the housefly - with the aim of her extermination.

Diptera larvae can also be serious pests of food supplies. Great harm, for example, is caused by a nondescript cheese fly (Piophila casei), belonging to the family pyofilide (Piophilidae). Its white, shiny larvae develop in old cheese, ham, bacon, salted fish, destroying these foods. Adult larvae emerge from food and look for places to pupate in the debris of dark corners, crevices and cracks. They are sometimes called "jumpers" for their ability to curl up in a ring and sharply straighten up to jump.

Cheese fly larvae are dangerous to human health when food contaminated by them is eaten. In the human intestine, larvae are able to maintain viability for a long time, causing ulceration of the intestinal wall, with symptoms resembling typhoid fever.

The negative significance of those Diptera that attack a person during his work in the field should not be underestimated, significantly reducing labor productivity, and in some cases making this work impossible at certain periods.

The positive role of dipterans in nature and in the human economy is small compared to the harm they bring. They are tireless orderlies who cleanse the land surface of the garbage that accumulates here. Some groups of Diptera are known as soil formers and as enemies of harmful insects, which restrain their reproduction.

Diptera are very widespread: from the tropics to the boundaries of ice in the north and in the mountains. But even among the tropical representatives of the order, there are almost no especially large and brightly colored species. Insect lovers pay little attention to them, giving preference to beetles and butterflies, although biologically dipterans are no less interesting and peculiar.

Suborder Long-wattled Diptera (Nematocera)

Mosquitoes have a slender, elongated body and slender, usually long legs, less often they are dense, squat, with short legs. Their antennae have more than three segments. In larvae, the head capsule is well developed. Coated pupae.

Longleg (family Tipulidae) are those large mosquitoes that fly out from under your feet in a wet meadow or forest glades and, lazily flying several tens of meters, again hide among the grass.

Representatives of this family are distinguished by a slender body, long wings and very long, thin and weak legs, which serve them not only for climbing among vegetation, but also are a kind of protection from enemies. When the mosquito sits, its legs are wide apart, and the approaching predator grabs the long-stemmed by the legs. But it is impossible to hold these mosquitoes by the legs, their limbs immediately come off, and instead of large prey the predator has only one or two convulsively quivering legs. This method of protection is widespread in nature. Suffice it to recall the haymakers who also flee from the enemy, leaving him several of their limbs, lizards that leave only the end of their tail in the teeth of the pursuer, octopuses sacrificing their tentacles, etc.

The larvae of centipedes are inhabitants of a humid environment: soil, litter, decaying wood or fresh water. They have a large, dark, well-developed head and strong gnawing jaws. Most species feed on decaying plant debris, but some also gnaw at living plant roots.

The process of digestion of these larvae is interesting. Plant food, which consists mainly of very persistent substances - fiber and lignin, is difficult to digest. Single-celled animals come to the aid of centipedes. They multiply en masse in the intestines of the larvae, secreting enzymes that aid in the digestion of fiber. As a result, the food is enriched with substances that are absorbed by the larvae of the centipedes. Interestingly, the intestines of the larvae are equipped with special blind outgrowths, where food is retained and where especially favorable conditions are created for the reproduction of microorganisms. This type of digestion, when plant food is digested in the intestine with the participation of symbiotic microorganisms, is found not only in insects, but also in vertebrates, for example, in a horse, in which the stomach is also greatly complicated.

Among the few harmful species of centipedes worth mentioning garden centipede (Tipula paludosa) is an extremely widespread species, whose larvae gnaw at the roots of plants, including cultivated ones. There are more than 2500 species in the family.

Family retina wing (Blepharoceridae), which includes only 160 species, is famous for the originality of its larvae that live in fast mountain streams. The head of the larvae merged with the thoracic region into a single whole, as well as the end segments of the abdomen. The middle abdominal segments have six powerful suction cups of a complex structure, the sole of which is seated with strong bristles. With the help of suckers, the larvae slowly move over stones in jets of a fast stream, scraping off various growths from them.

Before pupation, the adult larva is firmly fixed on the stone, the skin on its dorsal side breaks and its scraps are quickly carried away by streams, exposing a delicate pupa. The pupa's integument soon hardens, it darkens and becomes unobtrusive.

The mosquitoes emerging from the pupae emerge from the bottom of the stream and fly to damp, shaded places, usually in crevices of rocks, where for the most part they hang calmly, clinging to the ledges with their long and thin legs.

In all zones of the globe, from the tundra to the tropics, with the exception of only sultry deserts, one of the most annoying insects in warm weather are real mosquitoes (family Culicidae). In swampy areas these insects chase animals and humans in clouds, inflicting painful injections with their long proboscis (Table 56), from which even the fabric of clothing does not protect a person if it is not thick enough. Perhaps, no other group of Diptera has such a perfect instrument of sucking blood as this stylet, which essentially consists of several stylets: two needle-shaped mandibles and two maxillae, the upper lip and the subopharynx, enclosed in a case - the lower lip. By the presence of a proboscis, it is easy to distinguish between true mosquitoes and mosquitoes-derguns, in which the mouth organs are not developed.

However, not all mosquito species are aggressive. Many of them use their proboscis only to feed on nectar. In blood-sucking species, blood saturation is also mandatory only for females, while males are content with plant juices.

The medium for the development of mosquito larvae is shallow stagnant reservoirs or micro-reservoirs - forest puddles, accumulations of water in hollows, rain barrels and even cans with rain water. Overwintered females of our common bloodsuckers from the genera Culex, Aedes, Anopheles lay their eggs here.

Common eggs anopheles mosquito (Anopheles maculipennis) swim singly on the surface of the water. After 2-3 days, larvae appear from the eggs, all further development which passes at the surface of the reservoir. Most of the time, the larvae spend in a horizontal position, attaching themselves to the surface film with non-wetting shoulder lobes, groups of special hairs on the abdominal segments and a stigmal plate; at the surface they are held by surface tension forces. In this position, the larvae feed on organic residues or small aquatic organisms that are constantly present in the stagnant water. The air necessary for breathing enters the tracheal system through the stigmal openings brought to the surface. An additional way of breathing is gas exchange through the skin and gills, two pairs of which surround the anus. Food is actively obtained by the larva. Her upper lip is equipped with brushes, the main purpose of which is to direct the flow of water with food particles to the mouth, where food is captured by a filter from the hairs of the oral apparatus. In addition to this method of feeding, the larvae are able to scrape food from plants and other objects immersed in water.

Disturbed larvae dive quickly, making sharp movements with the end of the abdomen. After stopping at the bottom or in the water column, the larvae begin to rise to the surface with their tail forward, making the same movements. In about a month, the larva molts three times and increases in length by more than 8 times. The adult larvae develop into characteristic humpbacked pupae, which also float at the surface of the water and breathe through a pair of respiratory tubes located on the dorsal side of the cephalothorax. In case of danger, however, pupae dive quickly, swinging the end of the abdomen several times, and then passively rise again to the surface.

The skin of a mature pupa bursts on the back, and through the gap, first the head with antennae appears, and then the chest of the mosquito, the wings and limbs are freed, and the mosquito, having got stronger, flies into the coastal vegetation.

In the evening, you can watch a swarm of mosquitoes: many dozens of males pound in the air, forming a kind of "singing" cloud, while females one after another fly into the swarm and immediately leave it, carrying one of the males.

In fertilized females, the blood-sucking instinct awakens. A hungry female is capable of up to 3 km locate large concentrations of warm-blooded animals and humans and quickly overcome this distance. In one act of sucking, the female absorbs an amount of blood that exceeds her original body weight. In the process of digestion of this blood due to the incoming nutrients in the ovaries of the female, the first portion of 150-200 eggs is formed. The female becomes aggressive again only after she has laid these eggs in the nearest body of water. Since that time, if the first time the female drank the blood of a person with malaria, she becomes dangerous, since her saliva is now teeming with sporozoites - the initial stage of development of malaria plasmodium.

After re-pumping blood, the female again loses interest in food until maturation and laying of the next portion of eggs. The female lives in the summer for about 2 months. By the fall, females appear, preferring to feed on nectar. At the same time, their ovaries do not develop, but reserve fatty substances accumulate in the body. These females climb into cool and empty shelters, caves, hollows, burrows, basements, where they winter. The development cycle of other types of blood-sucking mosquitoes is very similar.

From a practical point of view, it is important to distinguish human-safe mosquitoes from malaria vectors. Our ordinary mosquito squeak (Culex pipiens), an annoying but harmless bloodsucker, differs well from the malarial in its fit (Fig. 410): it keeps its body almost parallel to the surface on which it sits, while the abdomen of the malaria mosquito deviates at an angle of 30-40 °. The larvae of the squeak mosquito hang vertically near the water surface, upside down (Table 57); in the malaria mosquito, the larvae are kept horizontally.

The importance of mosquitoes as carriers of pathogens of such serious diseases as malaria in its various forms, yellow fever caused by a virus, Japanese encephalitis, encephalomyelitis, etc. Only a well-developed scientific system for the prevention of these diseases in the USSR and some other countries has dramatically reduced the incidence of people. To control mosquitoes, not only chemical but also biological control measures have been successfully applied. A small viviparous fish, imported from America, acclimatized in Central Asia, where it became one of the main enemies of mosquito larvae. It is interesting that the larvae of some harmless species of mosquitoes are predators, destroying the larvae of the bloodsucking mosquitoes. One larva toxorinchitis mosquito (Toxorhynchites splendens), common in the tropics, kills up to 150 other mosquito larvae. This species has been successfully acclimatized in some Pacific islands to control harmful mosquitoes. There are about 2000 species in the mosquito family.

