Science and technology

Sexual dimorphism. One of the amazing phenomena that is often found in Diptera is sexual dimorphism, i.e. significant differences in appearance between males and females of the same species. For example, as noted above, males of many species have compound eyes that are holoptic; are in contact with each other, while in females they are separated by a frontal stripe (dichoptic). In female mosquitoes, the antennae are slightly 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, wings are absent or greatly reduced, while in males they are normally developed. In one of the families of Diptera, in females, two veins of the wing merge at its edge, and in rare males, they are separated throughout. In another group, the legs, antennae, or other body parts of males often bear tufts of hairs with a metallic sheen, 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 the sexes in coloration are common, but usually not conspicuous. However, sometimes this difference is quite significant; for example, males of one American weevils are pale rufous, while females are nearly black.

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

Some Diptera avoid predators with the help of patronizing, i.e. camouflage, coloring. The dark color of mushroom gnats makes them invisible when they sit motionless in crevices under fallen trees. Other Diptera have a "dismembering" coloration. For example, in liriopids, 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 add up to a single whole.

LIFE CYCLE Like other higher insects, the Diptera life cycle is complex and includes complete metamorphosis. The eggs of most species are oblong and light. They hatch into larvae, usually elongated, roughly 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 varies, but usually there are two or three. Then comes the pupal stage. In some Diptera, it is formed inside the larval skin, which turns into the so-called. "puparia". In the end, the pupal shell is torn, and an adult insect (imago) is born.

Life cycle of a house fly. On the example of a house fly, one can trace the course of development of Diptera. To lay eggs, the female seeks out accumulations of decaying organic matter, such as dung or garbage heaps. Thus, the fly instinctively leaves the clutch where the inactive larva will be provided with a sufficient amount of food. At one 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, the development of eggs 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 after 24–36 hours, and the second one about a day later. The larva in the third stage feeds for another 72–96 hours and grows to a length of approx. 12 mm, and then pupates.

An oblong pupa is formed inside the last larval skin, which becomes the pupal sheath (puparium). This shell changes its off-white color to brown and hardens. Within 4–5 days, inside the 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) injected into it, protrudes into the frontal part of the head. Under its pressure, the “lid” of the puparia opens, releasing an adult insect. It crawls out of the decaying debris or soil in which pupation has occurred, spreads its initially crumpled wings and flies away to feed and mate, starting a new life cycle.

Another curious form of reproduction found in some Diptera is pedogenesis, i.e. the appearance of offspring in outwardly immature individuals. So, in gall midges, an adult female lays only 4 or 5 eggs, from which large larvae are formed. Within each of them, from 5 to 30 (depending on the species and 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 a 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 has been found in other Diptera, for example, in some midges. Females lay unfertilized eggs, from which only females emerge. Parthenogenesis can be cyclic, continuous or sporadic. See BREEDING;

GEOGRAPHICAL DISTRIBUTION On land, there is, perhaps, no such corner where Diptera would 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 large zoographic regions is characterized by its own set of taxa, but 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. Approximately half of them were unwittingly settled all over the planet by man. These species include the ubiquitous housefly, the peeper mosquito ( Culex pipiens), gastric horse gadfly and autumn zhigalka. Among the approximately 130 Diptera families, less than 20 are truly cosmopolitan, although the ranges of many others are not much narrower; they are distributed subcosmopolitan.

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

Diptera of mainland islands are usually close to those living on the nearest continents, but on more isolated oceanic islands, even though they belong to widespread groups, they are often very peculiar. Apparently, a single, accidental hit 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 can explain, for example, the fact that almost a third of the 246 Hawaiian Diptera species belong to just one family.

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

Larvae. The habitats of Diptera larvae are much more diverse than those of adults and include almost all types of ecological niches. Some attack aphids or gnaw on 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 burrow through decaying wood, fungi, or soil, feeding on organic debris or microscopic invertebrates.

Often they live in stagnant and flowing bodies of water of any size, where they feed on vegetation, microorganisms, or insects of other species. Most of these aquatic larvae prefer shallow places, but in some bell mosquitoes they dive to depths of more than 300 m. If their development requires a good supply of oxygen, they attach themselves to the stones of river rapids or mountain streams. The larvae and pupae of some Diptera prefer waters with a high content of alkalis or salts, and in one Californian species they live in oil pools. 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 filling the pitcher leaves of insectivorous plants, where other insects drown and digest.

EVOLUTIONARY HISTORY Judging by the fossil finds, insects already existed in the Devonian period, i.e. OK. 300 million years ago. However, until the Upper Triassic (about 160 million years ago), the remains of Diptera were not found among them. The most primitive representatives of this order are similar to long-legged and united in the extinct family Architipulidae. Many different Diptera, 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 shales from Florissant, Colorado, many fossil centipedes, mushroom mosquitoes, and other Diptera, characteristic of swampy habitats, have been found. Among them, even the tsetse fly is noted, although at present this genus is found only in Africa. The study of Baltic amber and fossils of Florissant showed that by the middle of the Cenozoic era Diptera had passed most of their evolutionary development.

SIGNIFICANCE IN HUMAN LIFE Many species of Diptera are best known as disease vectors, annoying bloodsuckers, and crop pests. Most effective chemical methods to combat 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 some of the medically important Diptera.

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

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

cereal flies from the genus hippelates, feeding near the eyes, they easily introduce a bacterium into them that causes acute epidemic conjunctivitis.

Bloodsucking. Blood-sucking dipterans, even if they are not carriers of diseases, such as biting midges, autumn zhigalka, many mosquitoes and midges, during a mass attack worsen the state of human health, causing itching and allergic reactions, sharply reducing efficiency. In addition, all of these species remain potential carriers of pathogens.

Pests of agricultural plants. Compared with beetles, butterflies, herbivorous bugs and representatives of some other orders of insects, dipterans do relatively little harm to agricultural plants. Representatives of only 5-6 families have a certain significance in this sense. Serious pests of cereals include the Hessian fly from the family of gall midges. This species damages mainly wheat, but is also dangerous for barley and rye. Hessian fly larvae feed on plant sap at the base of the stems, causing them to stun 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. Thus, the larvae of the apple moth spoil apples, damage the fruits of citrus and other fruit trees, significantly reducing the yield. Larvae of other Diptera gnaw out passages in various plants. As an example, three species from the family of flower girls can be cited: sprout, cabbage spring and onion flies. Representatives of the family of cereal flies, living in many parts of the world, harm cereal crops.

CLASSIFICATION The Diptera order is divided, according to different systems, into 121–138 families, which are grouped into two or three suborders. When classifying, the most commonly used features are venation of the wings, the length of the antennae and the number of segments in them, the number and arrangement of setae and spines on the body and legs, the configuration of the external genital appendages, the presence or absence of simple ocelli, and the shape of the opening through which the imago leaves the pupal skin or puparia. The color, size and shape of the body do not always make it possible to judge the degree of kinship, because natural selection often leads to an outward resemblance of representatives of very distant groups. The scheme proposed below, which includes only the most important families, is only one of the possible ways of classifying the approximately 100,000 species of Diptera; the number of species in families is approximate.

Suborder Nematocera(long-haired). These insects are characterized by long antennae with more than three segments. The group includes 36 families. The 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; puparia is not formed.

Tipulidae (long-legged): 10,000 species, cosmopolitan.

Psychodidae (butterflies): 400 species, sub-cosmopolitans.

Chironomidae (bells, or jerks): 2000 species, cosmopolitans.

Ceratopogonidae (midges): 1500 species, subcosmopolitans.

Culicidae (true mosquitoes): 1600 species, cosmopolitan.

Mycetophilidae (fungi gnats): 2400 species, cosmopolitans.

Cecidomyiidae (gall midges): 4500 species, subcosmopolitans.

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

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

Blepharoceridae (Reticulata): 75 species, found in the highlands.

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

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

Stratiomyiidae (lionfish): 1500 species, subcosmopolitan.