Mosquitoes are the first of the five main families of blood-sucking Diptera, the complex of which is aptly named "gnus". Together with horseflies, biting midges, midges, and in the south also mosquitoes, mosquitoes form hordes of dipterans, which, especially in swampy taiga places, do not give a minute of rest in the summer months, attacking animals and humans.

This is how zoologists who have visited the taiga describe this phenomenon.

"In summer and autumn, on a bright sunny day and in cloudy weather, from morning to evening, humans and animals are besieged by myriads of mosquitoes and especially midges. Midges get into the eyes, into the mouth, stuffed into the ears and nose. It is difficult to breathe, ringing in the ears, eyes are covered with tears.Calves and foals sometimes die, seized by gnats.Large wild animals, for example, in summer make distant migrations to the mountains and to the sea, where they escape from the gnat thanks to the wind. pets stop eating and gather under a canopy, where smokers are bred to drive away the gnat.

A person takes refuge indoors, and in the open air he uses smoke, nets, ointments for his protection. But neither the room, nor the tent, nor the clothes protect against bloodsuckers: annoyingly attacking, insects pierce the tissues, climb under the clothes and into the room. In a person besieged by a gnat, drops of blood appear on the face and hands in a few minutes. You rub dozens of insects bloated with blood, hundreds of new ones sit on you.

The midges subside at night, but the mosquitoes and biting midges are still active; biting midges, due to their insignificant size, penetrate through the smallest cracks in tents, in doors and windows and attack sleeping people; their injections are especially painful. "

The most numerous are blood-sucking dipterans in the virgin, untouched taiga. With its development, the number of bloodsuckers decreases, but even large systematic measures to combat the gnat do not yet give such an effect that one can speak of the final victory over this army of enemies of animals and humans.

Extensive, numbering over 3000 species family mosquito-derguns, or bells (Chironomidae), closely related to large and small bodies of water. On quiet, warm evenings, you can hear a subtle melodic ringing over the reed-covered banks of ponds and small rivers. This ringing is emitted by swarming mosquitoes, which then suddenly soar up, then passively fall down. The bells are usually pale yellow or light green, less often dark in color, their forelimbs are strongly elongated, raised and serve as organs of touch, the mouth organs are not developed, the antennae of the males are densely feathery.

Having washed a portion of silt from the bottom of the pond on a sieve, you can almost always find the larvae of bell mosquitoes. These larvae have no need for atmospheric air: the absorption of oxygen dissolved in water, and the release of carbon dioxide occurs in them through the tracheal gills and partially through the integuments of the body. In the silt of various water bodies, including highly polluted ones, with a low oxygen content in the water, red larvae live bloodworms (Chironomus plumosus) and a number of related species. These larvae intensively feed on microorganisms that populate the silt, hiding in the cobweb tubes from their numerous enemies. They are very readily eaten by fish, for which they serve as one of the main food sources, and are well known to lovers of aquarium fish farming. In their hemolymph, the respiratory pigment hemoglobin is dissolved - a useful adaptation to life in a lack of oxygen.

In some lakes, bells' larvae descend to a depth of over 300 m, at this depth they are the only representatives of insects. In some Arctic lakes, which freeze to the bottom in winter, the larvae of these mosquitoes successfully hibernate in the thickness of the frozen silt, that is, in conditions that would be fatal for many other insects.

The larvae have adapted to living in sea water pontomies (Pontomyia natans). Females of this species have lost their wings and legs, turning into worm-like animals that do not leave the water. Males, on the other hand, seek out females by running along the surface of the water.

Borers (family Ceratopogonidae) - small mosquitoes, their body length rarely exceeds 3-4 mm... They are close to the belling mosquitoes from which they differ good development oral apparatus in adult mosquitoes. Recall that adult bell mosquitoes do not feed and their mouth organs are underdeveloped. In the family of biting midges, there are over 1000 representatives, however, only a few hundred species of bloodsuckers are well studied. Most of these species have variegated wings and, on this basis, differ well from such blood-sucking dipterans such as mosquitoes and midges.

The environment for the development of biting midge larvae can be very diverse, but always moist. Most often, larvae can be found in a layer of silt along the banks of fresh water bodies, in swampy soil, in temporary micro-reservoirs, such as puddles on roads, rainwater in the hollows of trees, biting midge larvae are not uncommon in the flowing tree sap, wet, rotten wood, etc.

Thin and long biting midge larvae of white or pinkish color with a dark brown head and a naked smooth body are able to move quickly in silt or swim in water, wriggling serpentinely. The development time of various species ranges from two weeks to two months. Pupation occurs amicably, and after 5-7 days, adult mosquitoes begin to appear from the pupae, and the males are slightly ahead of the females in terms of emergence.

Hatching biting midges usually keep near the breeding sites among grass, bushes and in tree crowns. Many species swarm in the evenings or early mornings in calm weather, and the swarm consists mainly of males. Blood-sucking biting midges often penetrate en masse into livestock premises.

Adult biting midges feed on plant sap and are often found on flowers. Only representatives of some genera, primarily of the genus Culicoides, are malignant mass bloodsuckers. Like many others blood-sucking insects, blood feeding in these species of biting midges is characteristic only of females. Biting bloodsuckers attack people, domestic and wild animals, not only warm-blooded mammals and birds, but also amphibians and reptiles. There are known cases of attacks even on other insects, most often on mosquitoes and butterflies.

Biting midlatitudes appear in May - June and, developing in several generations, reach the highest numbers in July - August. Most blood-sucking species are active in the morning and evening; on cool, cloudy days, biting midges also attack during the day.

A single blood saturation is sufficient for the full development of eggs in the female's ovaries. After laying the first batch of eggs, the females again attack the animals and, if sucking successfully, lay eggs again.

The harm from biting midges is not limited to the toxic effect of their saliva, especially severe during a massive attack. Although the role of biting midges as vectors of pathogens is not yet fully understood, it has been proven that some species of this family are intermediate hosts of filariid nematodes; Biting midges are considered one of the possible carriers of the tularemia microbe hemosporidia, as well as some viral diseases - Japanese encephalitis, equine encephalomyelitis, etc.

The most common and widespread of the blood-sucking biting midges, which is not found only in the tundra, is stinging bite (Culicoides pulicaris), giving several generations over the summer. Its larvae are found in polluted freshwater bodies.

TO family midges (Simuliidae) includes small humpback mosquitoes, the body length of which does not exceed 6 mm... They are easily distinguished from real mosquitoes by their shorter strong legs and a short proboscis. Their wings at rest fold horizontally one above the other; short antennae usually consist of 9-11 segments.

Midges are known as annoying bloodsuckers. Together with mosquitoes and biting midges, they form hordes of midges and are equally eager to attack wild animals, livestock and humans. There are especially many midges where there are fast rivers that serve as places for the development of their larvae.

Female midges are experienced divers. To lay eggs, they go down under the water, clinging to stones and plant stems. Some species of gnats, however, prefer a quieter coastal strip to lay their eggs or drop their eggs into the water while flying over a stream.

The larvae that emerged from the eggs are immediately fixed on the substrate by the posterior end of the body, where there are hooks and powerful muscles. Females lay eggs in groups, often several females in one location. Therefore, midge larvae often form large colonies in the stream bed. Under especially favorable conditions for 1 cm 2 surfaces account for up to 200 midge larvae.

The appearance of these colonies is peculiar. The fast, changeable flow of the stream rhythmically vibrates the larvae, which passively obey the streams and more resemble small aquatic plants than living things. Only periodically diminishing "fans" located near the mouth of the larvae indicate that intense life flows inside these organisms.

Fans are complex formations consisting of numerous hairs and bristles and serve to trap food. They were formed from the lateral sections of the upper lip. The food of the larvae - organic residues suspended in water or small aquatic organisms - is filtered out of the running water with a sieve and accumulates in the fans of the larvae. Then the fans contract, and the food bolt is adjusted to the mouth opening and enters the intestines. With this method of feeding, the faster the flow, the more water is filtered through the fans and the more food is captured. Therefore, midge larvae inhabit the sections of the channel with the fastest current. This is all the more necessary because midge larvae are very sensitive to a lack of oxygen and quickly die in stagnant or weakly flowing water with a high content of rotting organic residues.

It is difficult to imagine that these legless larvae can move in jets of rapid flow. However, an experienced observer will immediately notice a conical outgrowth at the front end of the larva's body, the sole of which bears rows of hooks.

The significance of this outgrowth, called the "leg" of the larva, becomes clear only when the larvae begin to crawl. In this case, the larva lubricates the nearest surface area with a sticky cobweb secret, fixes it on it with a thoracic "leg" and tightens the posterior end of the body. Having fixed the posterior end of the body on the spider web, the larva releases the thoracic "leg" and, straightening up, looks for a new site for attachment. Along the entire path of movement, the larva weaves a cobweb thread, on which it is held if it is ripped off by the current.

In case of sharp violations of the conditions of the reservoir, the larvae of some midges release a cobweb up to 2 m and for some time they hold on to it in the streams of the stream. When the regime of the reservoir is restored, they return along the cobweb to their original place.

The entire colony of larvae pupates very amicably. Before pupation, the adult larva weaves a cocoon in the form of a cap, from which the pupa sticks out. On her cephalothorax there are branched breathing tubes that provide gas exchange. Adult midges emerge from pupae in 1.5-2 weeks. Leaving the pupal skin, the midge is enveloped in an air bubble, in which it rises to the surface, and comes out of the water completely dry.