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

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

Bombyliidae (Buzzers): 2000 species, sub-cosmopolitan, but mainly in North America and the Mediterranean.

Asilidae (Ktyrs): 5000 species, sub-cosmopolitan, but most diverse in the tropics.

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

Dolichopodidae (greenfinches): 2000 species, cosmopolitans.

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

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

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

Pipunculidae: 400 species, mostly on the northern continents.

Syrphidae (Hoverflies): 4000 species, sub-cosmopolitans.

Conopidae (bigheads): 500 species, subcosmopolitans.

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

AVERAGE LENGTH OF DIPTERS, MM
buzzed
Bolshegolovka
Midge
Goldeneye
hessian fly
Gadfly gastric
Horsefly bull
Runet sheep
Mosquito
spotfly
Ktyr
Gadfly subcutaneous
hoverfly
hedgehog
American meromiza

Trypetidae (stripedflies): 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 (shorebirds): 800 species, mainly in Eurasia and North America.

Chloropidae (grass flies): 1200 species, cosmopolitan.

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

Anthomyiidae (flower girls): 3000 species, cosmopolitans.

Calliphoridae (carrion flies): 500 species, sub-cosmopolitan, but mostly in the Northern Hemisphere.

Sarcophagidae (grey blowflies): 1000 species, sub-cosmopolitan, but mostly in the tropics.

Muscidae (true flies): 150 species, cosmopolitan.

Tachinidae (Hedgehogs): 5,000 species, cosmopolitan but most diverse in the tropics.

Oestridae (nasopharyngeal gadflies): 150 species, sub-cosmopolitan, but mostly 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 in almost every corner of the planet Earth. They look very different - for example, blue flies, weevils, houseflies, midges and mosquitoes look very little alike.
The fly is one of the most common and annoying insects on Earth. Her flight both delights us with its accuracy 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 phylum Arthropoda, class insects, order flies and mosquitoes, family flies. The body length of a fly ranges from a few millimeters (drosophila) to 1.5 cm (housefly) and even up to 2 cm. The body length of a representative of the largest fly species is about 7.5 cm. The fly lives from 1 to 2.5 months.

Order Diptera or Flies and mosquitoes (Diptera)

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

General characteristics of the Diptera detachment

In the vast order of Diptera, there is a huge variety in size, shape and color of the body. The length of some gall midges is only 0.4 mm with a wingspan of just over 1 mm. Some ktyrs reach a length of 50 mm, and the wingspan of individual weevils exceeds 100 mm.

Rice. one . General form Diptera

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

Although large swarms of Diptera are often seen, 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 swarm, attracted by the smell of food, convenient place for rest or mating.

Diptera can flock to the light along with insects of other species. Mosquitoes, bellworms and weevils 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 noise of their wings with its characteristic tone attracts females. In experiments, by reproducing sounds similar to the squeak of female mosquitoes of certain species, it was possible to cause swarming of the corresponding males. Accumulations are especially characteristic of blood-sucking dipterans (midges). If the species is active mainly in the dark time of the day, it is called nocturnal, if it is daylight, it is called daytime; an intermediate twilight group is also distinguished.

Hanging flight is observed in various species of Diptera, but is especially developed in hoverflies and hummingbirds. Representatives of these families fly fast and perfectly maneuver in the air. It is not uncommon to observe how they hover motionless in place, intensively working their wings, only to suddenly disappear from view.

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

Among the 33 modern orders of insects, the Diptera order occupies one of the first places in terms of abundance and diversity of representatives, yielding in this respect only to beetles, butterflies and hymenoptera. 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 being completed.

The main features that separated Diptera 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 higher Diptera also in the reduction of the head capsule and, ultimately, in the development of extraintestinal digestion.

The body shape of adult dipterans 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 compound eyes - in Diptera often occupy most of the surface of their rounded head. Additionally, on the crown there are, although not all, 2-3 dotted eyes.

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 distinct characters that distinguish the suborder of long-whiskered Diptera (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 pinnate bristle. Antennae are mainly organs of perception of smells. On the surface of each of the segments there are olfactory tubercles specially adapted for this purpose. Often, the antennae of male Diptera are much more complex than those of females. These secondary sex differences are usually seen in mosquitoes; in flies, they appear more often in the size of the eyes.

The mouthparts of Diptera (Fig. 407) are strongly modified and are suitable for taking mainly liquid food. The most perfect adaptation for this is the proboscis of higher flies, formed by the lower lip and ending in sucking lobes.

In blood-sucking mosquitoes, the mouth parts are strongly elongated, the lower lip forms a groove in which piercing stylets are located: needle-shaped upper jaws (mandibles) and lower jaws (maxillas). Between them is the subglottis, through which the duct of the salivary glands 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-like solid groove, the opening of which is covered by an upper lip of the same shape, linked to the lower one by special outgrowths. The teeth, which in the proboscis of higher flies are located on the sucking lobes and serve most species for scraping off solid food particles, are greatly enlarged in bloodsuckers and are used to open the integument of animals. In this case, the fly puts its proboscis vertically against the skin of the animal and sets in motion the rollers on which the pre-oral teeth are located. Notching the top protective layer skin, these teeth rather quickly drill out the wound. Stingers, the tse-tse fly, and other closely related species of Diptera have such proboscises. When piercing the covers of insects predatory flies- ktyryami and greenfinches - the main role is played by the lower lip together with the subglottis. In such bloodsuckers as horseflies, the wound is applied mainly by mandibles.

Three thoracic segments of Diptera are tightly soldered together, forming a strong thoracic region - a receptacle for powerful muscles. He serves reliable support for wings during fast flight. Halteres are also located here - short club-shaped appendages, which are a modified second pair of wings. They are considered organs of balance. The mesothorax - the most powerful thoracic segment - is equipped with a semicircular outgrowth - a shield on the posterior edge.

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

The structure of the legs of Diptera is closely related to their way of life. Movable, fast-running flies have short strong legs. Mosquitoes, on the other hand, usually hiding among the vegetation during the day, have long limbs adapted for climbing among the interweaving of grass stalks or in the foliage of trees and shrubs. The paws of the legs 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.

Ingenious experiments have shown 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 settled. If a hungry fly is brought to a sugar solution so that it touches it with its paws, then the fly puts forward its proboscis for sucking. When the sugar solution is replaced with water, the fly does not react at all.

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 setae. The location of these setae is often used as a feature for distinguishing individual families, genera, and species of the order.

The idea of ​​Diptera larvae as whitish, legless, and headless "worms" swarming in manure and rubbish heaps does not at all reflect the true diversity of their forms and is based on the most superficial acquaintance with the order.

First of all, it should be emphasized that in the larvae of all long-horned Diptera, the head is well developed and often equipped with strong jaws, with the help of which the larvae feed on plant roots or decaying organic matter. The only exception is a rare family of long-whiskered dipterans - hyperoscelididae (Hyperoscelididae). Hyperoscelidid larvae completely lack a head capsule, their head segment bears only a pair of antennae and a mouth 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 oral 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 method of digestion, which is called extraintestinal. In this type of digestion, food is pre-digested outside the body of the larva under the influence of the digestive juices secreted by it, and only then is it swallowed and absorbed.

The body shape of the larvae is varied. Usually it is worm-like, but sometimes it is so unusual that it can baffle an inexperienced taxonomist. Very bizarre, for example, flat larvae living in fast mountain streams deuterophlebiid(Deuterophlebiidae) - a small family distributed in the mountains of Altai, Tien Shan, the Himalayas and the Rocky Mountains of North America. Each segment of the larvae bears from the sides along a long outgrowth with a sucker at the end. Alternately moving these outgrowths, the larvae are able to move slowly 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.

Very remarkable larvae ptychopterid(family Ptychopteridae), developing in fresh water. They have a well-developed head, dense integument with dense rows of spines, and a long windpipe 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 significance of the tube in the life of the larvae is clear: with its help, the larva can, without losing contact with the atmospheric air, search the bottom of shallow water or the underwater parts of plants in search of food.

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

Perhaps the only constant feature of Diptera larvae is the absence of pectoral (true) legs. The absence of legs in fly larvae is in some cases compensated by the development of various outgrowths of the body, resembling 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 bekasnits(Leptidae), numbering more than 400 species. In most of them, the larvae are worm-like and outwardly do not differ from the larvae of a house fly. But in the larvae of the ibis fly (Atherix ibis), which live among the stones at the bottom of fast-flowing rivers, each trunk segment has a pair of hooked "false legs" that serve as perfect organs of movement.

Diptera larvae are found in large aggregations in an abundant food substrate. The usual places of mass development of larvae of higher flies are decomposing animal corpses, garbage dumps, latrines, etc.

Mushroom mosquito larvae (Mycetophilidae) bring a lot of frustration to mushroom pickers. In most cases, it is their long white larvae with a black head that teem on the breaks of "wormy" mushrooms, making them completely unusable. True, fungal mosquitoes cannot be considered exclusively inhabitants of fungi, some of their groups are associated with decaying wood, plant debris, etc., where they also form large colonies.

Also, larvae of leaf mosquitoes are found in large clusters ( family Sciaridae). In some cases, when food is scarce, these masses of larvae may undertake massive migrations. Larvae military mosquito(Sciara militaris) are grouped into a long ribbon up to 10 wide cm, which, slowly wriggling, 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 metamorphosis, after a pupa has formed under the covers of the larval skin, these covers are shed and the pupa is completely released.

Long-whiskered 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 the adult larva not only does not shed 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 the adult fly, in order to be free, breaks out a round exit hole in it (Table 55).

This biological feature is the basis for the isolation of Diptera in the order, except for suborderlong-whiskered, or mosquitoes(Nematocera), two more suborders: short-horned diptera(Brachycera-Orthorrhapha) without puparia, and short-whiskered diptera(Brachycera-Cyclorrhapha), developing with a puparium. It is interesting that the larvae of some groups of Diptera, although they do not form a typical puparia, still pupate inside the larval skin. Among the long-whiskered Diptera, this method of pupation is characteristic of a small family scattopsid(Scatopsidae), numbering about 130 species, and for a few species of the family gall midges(Cecidomyiidae), such as the Hessian fly and some others. Lion larvae pupate inside the slightly altered larval skin from the short-horned straight-sutured Diptera.

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 water bodies, including seas with salt water, and fetid sewers, the thickness of the soil, various rotting plant substances that enter 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. To attach their offspring to suitable conditions is the task of adult flies, which are therefore good flyers. Many of them have interesting adaptations that increase the survival of larvae. It suffices to recall the birth of live larvae, which is common among higher Diptera, and in some cases the feeding of larvae with the secretions of special glands, when the larva leaves the mother's body, being already quite an adult.

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

It is not uncommon for adult Diptera to live solely on the nutrients that the larva has accumulated and do not feed at all. For other species it is enough to drink water, flower nectar or sweet juice flowing from injured trees. But not all adult Diptera are so harmless. Mosquitoes, horseflies, midges, midges, mosquitoes are annoying bloodsuckers. However, only females suck blood from them, while males are completely harmless. If the females of these Diptera do not drink blood, they will remain barren. Their bloodthirstiness 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, since 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 it is possible to evaluate the results of the experiment. When adult flies or their larvae are exposed to X-ray or radioactive radiation, numerous changes occur in their offspring - pigmentation of the eyes 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 signs of a male, and the other female or many signs of an individual were of an intermediate nature. The results of all these experiments formed the basis of many important scientific conclusions about the laws of heredity, which are studied by genetics.

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

In nature, there are numerous foci of various diseases that wild animals suffer from. 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 transmitted from person to person, but are nonetheless very widespread. Blood-sucking Diptera, attacking animals and humans, along with other blood-sucking arthropods, widely spread these diseases, transmitting the pathogen during blood sucking.

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

Equally dangerous carriers of infections are synanthropic Diptera, i.e., species that live in human dwellings. Visiting garbage and feces, they carry pathogenic microorganisms and helminth eggs on their bodies and in their intestines, leaving them on dishes, food, furniture, etc. It is not without reason that many teams of scientists are working to study the biology of one of these insects - the housefly - with the aim of her extermination.

Diptera larvae can also be serious pests of food stocks. Great harm, for example, brings nondescript cheese fly(Piophila casei), belonging to the family pyophilide(Piophilidae). Its white, shiny larvae develop in old cheese, ham, lard, salted fish, destroying these products. Adult larvae emerge from the 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 into a ring and straighten up sharply to make jumps.

For human health, cheese fly larvae pose a danger when foods contaminated with them are eaten. In the human intestine, the larvae are able to remain viable for a long time, causing ulceration of the intestinal wall, with symptoms reminiscent of typhoid fever.

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

The positive role of Diptera in nature and in the human economy is small in comparison with the harm they bring. They are tireless orderlies, cleaning the surface of the land from the waste accumulating here. Some groups of Diptera are known as soil formers and as enemies of harmful insects, which inhibit their reproduction.

Diptera are very widely distributed: from the tropics to the ice borders in the north and in the mountains. But even among the tropical representatives of the order, there are almost no particularly large and brightly colored species. Insect lovers pay little attention to them, preferring beetles and butterflies, although biologically Diptera are no less interesting and peculiar.

Suborder Long-whiskered Diptera (Nematocera)

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

Long-legged (family Tipulidae) are those large mosquitoes that fly out from under the 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 the vegetation, but also are a kind of protection from enemies. When the mosquito sits, its legs are widely spaced, and the approaching predator grabs the weevil 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 trembling 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, which leave only the end of their tail in the teeth of the pursuer, octopuses, sacrificing their tentacles, etc.

Long-legged larvae are inhabitants of a humid environment: soil, bedding, rotting 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 on living plant roots.

The process of digestion of these larvae is interesting. Plant foods, which consist mainly of very persistent substances - fiber and lignin, are difficult to digest. Single-celled animals come to the aid of the centipedes. They multiply en masse in the intestines of the larvae, releasing enzymes that promote the digestion of fiber. As a result, the food is enriched with substances that are absorbed by the larvae of the weevils. 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 foods are digested in the intestines 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 very complicated.

Among the few harmful species of weevils, it is worth mentioning garden weevil(Tipula paludosa) is an extremely widespread species, the larvae of which gnaw the roots of plants, including cultivated ones. In total, there are more than 2500 species in the family.

Family retina(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 terminal segments of the abdomen. On the middle abdominal segments there are six powerful suckers of a complex structure, the soles of which are covered with strong setae. With the help of suction cups, the larvae slowly move along the stones in jets of a fast stream, scraping off various growths from them.

Before pupation, the adult larva firmly attaches itself to the stone, the skin on its dorsal side bursts and its fragments are quickly carried away by stream jets, exposing the tender pupa. The integument of the pupa soon hardens, it darkens and becomes inconspicuous.

Mosquitoes emerging from pupae emerge from the bottom of the stream and fly to damp, shaded places, usually to rock crevices, where for the most part they hang quietly, clinging to ledges with long and thin legs.

In all zones of the globe, from the tundra to the tropics, with the exception of only hot deserts, one of the most annoying insects in the warm season are real mosquitoes (family Culicidae). In swampy areas, these insects pursue animals and humans in clouds, inflicting painful injections with a 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 bloodsucking tool as this stylet, which essentially consists of several stylets: two needle-shaped mandibles and two maxillae, an upper lip and a subglottis enclosed in a case - the lower lip. By the presence of a proboscis, it is easy to distinguish true mosquitoes from twitching mosquitoes, in which the mouth organs are not developed.

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

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

common eggs malarial mosquito(Anopheles maculipennis) swim alone on the surface of the water. After 2-3 days, larvae appear from the eggs, all further development which passes near the surface of the reservoir. Most of the time, the larvae spend in a horizontal position, attached to the surface film with non-wetting humeral 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 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. Its 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 caught by a filter of 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 submerged in water.