Adult midges feed only on hot sunny days, in cloudy weather, at dusk and at night they are inactive. Only females are bloodsuckers; males feed on flowers.

The short proboscis of midges with sawing mandibles and tearing maxillae is well adapted for piercing the skin of animals. It would seem that bloodsucking is the most natural way of feeding for all midges. However, this is not the case. In some localities, despite the significant abundance of midges, they do not attack animals and humans. Special experiments have shown that female midges can successfully feed on flowers, while the eggs in their ovaries mature normally.

The activity of adult bloodsuckers also differs in different zones of their distribution: it decreases from north to south. So, broad-legged midge (Eusimulium latipes), decorated midge (Odagmia ornata), creeping midge (Simulium repens) are a scourge of humans and animals in the tundra, and to the south, in the forest-steppe and steppe zones, they are not at all registered as bloodsuckers. It is likely that the need for blood feeding arises in adult midges if their larvae developed in unfavorable conditions and did not accumulate sufficient reserves of nutrients. Among the midges, however, there are species for which bloodsucking is a necessary stage in the life cycle. It is these species that pose the greatest danger.

A midge injection is a whole surgical operation. At the time of the injection, saliva containing anesthetic substances is injected into the wound. Therefore, the pain quickly disappears and appears again only after the midge has sucked blood and flew away. At the same time, substances that prevent blood clotting are injected into the wound.

The saliva of the midges is poisonous. At the injection site, edema develops within a few minutes, burning and itching appear. With numerous bites, the body temperature rises, signs of general poisoning appear, hemorrhages and swelling of internal organs begin, which can lead to a rapid death.

The scourge of animal husbandry in the Danube countries is columbus midge (Simulium columbaczense). The larvae of this species develop in large rivers and are especially numerous in the Danube. The larvae of the Columbac midge pupate in the first half of May, and by the end of this month, the coastal bushes are covered with swarms of emerged mosquitoes. After fertilization, the males die, and the females fly away from the coast by 5-20 km in swarms and attack the livestock. In some years tens of thousands of head of livestock died from this midge.

In the USSR, bloodsucking midges are most diverse in the taiga zone. The most vicious bloodsuckers here are tundra midge (Schoenbaueria pusilla), kholodkovsky midge (Gnus cholodkovskii), decorated midge (Odagmia ornata) and a number of other species. These midges attack at temperatures from 6 to 23 ° C, and in the fall, Kholodkovsky's midge is active even after snow falls.

The harm from midges is aggravated by the fact that they are carriers of such serious diseases as anthrax, glanders, tularemia, plague, and leprosy. The causative agents of these diseases are transmitted by a female who has interrupted food on a sick animal, with a quick attack on a healthy one. In Africa, midges carry human philaridosis.

Butterflies (family Psychodidae) are very peculiar small mosquitoes, characterized by a densely hairy body and wide shaggy wings with a dense network of longitudinal veins.

In damp and dark rooms, harmless common butterfly (Psychoda phalaenoides), reaching far north.

The southern relatives of butterflies are not so harmless - mosquitoes (Phlebotomus), common in the tropics and subtropics, and in the USSR found in Central Asia. Already starting in April, female mosquitoes, like female mosquitoes, at dusk leave their daytime shelters and attack various mammals, birds, reptiles, delivering many difficult minutes to people. Feeding blood is absolutely necessary for females, otherwise they will not leave offspring. The nectar of flowers, although it is used as food by mosquitoes, fully provides only males, while females of mosquitoes are distinguished by a special bloodthirstiness. Having sucked in blood, females begin to digest it. At the same time, the maturation of eggs in the ovaries begins.

Unlike mosquitoes, mosquitoes are not associated with water. Their larvae develop in various organic residues, however, at a sufficiently high humidity. In settlements, the places of development of mosquitoes are spaces under the floor, garbage pits, latrines, stockyards, in nature - caves, hollows, damp pits and, especially in desert areas, burrows of turtles and rodents. The duration of development of one generation of mosquitoes is about 2 months.

A person should carefully guard against the bites of these small insects. With their saliva, pathogens of serious diseases - the papatachi fever virus, as well as leishmania, which cause visceral and cutaneous leishmaniasis-pendin ulcer - can be brought into the blood. Visceral leishmaniasis is especially dangerous, in which the internal organs of a person are affected - the liver, spleen, bone marrow.

Gall midges (Cecidomyiidae) - family Diptera, numbering over 3000 species. These include small mosquitoes, mostly orange in color, with long antennae and legs and very weak wings, reinforced with only 3-4 longitudinal veins. Adult gall midges do not feed and live only 2-3 days, therefore the prosperity of this family is explained by many useful gadgetsthat have developed in their larvae.

The smaller the insect, the more enemies it has. But the larvae of gall midges, which can be examined in detail only through a magnifying glass, are not afraid of enemies - they are reliably hidden inside the gall from both predators and the adverse effects of the external environment.

Gallus - abnormally altered parts of organs, and sometimes entire plant organs (flowers, fruits, shoots, leaves), transformed by larvae into a more or less closed chamber (Table 58). In such a chamber, the larvae have nutritious food - vegetable juice, they are not afraid of the vicissitudes of the weather - the walls of the gall reliably isolate them from adverse influences.

The formation of a gall is very complicated. The gall midge larvae do not gnaw the tissue of the plant; their tiny head and piercing mouth parts are unsuitable for this. The larva acts differently: it releases specific growth substances on the surrounding tissues, under the influence of which the plant cells begin to grow and divide rapidly. As a result of the close and precise interaction of the larva and the plant, a gall of a strictly defined characteristic shape is formed, so that the type of gall midge can be easily determined by the shape of the gall. Adult larvae sometimes pupate in the gall, sometimes fall into the soil, where they weave a silky cocoon.

Inside the cocoon, the larva quickly turns into a pupa. Adult gall midges emerging from pupae must find a plant suitable for the development of larvae. There are a lot of phytophagous gall midges, but each type of them is strictly confined to a certain type of plant. If the female is mistaken, the larvae that emerged from the eggs will not be able to form a gall on an alien plant and will die. But such errors are very rare, since gall midges distinguish plants very accurately, being guided by the subtle features of their smells.

Many species of gall midges are common and very widespread. In the forests on the petioles of aspen leaves, reddish rounded galls are found in summer aspen stalked gall midge (Syndiplosis petioli, pl. 58, 2). The tops of willow shoots are transformed into a characteristic gall, resembling a rose flower in structure, larvae willow rose-forming gall midge (Rhabdophaga rosaria, pl. 58.5). The Gauls caused by saxaul gall midges in the deserts are especially diverse.

Gall midges reproduce periodically in incredible numbers. Species that damage cultivated plants are especially dangerous during periods of mass reproduction. In Europe, Asia and North America, common hessian fly (Mayetiola destructor) - the scourge of grain breads. The females of this gall midge lay their eggs on the leaves of seedlings of wheat, rye or barley. The larvae develop in the leaf sheaths, damaging the stem so much that it breaks off from the wind. The fields affected by the Hessian appear to have been trampled by cattle.

However, not all groups of gall midges develop in plant tissues. The primitive gall midges still retained a strong connection with their primary habitat — soil, litter, and decaying wood. Especially noteworthy are the gall midges of the genus living in decaying plant debris and wood miastor with a single view - Miastor metraloas. Larval colonies of this species number thousands of specimens (Tables 58, 12), and each colony originated from one egg. Miastor has a rare ability among insects to reproduce at the larval stage. As soon as the larva of this species reaches maturity, numerous daughter larvae quickly form inside it, which, eating the insides of their parent, break the wall of her body and go outside. They eventually suffer the same fate, and the colony of larvae grows rapidly. Only after multiplying strongly, all the larvae of the colony finally pupate together, and the adult gall midges scatter in search of new habitats.

This rare method of reproduction, first studied by N. Wagner in these gall midges, was called pedogenesis. Further pedogenesis in the class of insects was also discovered in one of the North American beetles.

Family thickened (Bibionidae) includes about 400 species, the value of which in nature lies in the active processing of organic matter entering the soil and improving the properties of the soil. This processing is carried out by large, up to 1.5 cm, gray larvae with a large head, strong jaws and numerous fleshy outgrowths on the body. The larvae live in separate colonies, each of which is the offspring of one female, who laid the entire stock of her eggs in a given place. Only some Dilophus feed on live plants, the larvae of which gnaw at the roots.

Adults appear very amicably during the warm spring months. They often accumulate in mass on flowers, grass, leaves of shrubs, or fly lazily in the sun. The eyes of the fat-pegs are peculiar. In males, each eye is divided into two parts, and the facets in the upper half are much larger than in the lower. Usually the eyes are densely covered with hairs. Antennae short, 9-12 segments. The tibiae of the forelegs are thickened and spiked. Often, males and females differ in color. Have garden skeins (Bibio hortulanus) the male is black, the female is reddish-brown, but her head, shield and legs are black.

Expressive appearance of sluggish, awkward, brilliantly black or brown mosquitoes from families aximid (Axymyiidae) recalls those distant times when Diptera were still in their infancy.

Indeed, many of the structural features of these mosquitoes are inherited from their distant ancestors. First of all, attention is drawn to their wings, adapted to slow and heavy flight, sluggish, clumsy legs, and the whole appearance of an insect, unable to fly away quickly, or run away, or in any other way to protect itself from enemies. Only the eyes of these mosquitoes have reached a high degree of perfection: they occupy almost the entire surface of the head, and in males, each of them consists of two sections - the upper, from large facets, and the lower, from smaller facets. The mouth parts of mosquitoes are reduced, and the antennae are greatly shortened, but they have a large number of short segments, which range from 13 to 17.