The disturbed larvae quickly dive, 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. Adult larvae transform into characteristic humpbacked pupae, which also stay near 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, the pupae quickly dive, waving the end of the abdomen several times, and then passively rise again to the surface.

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

In the evening, mosquito swarming can be observed: many dozens of males jostle in the air, forming a kind of "singing" cloud, while females fly into the swarm one after another and immediately leave it, dragging one of the males.

In fertilized females, the instinct of bloodsucking awakens. A hungry female is capable at a distance of up to 3 km determine the location of 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 in excess of 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 lays these eggs in the nearest body of water. Since that time, if the first time a female has drunk the blood of a person with malaria, she becomes dangerous, since her saliva is now teeming with sporozoites - the initial stage of development of malarial plasmodium.

Having re-sucked blood, the female again loses interest in food until maturation and laying the next batch of eggs. The female lives in the summer for about 2 months. By autumn, 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, cellars, where they hibernate. The development cycle of other types of blood-sucking mosquitoes is very similar.

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

Mosquitoes are of great importance as carriers 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 made it possible to sharply reduce the incidence of people. To combat mosquitoes, not only chemical, but also biological control measures have been successfully applied. A small viviparous gambusia fish imported from America acclimatized in Central Asia, where it became one of the main enemies of mosquito larvae. Interestingly, the larvae of some harmless species of mosquitoes are predatory, destroying the larvae of bloodsucking mosquitoes. One larva toxorhynchus mosquito(Toxorhynchites splendens), common in the tropics, destroys up to 150 larvae of other mosquitoes. This species has been successfully introduced to some Pacific islands to control harmful mosquitoes. In total, 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 has been aptly named "gnus". Together with horseflies, biting midges, midges, and in the south also mosquitoes, mosquitoes form hordes of Diptera, 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, myriads of mosquitoes and especially midges besiege humans and animals. eyes are covered with tears. Calves and foals sometimes die, bitten by midges. Large wild animals, for example, deer, make long migrations in the summer to the mountains and to the sea, where they escape from midges thanks to the wind. In coastal villages, field work is often stopped during the day due to midges , which are transferred to the night.Pets stop eating and gather under a canopy, where smokers are bred to drive away midges.

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

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

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

Extensive, numbering over 3000 species family twitching mosquitoes, or bells(Chironomidae), closely associated with large and small water bodies. On quiet warm evenings, over the banks of ponds and small rivers overgrown with reeds, you can hear a thin melodic ringing. This ringing is emitted by swarming mosquitoes, which then sharply 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 males are densely pinnate.

After washing a portion of silt from the bottom of the pond on a sieve, it is almost always possible to detect larvae of ringing mosquitoes. These larvae do not need atmospheric air: they absorb oxygen dissolved in water and release carbon dioxide through the tracheal gills and partly through the integument of the body. Red larvae live in the silt of various water bodies, including heavily polluted ones with a low oxygen content in the water. bloodworm(Chironomus plumosus) and a number of related species. These larvae intensively feed on microorganisms that colonize the silt, hiding in spider webs 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. The respiratory pigment hemoglobin is dissolved in their hemolymph - a useful adaptation to life in conditions of lack of oxygen.

In some lakes, bell larvae descend to a depth of more than 300 m, at such a 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, i.e., under conditions that would be fatal for many other insects.

Larvae have adapted to living in sea water pontomies(Pontomyia natans). The 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, look for females by running along the surface of the water.

biting midges (family Ceratopogonidae) - small mosquitoes, their body length rarely exceeds 3-4 mm. They are close to ringing 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. There are more than 1000 representatives in the family of biting midges, but only a few hundred species of bloodsuckers are well studied. Most of these species have variegated wings and, on this basis, are well distinguished from such blood-sucking Diptera as mosquitoes and midges.

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

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

Hatching biting midges usually stay near the breeding grounds among grass, shrubs and in the crowns of trees. Many species swarm in the evenings or early in the morning in calm weather, and the swarm consists mainly of males. Blood-sucking biting midges often enter livestock buildings en masse.

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

Biting mid-latitudes appear in May - June and, developing in several generations, reach the highest number 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 saturation with blood is sufficient for the full development of eggs in the ovaries of the female. After laying the first batch of eggs, the females attack the animals again and, if bloodsucking is successful, lay eggs again.

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

The most common and massive of the blood-sucking midges, not found only in the tundra, is burning midge(Culicoides pulicaris), which gives several generations over the summer. Its larvae are found in polluted fresh water bodies.

TO family midges(Simuliidae) include small humpback mosquitoes, whose body length does not exceed 6 mm. They are easily distinguished from real mosquitoes by 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 midges, they make up hordes of midges and equally willingly 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.

The female midges are experienced divers. To lay eggs, they descend under water, clinging to stones and plant stems. Some species of midges, however, prefer to lay their eggs on a calmer coastal strip or drop their eggs into the water while flying over a stream.

The larvae emerging 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 place. Therefore, midge larvae often form large colonies in the stream channel. 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 sways the larvae, which passively obey the jets and are more like small aquatic plants than living creatures. Only periodically contracting "fans" located near the mouth opening of the larvae indicate that an intense life flows inside these organisms.

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

It is hard to imagine that these legless larvae can move in fast current jets. However, an experienced observer will immediately notice a cone-shaped outgrowth at the anterior end of the body of the larva, the sole of which bears rows of hooks.

The meaning of this outgrowth, called the "foot" of the larva, becomes clear only when the larvae begin to crawl. At the same time, the larva lubricates the nearest part of the surface with a sticky cobweb, attaches itself to it with its thoracic "leg" and pulls up the posterior end of the body. Having fixed the posterior end of the body on the arachnoid platform, the larva releases the thoracic "leg" and, straightening up, looks for a new platform for attachment. Along the entire path of movement, the larva weaves a cobweb thread, on which it is held if it is torn off by the current.

With 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 keep on it in the jets 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 that looks like a cap, from which the pupa sticks out. On her cephalothorax there are branched respiratory 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 suited for piercing the skin of animals. It would seem that bloodsucking for all midges is the most natural way of feeding. However, this is not the case. In some areas, despite the significant abundance of midges, they do not attack animals and humans. Specially designed experiments have shown that female midges can successfully feed on flowers, while the eggs in their ovaries mature normally.

The activity of adult bloodsuckers is also not the same 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) in the tundra are the scourge of humans and animals, and to the south, in the forest-steppe and steppe zones, they are not at all registered as bloodsuckers. It is quite likely that the need for blood feeding arises in adult midges if their larvae developed under unfavorable conditions and did not accumulate sufficient reserves of nutrients. Among 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 anesthetics is injected into the wound. Therefore, the pain quickly disappears and reappears only after the midge sucked blood and flew away. At the same time, substances that prevent blood clotting are introduced into the wound.

The saliva of midges is poisonous. At the injection site, swelling 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 the internal organs begin, which can lead to a quick death.

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

In the USSR, bloodsucking midges are most diverse in the taiga zone. The most malicious bloodsuckers here are tundra midge(Schoenbaueria pusilla), Midge Kholodkovsky(Gnus cholodkovskii), decorated midge(Odagmia ornata) and a number of other species. These midges attack at temperatures from 6 to 23 ° C, and in autumn 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, leprosy. The causative agents of these diseases are transmitted by the female, who has interrupted feeding on a sick animal, during a quick attack on a healthy one. In Africa, midges carry human filaridiasis.

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

In damp and dark rooms, it is often found on the windows of a harmless common butterfly(Psychoda phalaenoides), reaching far to the 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. Starting from April, female mosquitoes, like female mosquitoes, leave their daytime shelters at dusk and attack various mammals, birds, reptiles, delivering many difficult minutes to people. Feeding blood for females is absolutely necessary, otherwise they will not leave offspring. The nectar of flowers, although consumed by mosquitoes for food, fully provides only males, while female mosquitoes are particularly bloodthirsty. Having sucked the blood, the 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 remains, however, at a sufficiently high humidity. In populated areas, mosquitoes develop in spaces under the floor, garbage pits, latrines, barnyards, 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, causative agents of serious diseases can be introduced into the blood - the papatachi fever virus, as well as leishmania, which cause visceral and cutaneous leishmaniasis-pendinus ulcer. Especially dangerous is visceral leishmaniasis, which affects the internal organs of a person - 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 only by 3-4 longitudinal veins. Adult gall midges do not feed and live only 2-3 days, so the prosperity of this family is explained by many useful gadgets that 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 with a magnifying glass, are not afraid of enemies - they are securely hidden inside the gall both from predators and from the adverse effects of the external environment.

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

The gall formation process is very complex. Gall midge larvae do not gnaw on plant tissue; their tiny head and piercing mouthparts are unsuitable for this. The larva acts differently: it secretes specific growth substances onto the surrounding tissues, under the influence of which the plant cells begin to grow rapidly and divide. As a result of close and precise interaction between the larva and the plant, a gall of a strictly defined characteristic shape is formed, so that the type of gall midge can also be easily determined from 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 chrysalis. 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 species is strictly confined to a particular plant species. If the female makes a mistake, the larvae that hatch 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, guided by the subtle features of their odors.

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

Gall midges periodically breed in incredible numbers. Particularly dangerous during periods of mass reproduction are species that damage cultivated plants. Common in Europe, Asia and North America 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. Fields affected by Hessian look as if trampled by cattle.

However, not all groups of gall midges develop in plant tissues. Primitive gall midges still retained a strong connection with their primary habitat - soil, litter, rotting wood. Particularly noteworthy are the gall midges of the genus miastor with a single species - Miastor metraloas. Colonies of larvae of this species number thousands of specimens (Tables 58, 12), and each colony originated from one egg. Miastor is distinguished by the ability, rare 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, tear 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 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 pachyderms(Bibionidae) includes about 400 species, the significance of which in nature lies in the active processing of organic substances entering the soil and improving soil properties. 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 has laid her entire supply of eggs in a given place. Only some dilofus (Dilophus) feed on living plants, the larvae of which gnaw the roots.

Adults appear very amicably during the warm spring months. They often accumulate en masse on flowers, grass, leaves of shrubs or lazily fly in the sun. Peculiar eyes of thick-legged. 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, composed of 9-12 segments. The tibiae of the forelegs are thickened and provided with spines. Often, males and females differ in color. At garden skein(Bibio hortulanus) the male is black, the female is red-brown, but her head, shield and legs are black.

The expressive appearance of slow, clumsy, brilliantly black or brown mosquitoes from families aximiid(Axymyiidae) reminds of those distant times when dipterans 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 a slow and heavy flight, sluggish, clumsy legs, and the whole appearance of an insect, unable to either fly away quickly, or run away, or in any other way 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 they each consist of two sections - the upper, of large facets, and the lower, of smaller facets. The mouthparts of mosquitoes are reduced, and the antennae are greatly shortened, but 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 advanced adaptations in their larvae, which passed to life in wet, rotten wood. They have a large head and strong jaws, with which they cut short passages. 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 tracheae inside. All this is a complex breathing apparatus in wood saturated with water. Other insects could not adapt to life in such an environment, and therefore the aximiids have very few enemies and competitors. But even under these conditions, only 4 species of this family have survived to this day, distributed 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. Thus, the first information about the new family nymphomiids(Nymphomyiidae), whose representatives were also recently found in North America.

white nymphomia(Nymphomyia alba) differs from other Diptera primarily in 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, which increase the total area of ​​the wing. The head of mosquitoes is directed straight forward, the underdeveloped eyes merge not from the upper, but from the lower side, the mouth parts are underdeveloped, and the antennae consist of only 3 segments with a small appendage at the end.

Even more amazing is the white nymphoma chrysalis, 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 is established because insect pupae were found there, but no one has ever seen the larvae themselves.

Among modern Diptera, there were no forms with which nymphomiids could be brought closer. They cannot rightfully be considered long-whiskered Diptera, since their antennae consist of only 3 segments. They also differ sharply from short-haired ones. Only from the Upper Triassic deposits studied in Central Asia are known fossil Diptera with a similar structure. When the nymphomiid larvae are studied, it may be possible to answer the question of which modern Diptera are their closest relatives. So far, this family in the Diptera order occupies a separate position.

Suborder Short-legged Diptera (Brachycera-Orth0rhapha)

These are typical flies with a compact, short body and broad, 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 shed during pupation. The pupa is covered; when the fly emerges, its thorax is ready to crack along a T-shaped line.

horseflies (family Tabanidae) are large blood-sucking Diptera. A female horsefly is capable of taking up to 200 mg of blood in one bloodsucking, that is, as much as 70 mosquitoes or 4,000 midges drink. If we add to this that in the swampy areas during the hot summer months, herds of domestic animals are attacked by tens of thousands of horseflies, the enormous negative significance of horseflies in nature and human economy becomes clear. Their harmfulness is aggravated by the fact that at the time of bloodsucking, horseflies carry 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 along lakes and in river valleys are empty during the summer months, as they cannot be used due to the abundance of bloodsuckers. Even with a moderate attack of horseflies, cows reduce their milk yield by 10-15% and quickly lose weight. Scientists have calculated that in a day the loss of strength in animals that are bothered by horseflies and flies is equivalent to malnutrition 400 G oats per head of cattle. And this is understandable, since the largest of horseflies reach a length of 2-3 cm, their bites are extremely painful and are accompanied by swelling, which is caused by saliva that enters the wound during bloodsucking.

Horseflies are sometimes incorrectly called gadflies. However, it is enough to make sure that a fly caught on an animal has a short, piercing proboscis in order to confidently attribute it to horseflies. The large eyes of horseflies are beautiful - golden, shimmering 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 main features of the life cycle of other bloodsuckers. Males feed exclusively on the nectar of flowers and sugary secretions of aphids, mealybugs, scale insects, as well as sweet juice flowing from injured trees.

Unfertilized females also follow the same diet, however, once fertilized, their aggressiveness has no limits. They attack animals and humans on hot days from morning until sunset, rainflies are active in cloudy weather, especially before rain. Among their victims in the first place are large animals: 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 roundheads, etc. They do not even neglect animal corpses in the first 2-3 days after death, which makes horseflies especially dangerous vectors infections.

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

Horseflies usually do not differ in food selectivity. However, in complex plant communities, for example, in multi-layered tropical forests, individual species complexes are found mainly in one plant layer. In the humid forests of Cameroon, for example, Ethiopian motleys(Chrysops silvacea, Ch. centuriones) stay in the crowns of trees and pursue herds of monkeys.

Females sucking blood quickly digest it. Already after 24 hours, the blood clot in the stomach is significantly reduced, and the absorbed nutrients are fed to the gradually growing 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 is produced on average 3-4 days after bloodsucking. As a result of repeated bloodsucking, female horseflies can go through up to five such cycles, laying over 3500 eggs as a result. The fecundity of different horsefly species can, however, vary greatly.

Eggs are laid on plants, usually above the water of lakes and swamps. The larvae emerging 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 feeding on decaying plant debris, in others actively predatory. Their victims include larvae of other insects, amphipods, earthworms.

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

Brightly colored smaller common lacewing(Chrysops caecutiens), which actually has bright emerald gold eyes. The abdomen of this species has yellow spots at the base. More modestly painted ordinary raincoat(Chrysozona pluvialis), whose wings are distinguished by a complex smoky pattern. In total, there are over 3,500 species in the horsefly family.

long-proboscis(Nemestrinidae) - small family Diptera, distributed mainly in tropical and subtropical regions. Adult flies resemble gadflies, but 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 women 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 trichopsides(Trichopsidea clausa) lay their eggs in cracks in tree trunks or telegraph poles. The fertility 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 penetrates the body of the locust through one of the spiracles and, feeding on the tissues of the host, completes its development by autumn and hibernates. Adult flies appear in spring.

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

large family lion cub(Stratiomyiidae), which includes about 2000 species, is distributed mainly in the humid tropics. Only about a hundred species are found in the northern forests of Eurasia.