How did such helpless insects survive to this day? This became possible because the almost complete defenselessness of adult mosquitoes was compensated by the development of very perfect adaptations in their larvae, which passed on to life in wet rotten wood. They have a large head and strong jaws, with which they grind short strokes. Their thick, whitish body ends with a long respiratory tube, at the base of which 2-4 bead-like outgrowths are attached with a dense plexus of trachea inside. All this is a complex breathing apparatus in wood saturated with water. Other insects have not been able to adapt to life in such an environment, and therefore aximids have very few enemies and competitors. But even under these conditions, only 4 species of this family have survived to the present time, common only in the northern hemisphere.

Relatively recently, in 1935, when it seemed that all families of Diptera were already known, a description of a strange mosquito found in the mountains of Japan was published. This find immediately attracted the attention of scientists, since the described insect could not be included in any of the known families of the order. So the first information about the new family nymphomyid (Nymphomyiidae), representatives of which were also recently discovered in North America.

White nymphomy (Nymphomyia alba) differs from other Diptera primarily by its large elongated-triangular wings with very weak venation. The anterior and especially the posterior margin of the wings are covered with dense rows of very long hairs, increasing the total wing area. The head of the mosquito is directed straight ahead, the underdeveloped eyes merge not from the upper, but from the lower side, the mouthparts are underdeveloped, and the antennae consist of only 3 segments with a small appendage at the end.

Even more amazing is the pupa of the white nymphomy, which has a free movable head. The only thing known about the larvae of this amazing mosquito is that they live along the banks of mountain streams. This was established because insect pupae were found there, but no one has ever seen the larvae themselves.

Among the modern Diptera, there were no forms with which the nymphomyids could be brought together. They cannot be rightfully considered long-wattled dipterans, since their antennae consist of only 3 segments. They also differ sharply from short-tied. Only from the Upper Triassic deposits, studied in Central Asia, are known dipteran fossils with a similar structure. When the larvae of the nymphomyids are studied, it may be possible to answer the question of which modern Diptera are their closest relatives. In the meantime, this family occupies a separate position in the Diptera order.

Suborder Short-tailed longitudinal dipterans (Brachycera-Orth0rrhapha)

They are typical flies with a compact, short body and wide, strong wings. Their antennae consist of 3 segments, but the last of them may retain traces of additional dissection. The head capsule of the larvae is strongly reduced. The larval skin is usually discarded during pupation. The pupa is covered; when the fly leaves, its goth lobothorax cracks along the T-shaped line.

Blind (family Tabanidae) are large blood-sucking dipterans. A horsefly female is capable of taking up to 200 mg of blood in one sucking blood, that is, as much as 70 mosquitoes or 4000 biting midges drink. If we add to this that in marshy areas during the hot summer months, herds of domestic animals attack tens of thousands of horseflies, the enormous negative significance of horseflies in human nature and economy becomes clear. Their harmfulness is further aggravated by the fact that at the time of bloodsucking, horseflies carry the pathogens of anthrax, tularemia, poliomyelitis and other serious diseases, and also transmit some diseases caused by nematodes.

Livestock losses from horseflies are great. Often the most productive pastures on the shores of lakes and in river valleys are empty during the summer months, since they cannot be used due to the abundance of bloodsuckers. Even with a moderate attack of horseflies, cows reduce milk yield by 10-15% and quickly lose weight. Scientists have calculated that in a day, the loss of strength by animals that are disturbed by horseflies and flies is equivalent to 400 r oats on the head of cattle. And this is understandable, since the largest horseflies reach a length of 2-3 cm, their bites are extremely painful and are accompanied by swelling, which is caused by saliva entering the wound during bloodsucking.

Blindflies are sometimes incorrectly called gadflies. However, it is enough to make sure that a fly caught on an animal has a short piercing proboscis to be confidently attributed to horseflies. The large eyes of horseflies are beautiful - golden, iridescent with all the colors of the rainbow. Their wings are sometimes transparent, sometimes with smoky spots, the abdomen is always flattened.

The life cycle of horseflies has much in common with the basic features of the life cycle of other bloodsuckers. Males feed exclusively on the nectar of flowers and the sugary secretions of aphids, scale insects, scale insects, as well as sweet juice flowing from wounded trees.

Unfertilized females also follow the same diet, but after fertilization there is no limit to their aggressiveness. They attack animals and humans on hot days from morning until sunset; puffball horseflies are active even in cloudy weather, especially before rain. Among their victims, large animals are in the first place: deer, elk, roe deer and especially livestock. Horseflies are also capable of attacking small animals - rodents, birds, especially fledgling chicks, and even lizards - monitor lizards, takyr round-headed heads, etc. They do not even neglect the corpses of animals in the first 2-3 days after death, which makes horseflies especially dangerous carriers infections.

At close distances, horseflies are guided by vision and perceive the contours and movement of objects. They often make mistakes and chase moving cars, boats, steamers for a long time, even flying into train cars.

Horseflies are usually not very selective about food. However, in complex plant communities, for example, in multi-tiered tropical forests, individual complexes of species are found mainly in one particular vegetation layer. In the humid forests of Cameroon, for example, ethiopian specklers (Chrysops silvacea, Ch. Centuriones) keep in tree crowns and chase herds of monkeys.

Females who have sucked blood quickly digest it. After 24 hours, the blood clot in the stomach is significantly reduced, and the absorbed nutrients go to feed the gradually increasing ovaries. After 48 hours, only a small amount of semi-digested blood remains in the intestines, and the maturing egg cells grow strongly. After 76 hours, digestion ends, the eggs finally ripen. Thus, oviposition takes place on average 3-4 days after sucking. As a result of repeated bloodsucking, females of horseflies can perform up to five such cycles, laying in total over 3500 eggs. The fertility of different horsefly species can, however, vary greatly.

Eggs are laid on plants, usually above the water of lakes and swamps. The larvae that hatch from the eggs fall into the water and live in the moss cover, root plexuses or in the upper layers of moist soil, in some species they feed on decaying plant debris, in others they are actively predatory. Among their victims are larvae of other insects, amphipods, earthworms.

Bovine horsefly (Tabanus bovinus) is one of the largest species. It is dark brown, thorax with dark stripes and yellowish hairs, the abdomen is bordered with a yellow-brown border with a strip of light triangular spots in the middle part.

The smaller one is brightly colored common gold-eyed (Chrysops caecutiens), indeed having bright emerald-gold eyes. The abdomen of this species has yellow spots at the base. More modestly colored ordinary raincoat (Chrysozona pluvialis), whose wings are distinguished by a complex smoky pattern. There are over 3500 species in the horsefly family.

Long-proboscis (Nemestrinidae) - small family Diptera, distributed mainly in tropical and subtropical areas. Adult flies resemble horseflies, but they are well distinguished from them by a strongly elongated proboscis, which is usually much longer than the body. With its help, flies suck the nectar of flowers. However, it is not so easy for long-proboscis to get to the nectar - their proboscis does not bend, and the fly, especially in windy weather, has to work hard to satisfy its hunger.

North American females trichopsideae (Trichopsidea clausa) lay their eggs in cracked tree trunks or telegraph poles. The fecundity of females is very high - several thousand eggs, and this is understandable, since the original larvae that emerged from the eggs, equipped with numerous outgrowths, are simply carried in different directions by the wind. Meeting with the host, which is the locust, largely depends on chance, so most of the larvae die without reaching the goal. But if this encounter occurs, the larva enters the locust body through one of the spiracles and, feeding on host tissues, finishes development by autumn and hibernates. Adult flies appear in spring.

In total, about 250 species are known in the long-proboscis family.

Large family lioness (Stratiomyiidae), which includes about 2000 species, is distributed mainly in the humid tropics. In the northern forests of Eurasia, only about a hundred species are found.

It is easy to distinguish lion cubs by their wide, flattened body, usually painted in bright colors, often with a metallic sheen, by short transparent wings and peculiar antennae, which have an annular last segment.

This is exactly what common lioness (Stratiomyia chamaeleon), which is often found on flowers. Its black abdomen with yellow spots, brown chest with a yellow shield and red-yellow legs harmonize well with the bright color of the flower corollas, hiding the insect from enemies.

The larva of this fly is peculiar, living in shallow polluted water bodies. Its fusiform body, reaching a length of 20 mm, ends with a long "tail", which is formed from several elongated last segments of the abdomen. At the end of the "tail" there is a stigmal plate with two breathing holes. There is also a corolla of long non-wetting hairs. The larva breathes, hanging by the rear end of the body to the surface of the water. In this case, non-wetting hairs straighten, stigmas open, and the larva itself is passively held by surface tension forces. Having breathed, the larva bends sharply, breaking away from the surface film. At the same time, the hairs fold and cover the stigmal area. Then the larva slowly sinks to the bottom, where it digs among the silt and algae, swallowing decaying organic matter. The pupa forms inside the skin of an adult larva.

Many species of lion cubs develop in soil, manure, and decaying wood. Among them, metallic green or blue are especially peculiar. geosargus (Geosargus), whose larvae are common in manure. The covers of the larvae are saturated with calcium carbonate and serve as good protection for both the larva and the pupa, which forms inside the larval skin.