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

It is this form that common lion(Stratiomyia chamaeleon), which is often found on flowers. Its black belly with yellow spots, brown chest with a yellow shield and red-yellow legs harmonize well with the bright color of the corollas of flowers, hiding the insect from enemies.

The larva of this fly, which lives in small polluted reservoirs, is peculiar. Its fusiform body, which in an adult larva reaches 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" is a stigmal plate with two holes for breathing. There is also a corolla of long, non-wettable hairs. The larva breathes, hanging by the rear end of the body to the surface of the water. In this case, non-wettable hairs straighten out, stigmas open, and the larva itself is passively held by surface tension forces. Having inhaled, the larva sharply bends, breaking away from the surface film. At the same time, the hairs fold and close the stigmal area. Then the larva slowly sinks to the bottom, where it burrows among the silt and algae, swallowing decaying organic matter. The pupa is formed inside the skin of an adult larva.

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

About 5000 species families ktyrey(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 sharpness of the bulging eyes, deeply separated by the crown, is so great that it is difficult to approach the sitting spikes unnoticed. Although there are no mandibles in their proboscis, other parts of the oral apparatus - maxillae, subglottis and lower lip - form a very perfect stabbing organ. The saliva of ktyri contains a strong poison, from which insects die instantly. A ktyr caught by hand sometimes bites a person. Such a sting is as painful as a bee sting.

The speed and accuracy of the reaction of the ktyrs is surprising: a moment, a short take-off, and the lifeless insect is already sucked out by the ktyr, which has returned to its original place. The aggressiveness of ktyrs is so great that they come out victorious in a fight with such well-armed insects as bees, wasps, horse beetles; the extraordinary voracity of these flies makes them hunt incessantly.

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

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

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

Among Diptera, there are few other groups whose representatives could be compared in speed and dexterity of flight with flies from families buzzed(Bombyliidae). The appearance of most of the buzzers is very peculiar: a short stocky body covered with long dense 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 adaptation for sucking nectar from flowers with a deep corolla, which are inaccessible to many insects. But the buzzers would not have been able to use this advantage if they were not excellent flyers. With amazing dexterity, feeding flies literally hang in the air above the flowers, plunging their proboscis into the nectaries at this time, and, without sitting on the flower, suck out the nectar.

In the modern fauna, the buzzing family is among the flourishing ones and includes about 3000 species.

Predators are like adult flies families pushers(Empididae) and their larvae living 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 pushers is equally well adapted for sucking out insects and for absorbing plant juices. The prey - small Diptera - is captured by the front legs, the hips of which are planted with spikes, and the shins are tightly applied to them, forming strong forceps.

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

greenfinch flies (family Dolichopodidae) - metallic shiny or grayish small diptera with long legs and a laterally compressed body. There are more than 3500 species in the family. Greenfinches are not uncommon in wet 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 subglottis; the mandibles of these Diptera are not developed.

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

Useful greenfinches-medeters(Medetera), whose larvae destroy bark beetles in their passages under the bark of trees. Adult flies of a grayish color are often caught on trunks in the forest.

Suborder Short-eared dipteran (Brachycera-Cyclorhapha)

Typical fly with a short, compact body and broad, 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 mouth hooks are preserved. The larval skin does not shed during pupation, acquires a barrel-shaped shape and hardens, being saturated with special secretions, forming a false cocoon - puparia. The doll is free. When an adult fly emerges, the puparium opens in a rounded line under pressure from the head or frontal vesicle, which in most cases is well developed.

hunchbacks(family Phoridae) are very small nondescript flies with a swollen hump-shaped chest, strong legs, whose hips are thickened. The transparent wings are reinforced along the anterior margin by two thick closely spaced veins; the rest of the veins of the wing are much thinner; there are no transverse veins in the wing.

In anthills there are representatives of the genus platyphora(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 resemble a fly in any way.

Peculiar species live in termite mounds termitaries(Termitoxenia, Termitomyia), which are sometimes distinguished into a separate 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 strongly swollen.

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

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

The way of life of hoverfly larvae is unusually diverse, in contrast to adult flies, which part with nectar-bearing flowers only in order to lay their eggs in a suitable place. Females of some species fly for this to dirty, fetid streams, others rush under the forest canopy, looking for trees with fermenting juice flowing from wounds, still others look for aphid colonies or nests of bumblebees, fourth ones fuss around anthills, etc.

Of the syrphid larvae that develop in water, the larva common bee(Eristalis tenax), which is figuratively called the "rat". The body of this larva is barrel-shaped, indistinctly segmented, with outgrowths - "false legs" - on the abdominal surface. The last three segments of the abdomen form a characteristic "tail" - a breathing 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 are two spiracles, and two thick tracheae pass inside the tube. The fully extended respiratory tube of adult larvae reaches a length of 12-15 cm(Fig. 421, 5).

Rice. 421. Hoverfly flies: 1 - conosirphus (Conosyrphus volucellum); 2 - decorated spherophoria (Sphaerophoria scripta); 3 - bakha (Baccha elongata); 4 - chrysotoxum (Chrysotoxum festivum); 5 - "rat" - larva of the common bee (Eristalis tenax); 6 - larva of the wasp hoverfly (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 will rise, undecomposed organic matter and bubbles of fetid gases will appear. Meanwhile, the bee larva boldly descends into this rotting mess, where it finds abundant food - after all, it leaves the end of the breathing tube on the surface of the water, through which gas exchange occurs. When the larva dives into the deeper layers, it is forced after a while to rise to the surface for breathing. The larva pupates in the soil next to the pond. The pupa is formed inside the larval skin. An adult fly with a brownish chest and a yellow-black spotted abdomen is very reminiscent of 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 be born from mud. Now such a statement can only cause a smile.

Very similar to wasps adult hoverflies from the genus darkstomy(Temnostoma). Their larvae are active wood destroyers of wet stumps and dead trunks. How can these larvae of higher Diptera, which are known to be devoid of a head capsule and gnawing jaws, gouge through wood? To do this, the larvae turned out to have completely unexpected adaptations: the bases of their prothoracic spiracles greatly increased, partially separated and turned into two powerful scrapers, the edges of which were lined with teeth. They scrape wood in the same way that a mollusk - a shipworm - uses the remains of its underdeveloped shell for the same purpose.

However, the most common of the hoverflies are species that live in aphid colonies. It is hard to imagine that the greenish or gray larvae resembling small leeches crawling in colonies of aphids belong to the same family as the "rat", but this is so. It is enough to look at adult hoverflies from the genus sirphs(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 cabbage aphids (Tables 59, 16). One adult larva sucks over 200 aphids per day. Given that the feeding period lasts about 20 days, it can be calculated that each larva will destroy up to 2000 pests during this time, and there are several hundred such larvae in the offspring of only one female. Attracting syrphid to the fields by sowing nectar-bearing flowers, you can successfully fight many harmful aphids.

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

Various species have achieved the greatest success in imitating the stinging hymenoptera. bumblebee, or hairy(Volucella), which are similar to bumblebees both in body shape and in the arrangement of thick fluffy hairs, painted, like in bumblebees, in various colors (Table 59, 8). This similarity arose, in all likelihood, because the bushes 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 garbage.

It is hard to imagine that the sticky resin flowing from injured firs can hide living larvae. But hoverflies have adapted to this habitat. Larvae black chylosia(Chilosia morio) grow only in resin. The whitish body of these larvae is immersed in its thickness, and a short breathing tube is brought to the surface, providing an unimpeded air supply. In the spring, also without leaving the resin, these larvae pupate in a kind of puparia. Completely black hoverflies that have flown out lay their eggs in wounds with fresh resin.

Another 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 painheads look like wasps. The head of the flies is very large, the antennae are often elongated; the proboscis is long, thin, with one or two articulated bends; the body is painted in black, brown and yellow tones.

One of the largest species in the family yellow-footed bighead(Conops flavipes), up to 15 long mm. Her body is black, her head is with yellow spots, and there are also 2-3 yellow bands on her abdomen.

cereal flies (family Chloropidae) have become infamous as pests of grain bread, no less dangerous than the Hessian fly. Almost all representatives of this vast family, numbering over 1300 species, develop on wild and cultivated cereals. Adult flies are common in meadows, forest clearings, on the margins of agricultural fields, where they can be collected in large numbers with an ordinary net. The size of cereal flies does not exceed 3-5 mm, body naked, brilliant black, yellow or greenish; in many species, the chest is on top with longitudinal dark stripes on a yellow background.

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

Most species of grass 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 also found on wild cereals, show a clear preference for cultivated ones.

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

Damage to cultivated cereals by swedish 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 rudiment of the ear, which is destroyed. When the next generation of the Swede flies, the bread is already earing. In this case, the eggs are laid directly in the ear and the larvae eat the grains.

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

speckwings (family Trypetidae) - small or medium-sized flies with a peculiar pattern on the wings characteristic of each species. The drawing is made either with dark stripes and spots on transparent wings, or one or another number of light spots appears on a general dark background. Spotted is often the abdomen. 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 plant tissues. Many species of variegated insects have adapted to the development inside the baskets of composite plants, where they eat away the ovaries of flowers and the receptacle. Having broken large baskets of burdock (Arctium), very often you can find dirty white larvae. orellias(Orellia tussilaginis). There are also larvae of variegated flies in the succulent fruits of cherries, barberries and other plants.

cherry fly(Rhagoletis cerasi) brown-black with a yellow head and shield, legs, with the exception of the thighs, are also yellow. Females lay their 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 insects enter into more complex relationships with plants, causing the formation of pathological growths - galls.

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

Extremely interesting from a biological point of view mining flies (family Agromyzidae). Representatives of this relatively large family, which includes 1000 species, like variegated flies develop in living plant tissues. As with the variegated flies, the nature of the damage caused by the larvae of mining flies is varied. The family includes species that form galls, there are species that inhabit the inflorescences of Compositae or their seeds, pests of grass stems, and even species that have switched to living in tree trunks and branches. But miner species reach the greatest prosperity, the larvae of which eat away vast slit-like cavities in the leaf parenchyma, called "mines".

Most mining 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 mining flies that have switched to feeding on cultivated plants have established themselves as serious pests. Cabbage and other cruciferous plants are harmful phytomysis(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 brilliant black, the legs and sides of the chest are yellow.

In some places in the forest zone, miners from the genus dizygomysis(Dizygomyza) associated with tree species. Willows, birches and some fruit trees are especially affected by them.

Family coasters(Ephydridae), which includes more than 1000 species, reaches its peak in the forest zone. These very small, nondescript flies, painted in gray and black tones, are notable for their biology.

A completely unusual way of feeding larvae oil psilope(Psilopa petrolei) found in California oil wells. Numerous bacteria were found in the oil, as well as in the intestines of the larvae, capable of decomposing paraffin and, presumably, providing the larvae with food. So far, however, it is not clear how the larvae obtain the nitrogenous substances necessary for the synthesis of proteins.

Among the harmful species of the family are barley shore(Hydrellia griseola). The larvae of this small, transparent-winged gray fly develop in mines on the leaves of cereals, including barley, wheat and rice, and sometimes cause significant damage.

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

However, paradoxically, most species of dung flies are not associated with manure. Among them, plant pests are of particular interest, the larvae of which, like the larvae of mining flies, develop in leaf mines or live in the generative organs of plants.

Pests of ears of wild and cultivated cereals (rye, timothy grass) are larvae of ear flies (Amaurosoma).

There are more than 500 species in the family. Many of them are associated with accumulations of decaying plant remains.

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 of towns and cities. Manure, feces, various garbage - these are the garbage where the larvae of the house fly develop - a constant companion of human settlements. The reproduction rate of this species is amazing. At one time, the female lays on average about 100-150 eggs, but with sufficient nutrition, egg-laying is repeated at intervals 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 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) copies.

The larvae of the housefly, like other higher flies, do not have a head. They dilute food by releasing digestive juices onto it - this method of digestion is called extraintestinal. As a result, the entire colony of fly larvae turns out to be floating in a liquefied, semi-digested medium, which they constantly swallow (Table 55). As a result, food is used with amazing economy. In one liter of horse or cow manure or in the same amount of kitchen waste, from 1000 to 1500 fly larvae can develop simultaneously, and up to 4000 in pig manure.

House flies are dangerous spreaders of infections. Each of them, having been on faeces and various kinds of garbage, carries about 6 million microorganisms on the surface of its body and at least 25-28 million in the intestines. And I must say that the pathogenic bacteria in the intestines of the fly are not digested and quite viable stand out. On the flies, typhoid and paratyphoid bacilli, dysenteric bacillus, vibrio cholerae, tubercle bacillus, anthrax spores, the causative agent of diphtheria, and also helminth eggs were found. Therefore, the fight against houseflies is an important link in the overall system of combating human diseases.

Along with housefly larvae, many other species of this family develop in manure and garbage. Larvae house fly(Muscina stabulans) also begin their lives as consumers of decaying plant matter, but then, having become stronger, they begin to feed on the larvae of other Diptera, that is, they become predators. One of the most active predators in manure are larvae. common denticle(Hydrotaea dentipes), which destroy the larvae of houseflies, zhigalok and other species of Diptera.

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

It is often said that by autumn the flies become angry and begin to bite. Such a popular sign arose because it was by autumn that flies-zhigalki appeared, first of all 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 infamous, carrying a special type of trypanosoma - the causative agents of "sleeping sickness", common in Africa. Trypanosomes themselves are constantly found in the blood of antelopes, which are not harmed. Tse-tse fly(Glossina palpalis), having drunk the blood of such an antelope, often then bites a person, passing him trypanos. The disease is expressed in deep exhaustion and usually ends in death.

Another species from the same genus, Glossina morsitans, spreads a similar disease, which, however, affects only animals. Interestingly, in these flies, the larva develops completely 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.

Very serious pests are real flies that develop in living plant tissues. Plants affected by flies usually rot and die. Cabbage and other cruciferous cabbage flies are very harmful, the grayish color of which makes them very similar to houseflies. Their larvae make 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 the death of plants.

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 bubble-shaped cavities in the leaf parenchyma. Lives in stems of cereals winter fly(Hylemia coarctata). Its larvae cause lesions resembling those of a Swede. Larvae spring fly(Phorbia genitalis), also living in the stems of wheat and barley, gnaw out spiral passages in them.

* (Sakharov's locust-eater described below is sometimes classified as a separate family Acridomyiidae or included in the family Anthomyiidae.)

carrion flies(Calliphoridae) - a predominantly tropical family with about 900 species, some of its representatives are common up to the most northern regions. Like many tropical insects, they have a bright color of green or blue tones with a metallic sheen (Table 60).

In tropical countries, closely related species also attack humans. Typically, the females of these species lay their eggs on the earthen floor in the hut where people live, and the larvae then actively infiltrate under 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, which settled 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 teeming with carrion fly larvae.

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

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

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

Larger family gray blowflies(Sarcophagidae), numbering over 2000 species, is poorly represented in the tropics and reaches its peak in the more temperate zones of the northern hemisphere.

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

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

Common in Southern Europe and Central Asia wolffart fly(Wohlfahrtia magnifica), distinguished from other species by the presence of three rows dark spots on a gray belly. The 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 suffering, 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 turned out to be a person in whom they usually caused prolonged suppuration (miasis) 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, bleeding begins from the nose. After removal of the larvae, all these phenomena disappear.

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

Interesting are the adaptations of subcutaneous gadflies to ensure that in strictly defined periods a high number of adults is created in nature, which is important for the successful reproduction of species. Although gadfly larvae fall out of fistulas into the soil at different times, the first pupae formed in spring develop more slowly than those that form somewhat later. Therefore, the vast majority of pupae complete their 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 day, in the temperate zone usually from 7 o'clock. 30 minutes. up to 8 o'clock. 30 minutes. morning. All individuals that have appeared flock from large areas to the same points, constant from year to year, usually to the tops of some hills or mountains, to certain sections of roads, paths, etc. There are significantly more males in these clusters 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 the places of their accumulation.