About 5000 species families ktyry (Asilidae) - mainly inhabitants of open spaces - steppes and deserts. These slender flies, whose body is covered with dense short pubescence, usually bask in the sun, ready to take off instantly when danger appears or in pursuit of prey. Everything in their appearance speaks of adaptation to predation. The acuity of the protruding eyes, deeply separated by the crown, is so great that it is difficult to approach the seated knots unnoticed. Although mandibles are absent in their proboscis, other parts of the oral apparatus - maxilla, hypopharynx, and lower lip - form a very perfect piercing organ. Ktyk saliva contains a strong poison, from which insects die instantly. A ktyr caught with a hand sometimes bites a person. Such a sting is as painful as the sting of a bee sting.

The quickness and infallibility of the reaction of the ktyry is surprising: a moment, a short take-off, and the lifeless insect is already being sucked out by the ktyry that has returned to its original place. The aggressiveness of the whales is so great that they emerge victorious in a battle with such well-armed insects as bees, wasps, horse beetles; the extraordinary gluttony of these flies makes them hunt continuously.

Worm larvae are also predators. In the soil, they pursue the larvae of other insects, and can withstand prolonged starvation. But in case of a successful hunt, they grow very quickly.

The larvae are peculiar lyaphry (Laphria), chasing the larvae of longhorn beetles or lamellar beetles in the wood. Their body bears numerous outgrowths that help the larva move in the passages. Adult Lyafrias sit on the bark of trees. Sometimes they are painted in bright colors, such as golden red lyafria (L. flava).

Large ktyri reach a length of 4-5 cm... Such is giant knuckle (Satanas gigas) found in the steppes.

Among Diptera, there are few other groups whose representatives could compare in speed and dexterity with flies from families buzzed (Bombyliidae). The appearance of most buzzed is very peculiar: a short, stocky body covered with long thick hairs, wings, at rest directed to the sides and back, resembling the position of the wings of high-speed aircraft, and, finally, a needle-shaped proboscis, which in some species is not inferior to the length of the body.

The proboscis is an excellent device for sucking nectar from flowers with a deep corolla, which are inaccessible to many insects. But the buzzers would not have been able to take advantage of this advantage if they had not been excellent flyers. With amazing dexterity, feeding flies literally hang in the air above the flowers, plunging the proboscis into the nectaries at this time, and, without sitting on the flower, suck the nectar.

In the modern fauna, the buzzing family is among the thriving and has about 3,000 species in its composition.

Predators are like adult flies families pushers (Empididae) and their larvae that live in the soil. The nectar of flowers, on which adult flies are often found, serves as an additional source of food for them. The long, needle-shaped proboscis of the pusher is equally well suited for sucking out insects and for absorbing plant juices. The prey - small dipterans - is captured by the front legs, the thighs of which are set with thorns, and the legs are tightly attached to them, forming strong forceps.

A disproportionately small round head and slightly pubescent body complement the characteristic appearance of representatives of this family. But the "dances" of the pushers are especially peculiar during the mating flight. They are not only quite complex in their execution, but are also remarkable for the fact that males drag along silky "parachutes" or ellipsoidal "balloons" with foamy walls, inside which lies dead prey - a small fly or a mosquito. Before mating, the male offers this prey to the female and thus saves his own life, since aggressive females often eat the males after copulation. Such "dances" are observed among representatives of the most common genera - empis (Empis), gilara (Hilara) c dr.

Green flies (family Dolichopodidae) - metallic shiny or grayish small dipterans with long legs and laterally compressed body. In total, the family includes more than 3500 species. Greenfinches are not uncommon in damp meadows, along the banks of ponds and rivers, but they are difficult to notice against the background of green parts of plants. They attack small mosquitoes and midges, killing them with a proboscis consisting of pointed appendages of the lower lip and spines of the pharyngeal cavity; mandibles in these dipterans are not developed.

Most closely related to water greenfinches-water striders (Hydrophorus), gliding along its surface like water bugs. They prey on small insects that often stick to the surface of the water. Their larvae, like most other species of greenfinches, predate in moist soil.

Useful greenfinches-medeters (Medetera), whose larvae kill bark beetles in their passages under the bark of trees. Grayish adult flies are often seen on tree trunks.

Suborder Short-tailed circular-seam Diptera (Brachycera-Cyclorrhapha)

Typical flies with a short, compact body and wide, strong wings. Their antennae are shortened, 3-segmented, with a seta on the third segment. The head capsule of the larvae is completely reduced, only the oral hooks are preserved. During pupation, the larval skin is not discarded, it acquires a barrel-shaped shape and hardens, soaked in special secretions, forming a false cocoon - puparium. The pupa is free. When an adult fly emerges, the puparium opens in a rounded line under pressure from the head or the frontal bladder, which in most cases is well developed.

Gorbatki(family Phoridae) are very small nondescript flies with a swollen, humped chest, strong legs, the thighs of which are thickened. The transparent wings are reinforced along the anterior margin by two thick, contiguous veins; other veins of the wing are much thinner; there are no cross veins in the wing.

Representatives of the genus are found in anthills platform (Platyphora). The winged male of these flies retains all the features of the family, while the female is wingless, her body is flattened like that of a cockroach, outwardly she does not in any way resemble a fly.

In termite mounds, peculiar termites (Termitoxenia, Termitomyia), which sometimes stand out in a special family Termitoxeniidae. They have a soft elongated body, an elongated head with a piercing proboscis, short antennae, and tenacious legs (Fig. 420: 3). The wings are represented by small stumps, for which termites usually drag them; the abdomen is soft, unusually swollen.

On the flowers of Umbelliferae and Compositae, flies very similar to them often sit next to wasps and bumblebees from families hoverfly (Syrphidae, pl. 59). Although these flies are completely harmless, the birds do not dare to touch them, mistaking them for the Hymenoptera armed with a sting. There are about 4500 species in the hoverfly family.

The flight of these flies is original. Along with ordinary flights, hoverflies can hang in the air for a long time, continuously working their wings, but not moving from their place. The study of such a "standing" flight has shown that only when the wing is lowered, its plane is directed horizontally - the lifting force arising in this case balances the weight of the insect. In the down position, the wing rotates 45 ° and returns upward, cutting the air with its sharp leading edge. Naturally, no translational force arises in this case.

The lifestyle of hoverfly larvae is unusually diverse, in contrast to adult flies, which part with nectar-bearing flowers only to lay eggs in a suitable place. For this, females of some species fly to dirty, fetid streams, others rush under the forest canopy, looking for trees with fermenting sap flowing from wounds, others look for colonies of aphids or bumblebee nests, still others bustle around anthills, etc.

Of the larvae of sirphids developing in water, the larva is especially notable common bee (Eristalis tenax), which is figuratively called "rat". The body of this larva is barrel-shaped, indistinctly segmented, with outgrowths - "false legs" - on the ventral surface. The last three segments of the abdomen form a characteristic "tail" - the respiratory tube. These segments are thin, and each subsequent one can be drawn into the previous one or, conversely, quickly move out of it. At the end of this device there are two spiracles, and two thick trachea pass inside the tube. The fully extended respiratory tube of adult larvae reaches a length of 12-15 cm (Fig. 421, 5).

Figure: 421. Hover flies: 1 - conosyrphus (Conosyrphus volucellum); 2 - decorated spherophoria (Sphaerophoria scripta); 3 - bakha (Baccha elongata); 4 - chrysotoxum (Chrysotoxum festivum); 5 - "rat" - the larva of the common bee (Eristalis tenax); 6 - wasp hoverfly larva (Temnostoma vespiforme)

Its significance in the life of the larvae becomes clear if you move the bottom of the reservoir in which they live with a stick. From there, silt, undecomposed organic matter will rise and bubbles of fetid gases will appear. Meanwhile, the bee larva boldly sinks into this rotting mess, where it finds abundant nutrition - after all, on the surface of the water it leaves the end of the respiratory tube through which gas exchange takes place. When the larva dives into deeper layers, it is forced after a while to rise to the surface for breathing. The larva pupates in the soil next to the reservoir. The pupa forms inside the larval skin. An adult fly with a brownish chest and a yellow-black spotted belly closely resembles a bee (Table 59, 2). It was on this similarity that the assertion, which arose in the early stages of the development of science, was based that bees can arise from mud. Now such a statement can only bring a smile.

Adult hoverflies from the genus are very similar to wasps darkstoma (Temnostoma). Their larvae are active destroyers of wood of wet stumps and dead trunks. How can these larvae of higher dipterans, which are known to be devoid of a head capsule and gnawing jaws, can grind holes in wood? For this, the larvae turned out to have completely unexpected adaptations: the bases of their prothoracic spiracles increased greatly, partially separated and turned into two powerful scrapers, the edges of which are set in rows of teeth. They scrape wood in the same way as a mollusk - a ship worm - uses the remains of its underdeveloped shell for the same purposes.

However, the most common of the hoverflies are species inhabiting aphid colonies. It is difficult to imagine that the greenish or gray larvae crawling in aphid colonies, resembling small leeches, belong to the same family as the "rat", but this is so. It is enough to look at adult hoverflies from the genus sirfs (Syrphus). Their appearance is quite typical: a dark chest with a metallic sheen and the same abdomen, on each segment of which there are two crescent spots.

The larvae of our common sirphs (Syrphus balteatus, S. ribesii) are serious enemies of the cabbage aphid (Tables 59, 16). One adult larva sucks over 200 aphids in just a day. Considering that the feeding period lasts about 20 days, it can be calculated that each larva will destroy up to 2000 specimens of pests during this time, and there are several hundred such larvae in the offspring of only one female. By attracting sirphids to fields by sowing nectar-bearing flowers, you can successfully fight many harmful species of aphids.