The females of the hypodermic gadflies laying eggs are very active and for a long time pursue animals in flocks, which turn into a stampede. It is possible to milk cows during the flight of gadflies only when they are standing in the water - gadflies do not attack them at this time. The amount of milk supplied by tired animals is halved, their fatness drops sharply. Northern reindeer husbandry suffers huge losses from subcutaneous gadflies, as the value of skins pierced by larvae is greatly reduced.

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

bull gadfly(Hypoderma bovis) is common in Europe, North Africa and Asia. Females of this species lay their 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 into its walls, then descend into the chest and here they exit to the place of their final development, which proceeds 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. Hairs on thorax yellowish gray in anterior half, black in posterior half; abdomen with black hairs in middle part, its end rufous, and base even paler.

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

Larvae of different species stomach 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 hairline 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 their 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, remaining viable 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 the larvae to the stomach or any other part of the intestine occurs quickly. Here, the larvae are attached to the walls with mouth hooks, feed on the secreted mucus and blood, and when they reach maturity, they are carried out along with the feces. They pupate in the soil.

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

The female lays her 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 emerging 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.

An interesting development cycle of representatives families nasopharyngeal gadflies(Oestridae), Females of all species of this group are viviparous, however, by the time they emerge from pupae, the larvae in the 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 this, a period of active search for host animals begins. Each time, the female sprays several larvae directly into the nasal cavity of the animal, where they develop due to mucous and bloody pathological secretions. Together with the larvae, the female also sprays out a certain amount of liquid. The larvae are very sensitive to desiccation, and even before the evaporation of this liquid, they must get on the mucous membrane of the nasopharynx. Some animals, such as deer, during the attack of gadflies inhale dust and fine sand, thereby drying the nasal cavity and to some extent protecting themselves from larvae.

In conditions temperate climate young larvae of gadflies overwinter, in spring and summer their development is completed. Adult larvae exit through the host's nostrils.

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

Great harm to livestock 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 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 spread 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 whirlwind” is observed - a disease in which 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. Enormous funds are spent annually on the fight against these Diptera, however, the fight against gadflies is effective only when it is carried out according to plan and on time. large territories. In the USSR in the last decade, as a result of the use of a complex of chemical and preventive measures struggle, significant progress has been made 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. Tahini are sun-loving insects, in summer they are most often 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 tahini are characterized by a twilight period of activity.

Although fertilization occurs in the first hours after the appearance of females from puparia, eggs are not laid immediately. In various types of tahini, it takes from 8 to 25 days for the eggs to ripen 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 monophage species that develop exclusively at the expense of any one animal species. The majority of tahini successfully attaches their offspring to a large number of different hosts, which, however, belong to one family or order, i.e., are more or less related. The larvae that hatch from eggs swallowed with food pierce the intestinal wall and reach certain organs with the hemolymph current, where they develop. In some species, the larvae are located in the supraoesophageal ganglion, in others they penetrate the salivary glands or linger in the muscle tissue.

Growing up, the larvae begin to experience difficulty in breathing and usually attach with the posterior end of the body to one of the tracheal trunks of the host so that the spiracles of the larvae emerge into the lumen of the trachea.

The larvae that have successfully entered the body of the host 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 into the tissues of the host, causing their complete digestion. Having finished feeding, adult larvae most often exit through the integument of the body and pupate in the soil.

Bloodsucker eggs mature in the body of the female, and larvae hatch from them there. The food of the larvae is the secretion of special adnexal glands. Eggs in the ovaries are formed alternately, and therefore the female feeds one larva in each subsequent period of time. The larva grows rapidly on nutritious food and leaves the mother's body only to pupate immediately after climbing into the soil. Therefore, bloodsuckers and some other Diptera, which give birth to larvae ready for pupation, are often combined into a group of "puppets".

Bird bloodsuckers can generally live successfully on many bird species. When birds come into contact with each other, flies often change hosts. The species composition of bloodsuckers on birds of prey that prey on other birds is especially diverse: at the time when the predator eats its prey, all the bloodsuckers living on it move to a new host.

In bloodsuckers of bats, two ways of attaching the born 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 emerging from the puparium independently searches for the owner. Only a few species attach the born larvae to the fur of bats.

In total, there are about 150 species in the family. All of them are relatively small - length common bloodsucker bats(Nycteribia pedicularia) 2-3 total mm. Despite some external similarities, bat bloodsuckers are not considered closely related to the Hippoboscidae family discussed above. They are thought to have originated independently of dipterans, which originally developed on the refuse of bats and then adapted to feeding on their blood.

Superclass: Insecta = Insects Linnaeus, 1758 = Insects

Order: Diptera = Diptera (mosquitoes and flies);

Family: Diopsidae \u003d Diopsida (Stalked-eyed)

Family: Culicidae = Blood-sucking mosquitoes [real]

Family: Mycetophilidae Winnertz, 1863 = Mushroom mosquitoes

Family: Ceratopogonidae = Biting midges (lecture)

Family: Simuliidae = Midges (lecture)

Family: Muscidae = Real flies

Family: Hippoboscidae = Bloodsuckers

Family: Asilidae = Ktyri

Family: Hippoboscidae = Bloodsuckers

Family: Gasterophilidae = Gastric gadflies

Family: Hypodermatidae = Subcutaneous gadflies

Family: Glossidae = Tse-tse flies

Family: Phoridae = Humpbacks

Order: Diptera (Mosquitoes and flies)

The Diptera order (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 around the planet. Diptera's mouth is designed in such a way 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 named so because only the first pair of wings is developed and used in flight.

The malarial mosquito, when landing on something, raises its abdomen, the common peeping mosquito keeps it parallel to the surface or even lowers it a little. The larvae of the squeaker mosquito hang vertically at the surface of the water, head down, and the malarial mosquito hangs 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, representatives of this family can be found, 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 juice. And in bloodsuckers, only females feed on blood, males - only plant sap.

By autumn, all males of the common mosquito die, only females overwinter in different cracks. In the spring they wake up and rush 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 the mosquito female could not drink blood before laying eggs, then she lays fewer eggs - 40-80.

Soon the larvae hatch. 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 upside down near the surface film of water. But a little danger, they immediately go down. Then they pop up again. They feed on microscopic algae, the remains of dead animals and plants, filtering up to a liter of water each day.

After about three weeks, mosquito larvae pupate. The pupae are lighter than water and float to the surface. They already have eyes, however, still hidden under the covers of the chrysalis. But these covers are transparent, and sudden illumination frightens mosquito pupae - they all immediately sink into the depths. But they soon resurface. Pupae do not eat anything: their mouth organs turn from filtering into piercing-sucking. Other transformations quickly take place, and a few days later a long-legged winged mosquito appears from its bursting 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 rising and falling, the mosquitoes seem to be dancing in place. The smell emitted by the special glands of the mosquito in flight is amplified thousands of times when they gather in a flock. Dancing, mosquitoes scatter it in all directions, and, attracted by this smell, females rush to dance from all sides. Sometimes they also gather in a flock, which winds just below the dancing males. Suddenly, one or another female breaks out of the flock and soars up into 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 randomly? He hears her! Hear the beating of her wings. They oscillate five hundred times per second, and in unison with their oscillation, the male's antennae begin to vibrate. 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 the sexually mature, the immature one that flaps its wings in a different rhythm, just like male mosquitoes. Therefore, mosquito antennae, tuned to a certain frequency of oscillation, do not respond to the flapping of the wings of other males in the flock.

The old question—whether all female mosquitoes must first drink blood in order to lay mature eggs—has not been definitively settled. Apparently, for some subspecies of common peeping mosquitoes, this condition is not necessary. And hungry females develop eggs, only the fecundity is much less than that of sucking blood.

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