Hoverfly larvae of the genus microdon (Microdon), living in anthills, were initially mistaken for molluscs and described as a special genus of these invertebrates. This error is not accidental: the larva has a rounded body with a flat bottom surface without any traces of articulation and even some semblance of a shell, which is formed by its hemispherical hardened outer integument, bearing layers of dust and dirt. However, from these larvae, bronze-green flies eventually emerge, the belonging of which to hoverflies is not in doubt.

The greatest success in imitating the malignant hymenoptera was achieved by various species bumblebee, or furry (Volucella), which are similar to bumblebees both in body shape and in the arrangement of dense fluffy hairs, colored, like in bumblebees, in different colors (Table 59, 8). This similarity arose, in all likelihood, because hairs are biologically closely related to bumblebees. Their larvae develop in the nests of bumblebees, feeding on the corpses of dead larvae or always available excrement and waste.

It is difficult to imagine that the sticky resin flowing from wounded spruces can hide living larvae in itself. But the hoverflies have adapted to this habitat. Larvae black chylosia (Chilosia morio) develop only in resin. The whitish body of these larvae is immersed in its thickness, and a short respiratory tube is brought to the surface, providing an unhindered flow of air. In spring, also without leaving the resin, these larvae pupate in a kind of puparia. The completely black hoverflies that have flown out lay their eggs in wounds with fresh resin.

Other interesting example imitations of stinging hymenoptera are found by representatives families big-headed (Conopidae), numbering over 600 species. The abdomen of adult flies is slender, weakly stalked, slightly curved downwards - signs that make the fly-headed flies resemble wasps. The head of the flies is very large, the antennae are often elongated; proboscis long, slender, with one or two geniculate bends; body colored in black, brown and yellow tones.

One of the largest species of the family - yellow-footed bighead (Conops flavipes), up to 15 mm... Its body is black, the head is yellow-spotted, there are also 2-3 yellow bands on the abdomen.

Cereal flies (family Chloropidae) have become notorious as pests of grain crops, no less dangerous than the Hessian fly. Almost all members of this vast family of over 1,300 species develop on wild and cultivated grasses. Adult flies are common in meadows, forest glades, on the boundaries of agricultural fields, where they can be collected in large numbers with an ordinary butterfly net. The sizes of cereal flies do not exceed 3-5 mm, body naked, shiny black, yellow or greenish; in many species the breast is dorsally with longitudinal dark stripes on a yellow background.

Larvae damage the apical part of the stem of cereals, resulting in a characteristic spindle-shaped accumulation of leaves. As a result, the plant either dies off or begins to bush, developing weak adventitious stems.

Most species of cereal flies are food selective; each of them successfully develops on a few strictly defined plant species. The most economically important species of this family, although they are also found on wild cereals, give a clear preference to cultivated ones.

One of the most dangerous pests of grain crops is swedish fly (Oscinella frit). New studies of these flies, however, suggest that this is not one species, but a whole complex of species, each of which prefers one of the crops - wheat (O. vastator), barley (O. pusilla) or oats (O. frit ).

Damage to cultivated grasses by the fry fly varies well depending on the time of oviposition. If the attack of the pest coincides with the tillering phase of spring crops, then the larva lives under the leaf sheaths at the ear bud, which is destroyed. When the next generation of Swedes flies, the bread is already earing. In this case, eggs are laid directly on the ear and the larvae eat up the grains.

Another harmful species from this family is green-eyed (Chlorops pumilionis) is a yellow fly with black stripes on the chest. In the spring, it most often affects spring wheat and barley, and in the fall - the seedlings of winter wheat and winter rye. The green-eye larva lives under the leaf sheaths, causing shortening and thickening of internodes.

Variegated wings (family Trypetidae) are small or medium-sized flies with a peculiar pattern on the wings characteristic of each species. The pattern is made either with dark stripes and spots on the transparent wings, or a certain amount of light spots appears against the general dark background. The abdomen is often spotted. In total, about 2500 species are known in the family.

Adult flies feed on the nectar of flowers or the secretions of aphids. Their larvae are typical phytophages, that is, they feed on living tissues of plants. Many species of variegated flies have adapted to the development of Compositae plants inside the baskets, where they eat out the ovaries of flowers and receptacles. By breaking the large baskets of burdock (Arctium), you can very often find dirty white larvae eagles (Orellia tussilaginis). The larvae of variegated flies are also found in the juicy fruits of cherries, barberries and other plants.

Cherry fly (Rhagoletis cerasi) brown-black with a yellow head and shield; legs, except for the thighs, are also yellow. Females lay eggs under the skin of ripening cherries, the larvae feed on the pulp of the fruit, causing them to rot and fall off.

Some species of variegated wings enter into more complex relationships with plants, causing the formation of pathological growths - galls.

In all cases, representatives of this family have a well-expressed food selectivity - individual species of the family are able to develop not on any, but only on strictly defined plant species.

Biologically extremely interesting miner flies (family Agromyzidae). Representatives of this relatively large family, which includes 1000 species, develop in living plant tissues like variegated flies. As in the case of variegated flies, the nature of damage inflicted by larvae of miner flies is varied. The family includes gall-forming species, there are species - inhabitants of inflorescences of Compositae or their seeds, pests of grass stems and even species that have moved to habitat in the trunks and branches of trees. But the greatest flourishing is achieved by species-miners, the larvae of which eat up vast slit-like cavities in the parenchyma of leaves, called "mines".

Most miner flies are characterized not only by the damaged plant species, but also by the shape of the mine, which is sometimes so specific that it makes it possible to accurately determine the type of pest. It is interesting to note that representatives of this family have adapted to life on almost all groups of plants - from primitive ferns and horsetails to the historically youngest Compositae.

Some species of miner flies that have switched to feeding on cultivated plants have established themselves as serious pests. Harmful to cabbage and other crucifers phytomize (Phytomyza atricornis), which, unlike most species of the family, is distinguished by a significant indifference to food. About 300 species of plants from 30 different families are known, on which the larvae of this fly were found. The appearance of adult specimens is typical for the family: body length - 2-3 mm, the back is brilliantly black, the legs and breast-flanks are yellow.

In some places in the forest zone, woody miners from the genus disigomisa (Dizygomyza) associated with tree species. Willows, birches and some fruit trees especially suffer from them.

Family coastal (Ephydridae), which includes more than 1000 species, flourishes in the forest zone. These very small, nondescript flies, painted in gray and black tones, are remarkable for their biology.

The way the larvae feed is completely unusual oil psilopes (Psilopa petrolei), found in California oil springs. Numerous bacteria have been found in the oil, as well as in the intestines of the larvae, which are capable of decomposing paraffin and are believed to provide food for the larva. So far, however, it is not clear how the larvae obtain the nitrogenous substances necessary for the synthesis of proteins.

The harmful species of the family include barley bank (Hydrellia griseola). The larvae of this small gray fly with transparent wings develop in mines on the leaves of cereals, including barley, wheat and rice, and sometimes cause significant harm.

Dung flies (family Scatophagidae) got their name because their most abundant species are common on animal excrement, i.e., they are coprobionts. This is red dung (Scatophaga stercoraria) - large fly, up to 10 mm, yellow-brown in color with thick rusty-yellow hairs and slightly lighter wings of the same shade (Table 60, 8). Its larvae prey on manure and feces.

However, paradoxically, most of the species of dung flies are not associated with dung. Particularly interesting among them are plant pests, the larvae of which, like the larvae of miner flies, develop in leaf mines or live in the generative organs of plants.

Spikes of wild and cultivated cereals (rye, timothy) are pests of spikefly larvae (Amaurosoma).

There are over 500 species in the family. Many of these are associated with accumulations of decaying plant debris.

There are over 3000 species in family real flies (Muscidae). Their appearance is easy to imagine, remembering the well-known housefly.

Many species of real flies are synanthropic, that is, more or less closely related to humans. Some of them, for example housefly (Musca domestica, fig. 423), are no longer found in the wild, outside villages and cities. Manure, feces, various garbage - these are the garbage where the larvae of the housefly develop - a constant companion of human settlements. The reproduction rate of this species is striking. At one time, the female lays on average about 100-150 eggs, but with sufficient nutrition, egg-laying is repeated with an interval of 2-4 days, so that her total fertility is 600, and in countries with a hot climate, 2000 or more eggs. If the larvae, pupae, and the flies themselves did not die, then the offspring of only one female by the end of summer could exceed 5 trillion (5,000,000,000,000) specimens.

House fly larvae, like other higher flies, do not have a head. They liquefy food, releasing digestive juices on it - this method of digestion is called extraintestinal. As a result, the entire colony of fly larvae is floating in a liquefied semi-digested medium, which is constantly swallowed by them (Table 55). As a result, food is used with amazing savings. In one liter of horse or cow manure or in the same amount of kitchen waste, from 1000 to 1500 fly larvae can develop at the same time, and up to 4000 in pig manure.

House flies are dangerous spreading infections. Each of them, having been on feces and various kinds of waste, carries on the surface of its body about 6 million microorganisms and at least 25-28 million in the intestines. And I must say that pathogenic bacteria in the intestines of a fly are not digested and are completely viable excreted. The flies were found to contain typhoid and paratyphoid bacilli, dysentery bacillus, cholera vibrio, tuberculosis bacillus, anthrax spores, the causative agent of diphtheria, as well as worm eggs. Therefore, the fight against house flies is an important link in the general system of combating human diseases.

Along with the larvae of the housefly, many other species of this family develop in the manure and refuse. Larvae house flies (Muscina stabulans) also begin their lives as consumers of decaying plant substances, but then, having got stronger, begin to feed on the larvae of other Diptera, i.e., they become predators. Larvae are among the most active predators in manure. common cephalic (Hydrotaea dentipes), which kill housefly larvae, flies and other Diptera species.

Competition among the inhabitants of the dung is usually extremely fierce. Some species of flies have developed a special life rhythm that makes it possible to avoid large losses in this competition: they lay not eggs in the manure, but live larvae, often already quite large. So, the larvae of some species of the genus dazifora (Dasyphora) develop in the mother's body up to the third stage, that is, they get into the manure when they are almost adult.

It is often said that flies become angry by autumn and begin to bite. Such a popular omen arose because it was by the fall that flies-flies appear, in the first place autumn burner (Stomoxys calcitrans). This fly, equipped with a piercing proboscis, is a bloodsucker and is harmful as a mechanical carrier of anthrax, tularemia and other diseases.

Another blood-sucking fly has become notorious, carrying a special kind of trypanosomes - the causative agents of the "sleeping sickness" common in Africa. Trypanosomes themselves are constantly found in the blood of antelopes, which are not harmed. Fly tsetse (Glossina palpalis), having drunk the blood of such an antelope, often then bites a person, passing him trypanosomes. The disease manifests itself in deep exhaustion and usually ends in death.

Another species of the same genus, Glossina morsitans, spreads a similar disease, which, however, only affects animals. Interestingly, in these flies, the larva fully develops inside the swollen abdomen of the female, feeding on special secretions of the accessory glands. After leaving the mother's body, the larva immediately pupates in the soil.

Real flies that develop in living plant tissues are very serious pests. Plants infested with flies usually rot and die. Cabbage and other cruciferous plants are badly damaged by cabbage flies, the grayish color of which makes them very similar to the housefly. Their larvae sharpen holes in the roots of damaged plants, contributing to the spread of root rot. Especially dangerous spring cabbage fly (Chortophila brassicae), the first generation of which attacks seedlings, causing plant death.

Similar to cabbage, but lighter colored onion fly (Ch. Antiqua). The larvae of this pest eat the insides of the bulbs in the gardens. Beets are damaged by larvae beet fly (Regomyia hyosciami), which eat out vesicular cavities in the leaf parenchyma. In the stalks of cereals lives winter fly (Hylemyia coarctata). Its larvae cause damage similar to that of a Swede. Larvae spring fly (Phorbia genitalis), also inhabiting the stalks of wheat and barley, gnaw out spiral passages in them.

* (Sakharov's locust, described below, is sometimes isolated into an independent family Acridomyiidae or included in the Anthomyiidae family.)

Carrion flies (Calliphoridae) is a predominantly tropical family of about 900 species, some of which are common all the way to the northernmost regions. Like many tropical insects, they are bright green or blue with a metallic sheen (Table 60).

In tropical countries, closely related species also attack humans. Usually, the females of these species lay their eggs on the earthen floor in the hut where people live, and the larvae then actively penetrate the skin of humans and domestic animals.

During the First World War, an incident occurred that helped to discover a completely unexpected beneficial effect of the larvae of carrion flies settling in festering wounds. Two seriously wounded soldiers of the German army were picked up only seven days after the battle, and the wounds of each of them were infested with the larvae of carrion flies.

After the wounds were washed, they were in such good condition that this fact attracted the attention of surgeons, especially since usually such wounds ended in death.

Studying the action of fly larvae such as green carrion flies (Lucilia), blue carrion flies (Calliphora), and others showed that, feeding on the decomposing tissue of the wound, they not only remove these tissues and small fragments of bones, but also with their secretions prevent the growth of pathogenic bacteria. In addition, they release allantoin into the wound, a substance that promotes wound healing.

However, the use of flies from the natural environment does not always end successfully, since they can introduce tetanus sticks or gangrene bacilli into wounds. Therefore, for the clinical treatment of difficult-to-heal wounds, flies are bred in the laboratory and obtained completely sterile, that is, free from any pathogenic microbes, larvae.

Larger family gray meat flies (Sarcophagidae), numbering over 2000 species, is poorly represented in the tropics and flourishes in the more temperate zones of the northern hemisphere.

The body of these flies is most often painted in ash-gray tones with a black checkered pattern or rounded spots.

In the forest zone, larvae develop on carrion common meatfly (Sarcophaga carnaria). Adult flies, gray with black patterns, can be found on flowers, their sizes reach 20 mm, but there are also dwarfs only 6-8 mm.

In Southern Europe and Central Asia common volfart fly (Wohlfahrtia magnifica), which differs from other species in the presence of three rows dark spots on a gray abdomen. Females of this species, like most other species of the family, are viviparous. They forcefully throw larvae into ulcers and wounds, as well as into the eyes, ears and nostrils of various animals. The larvae feed on living tissues, causing severe torment, often ending in death. This species is especially harmful in pastoral areas.

There are many cases when the victim of the larvae of the wolfart fly was a person, in whom they usually caused prolonged suppuration (myiasis) on the head or penetrated into the nasal cavity. Laying passages in the tissues, the larvae not only give rise to painful sensations: the damaged areas swell and fester, the tissues partially die off, and bleeding begins from the nose. After removal of the larvae, all these phenomena disappear.

Family subcutaneous gadflies (Hypodermatidae), as its name suggests, includes species whose larvae develop in nodules under the skin of animals.

The adaptations of hypodermic gadflies are interesting to ensure that in strictly defined periods in nature, a high number of adults is created, which is important for the successful reproduction of species. Although the gadfly larvae fall out of the fistula into the soil at different times, the first pupae formed in spring develop more slowly compared to those that are formed somewhat later. Therefore, the vast majority of pupae finish development almost simultaneously, and within a few days a large number of adult flies emerge from them at once. Moreover, gadflies emerge from pupae at a strictly defined time of the day, in the temperate zone, usually from 7 o'clock. 30 min. up to 8 hours. 30 min. in the morning. All emerging individuals flock from large territories to the same, constant from year to year points, usually to the tops of some hills or mountains, to certain sections of roads, paths, etc. Males in these clusters are much more numerous than females. If the gadflies are scared away from these places, then after a while they return there again. On the basis of these observations, even proposals were made to combat adult gadflies precisely in places of their accumulation.

Females of hypodermic gadflies, laying eggs, behave very actively and for a long time in whole flocks chase animals that turn to panic flight. It is possible to milk cows during the flight of gadflies only when they stand in the water - gadflies do not attack them at this time. The amount of milk given in tired animals is halved, their fatness drops sharply. Reindeer husbandry suffers huge losses from hypodermic gadflies, since the value of skins perforated by larvae is greatly reduced.

Sometimes, though very rarely, a person is a victim of hypodermic gadflies. Usually these are people caring for pets. The migration of the larvae of subcutaneous gadflies in the human body often ends with their penetration into the head - after all, the larvae migrate, like in animals, upward. The most severe diseases are caused by the introduction of larvae into the eye. In this case, an operation is required to extract the larva, which leads to partial loss of vision.

Bovine gadfly (Hypoderma bovis) is distributed in Europe, North Africa and Asia. Females of this species lay eggs on the hairline of animals, mainly on the legs. Mainly cattle are affected. After 4-6 days, larvae emerge from the eggs and, having penetrated under the skin, begin complex migrations. First, they rise along the connective tissue layers to the esophagus and penetrate its walls, then descend into the chest and here they go to the place of their final development, which flows under the skin in the intercostal spaces, where nodules are formed.

An adult gadfly reaches a length of 14 mm, its body is covered with thick hairs. The hairs on the breast in the anterior half are yellowish-gray, in the posterior half, black; abdomen in the middle part with black hairs, its end is rufous, and the base is even lighter.

Reindeer are very heavily infected with northern hypoderm. On average, 200 gadfly larvae develop on one deer, and the maximum infection is calculated at 1000-1500 larvae.

Larvae of different species gastric gadflies (family Gastrophilidae) develop not only in the stomach, but also in other parts of the intestinal tract. At the same time, females lay eggs on the hair of the animal, but in strictly defined places - more often on the hairs of the lips, cheeks or intermaxillary space. In this case, the larvae emerging from the eggs independently reach the oral cavity and descend into the intestines. Some gastric gadflies lay eggs on the hairline of those parts of the animal's body that it scratches with its teeth. In this case, the larvae do not leave the shell of the egg, maintaining their viability for 90-250 days - a period of time sufficient for the animal to accidentally lick the eggs of gadflies during scratching, from which larvae immediately appear in the oral cavity. Further migration of larvae to the stomach or any other part of the intestine occurs quickly. Here, the larvae attach to the walls by mouth hooks, feed on secreted mucus and blood, and, when they reach maturity, are carried out along with the feces. They pupate in the soil.

Gadfly hook (Gastrophilus intestinalis) is one of the most numerous gastric gadflies. It is a large yellowish brown species, up to 15 mm, with spotted wings. The fly's chest is covered with protruding light yellow or brownish hairs; on the abdomen, the hairs are straw-yellow with some admixture of dark ones.

The female lays eggs on the hairs of the host's lips. There is evidence that the female is also able to stick eggs into the skin of the animal with a sharp attachment process. The larvae that emerged from the eggs develop in the oral cavity before the first molt, and then descend into the stomach. At the end of development, the larvae are carried into the rectum, where they reattach to the walls and live for a long time.

Interesting development cycle of representatives families nasopharyngeal gadflies (Oestridae). Females of all species of this group are viviparous, but by the time they emerge from pupae, the larvae in eggs do not have time to develop. Females spend almost three weeks in complete immobility, waiting for the moment when young larvae appear in their abdomen from eggs. After that, a period of active search for host animals begins. The female sprinkles several larvae each time directly into the nasal cavity of the animal, where they develop due to mucous and pathological blood secretions. Together with the larvae, the female sprinkles a certain amount of liquid. The larvae are very sensitive to drying out and, even before the evaporation of this liquid, they must get on the mucous membrane of the nasopharynx. Some animals, such as deer, inhale dust and fine sand during a gadfly attack, thereby drying out the nasal cavity and, to some extent, protecting themselves from the larvae.

In conditions temperate climate Young gadfly larvae overwinter, and their development ends in spring and summer. Adult larvae emerge through the host's nostrils.

There are known cases of attacks by nasopharyngeal gadflies on humans. In this case, the females usually spray the larvae into the eye. The larvae quickly spread and scratch the mucous membrane of the eye with their hooks, causing its inflammation (conjunctivitis).

Great harm to livestock brings kruchak, or sheep gadfly (Oestrus ovis), which develops in the nasal cavity, frontal sinuses and cavities at the base of the horns of sheep. The female of this species lives up to 25 days, and the first 12-20 days are necessary for the final formation of the larvae. Then the female vigorously searches for the host and quickly attaches the offspring, since even a slight delay in laying the larvae leads to the fact that the larvae creep in the body of the female and cause her death. In total, the female can lay up to 500 eggs.

The losses caused by the kruchak are very great. With the development of more than 50 larvae in the nasal cavity and frontal sinuses in sheep, a "false twirl" is observed - a disease in which the sheep circle in one direction and die after a few days. When the larvae enter the respiratory tract, death occurs from pneumonia.

The harm from gadflies is extremely great. Huge funds are spent annually on the fight against these Diptera, however, the fight against gadflies is effective only when it is carried out on a planned basis and large areas... In the USSR in the last decade, as a result of the use of a complex of chemical and preventive measures struggle made significant progress in the extermination of gadflies.

The body of adult flies, especially the abdomen, is usually covered with strong bristles; the last segment of the antennae is laterally compressed. Tahinas are sun-loving insects, in summer they can most often be found on flowers, where flies feed on nectar or honeydew. However, they avoid high temperatures and hide in shelters during the hot hours of the day. Only a few species of tahin are characterized by a twilight period of activity.

Although fertilization occurs in the first hours after the appearance of females from the puparia, eggs are not laid immediately. For different types of tahinas, it takes 8 to 25 days for the eggs to mature in the ovaries. After that, the entire behavior of females changes dramatically, since the period of feeding on plants is replaced by a period of intensive search for a host.

Among the representatives of the family, there are relatively few species of monophages that develop exclusively at the expense of any one species of animals. Most tahinas successfully attach their offspring to a large number of different hosts, which, however, belong to one family or order, that is, more or less related. The larvae that emerged from the eggs swallowed with food pierce the intestinal wall and, with the flow of hemolymph, reach certain organs, where they develop. In some species, the larvae are placed in the supraopharyngeal ganglion, in others, they penetrate the salivary glands or linger in muscle tissue.

Growing up, the larvae begin to have difficulty breathing and are usually attached by the posterior end of the body to one of the tracheal trunks of the host so that the spiracles of the larva emerge into the lumen of the trachea.

The larvae that have successfully penetrated the host's body begin to feed on its tissues, but in the first period they spare the vital organs. Only at the final stage of development, the larva secretes a large amount of digestive juices in the host tissue, causing their complete digestion. Having finished feeding, adult larvae most often leave through the integument of the body and pupate in the soil.

The eggs of the bloodsucker mature in the body of the female, and the larvae hatch from them. The food for the larvae is the secretion of special accessory glands. Eggs in the ovaries are formed alternately, and therefore the female feeds in each subsequent period of time, one larva. The larva on nutritious food grows quickly and leaves the mother's body only so that, having climbed into the soil, it immediately pupates. Therefore, the bloodsucker and some other Diptera that give birth to larvae ready to pupate are often combined into the "puppeteer" group.

Avian bloodsuckers, as a rule, can successfully live on many species of birds. When birds come into contact with each other, flies often change owners. The species composition of bloodsuckers is especially diverse on birds of prey that hunt other birds: while the predator eats its prey, all the bloodsuckers living on it move to a new host.

In bloodsuckers of bats, two methods of attachment of nascent larvae have been noted. During this period, the females of most species leave the host and attach the larvae to some kind of substrate - on the stone walls of caves, on the bark of trees, on the walls of attics, where mice hide during the day, etc. The bloodsucker that emerged from the puparium independently searches for the owner. Only a few species attach nascent larvae to the hair of bats.

There are about 150 species in the family. They are all relatively small - length common bat bloodsucker (Nycteribia pedicularia) only 2-3 mm... Despite some external similarity, the bloodsuckers of bats are not considered closely related to the family Hippoboscidae discussed above. It is believed that they arose independently of dipterans, which initially developed on garbage in bats' shelters, and then adapted to feeding on their blood.

Superclass: Insecta \u003d Linnaeus Insects, 1758 \u003d Insects

Order: Diptera \u003d Diptera (mosquitoes and flies);

Family: Diopsidae \u003d Diopsida (Stem-eyed)

Family: Culicidae \u003d Blood-sucking mosquitoes [real]

Family: Mycetophilidae Winnertz, 1863 \u003d Mushroom mosquitoes

Family: Ceratopogonidae \u003d Bites (lecture)

Family: Simuliidae \u003d Midges (lecture)

Family: Muscidae \u003d Real flies

Family: Hippoboscidae \u003d Bloodsuckers

Family: Asilidae \u003d Ktyri

Family: Hippoboscidae \u003d Bloodsuckers

Family: Gasterophilidae \u003d Gadfly

Family: Hypodermatidae \u003d Subcutaneous gadflies

Family: Glossidae \u003d Tsetse flies

Family: Phoridae \u003d Humpbacks

Order: Diptera (Mosquitoes and flies)

The order Diptera (including mosquitoes and flies) is relatively young among insects. The earliest finds of fossil flies date back to the Jurassic period, about 150 million years ago. Their heyday began with the expansion of flowering plants and mammals across the planet. The mouth of dipterans is designed so that they can feed only on liquid food: the nectar of flowers and the blood of animals.

About 85-100 thousand species of Diptera are known. They are so named because only the first pair of wings is developed and used in flight.

The malaria mosquito, when it sits on something, raises its abdomen, the usual squeaky mosquito keeps it parallel to the surface or even lowers it a little. The larvae of the squeaky mosquito hang vertically at the surface of the water, head down, and the larvae of the malaria - horizontally.

Both insects are from the family of real mosquitoes, in which one and a half to two thousand species. From the tundra to the tropics, you can find representatives of this family, and everywhere they are the most obnoxious of bloodsuckers. However, not all real mosquitoes suck the blood of animals; many species are content with nectar and plant sap. And even among bloodsuckers, only females feed on blood, males - only on plant sap.

By autumn, all males of an ordinary mosquito die, only females overwinter in different cracks. In the spring they wake up and hurry to the water. Eggs are laid on its surface, which float in small piles with a diameter of about 7 millimeters, and in each pile there are several hundred eggs. If for some reason a mosquito female could not drink blood before oviposition, then she lays eggs less - 40-80.

The larvae hatch soon. They are heavier than water, and in order to stay near the surface, they have to make considerable efforts: twitching and wriggling, they float up and hang down with their heads at the surface film of water. But there is a little danger, they immediately descend. Then they surface again. They feed on microscopic algae, the remains of dead animals and plants, filtering each liter of water a day.

After about three weeks, mosquito larvae pupate. Pupae are lighter than water and float to the surface by themselves. They already have eyes, though still hidden under the covers of the pupa. But these covers are transparent, and the sudden illumination frightens the mosquito pupae - they all immediately sink into the depths. But soon they surface again. Pupae do not eat anything: their mouth organs from filtering ones turn into piercing-sucking ones. Other transformations are quickly accomplished, and after a few days a long-legged winged mosquito emerges from its burst covers.

On quiet, windless evenings, male mosquitoes gather in flocks: they usually hover over some tree, bush, bell tower, even over a person walking along the road. Turning their heads against the wind, rhythmically taking off and falling, the mosquitoes seem to dance in place. The smell that the special glands of the mosquito emit in flight is amplified thousands of times when they gather in a flock. While dancing, mosquitoes scatter it in all directions, and, attracted by this smell, females rush to dance from all directions. Sometimes they also gather in a flock, which winds just below the dancing males. Suddenly one or the other female breaks out of the flock and soars up, in the company of males. A moment, and the united couple falls to the ground.

How does a male find a female so quickly among thousands of mosquitoes scurrying up and down in disorder? He hears her! Hears the beating of her wings. They vibrate five hundred times a second, and the antennae of the male begin to vibrate in unison with their vibration. A special organ located in the second segment of the antennae perceives only the beating of the wings of a sexually mature female. It is a sexually mature, immature one that flaps its wings in a different rhythm, just like the male mosquitoes. Therefore, the antennae of a mosquito, tuned to a certain vibration frequency, do not respond to the flapping of the wings of other males in the flock.

The old question: in order to lay mature eggs, whether the females of all mosquitoes must first drink blood, has not been finally resolved. Apparently, for some subspecies of ordinary squeaky mosquitoes, this condition is not necessary. And hungry females develop eggs, only fertility is much less than that of those who have sucked blood.

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