Diptera are a detachment of invertebrate animals from the class of insects, which are characterized by the presence of only one pair of wings and complete metamorphosis. The order unites more than 150 families and over 100 thousand species of dipterans. Everyone knows such representatives of this broad group as midges, flies, mosquitoes, horseflies.
These insects are widespread on Earth from the tundra to the deserts of the tropics. Diptera have been known since the Jurassic period.
They are not social insects, but they can gather in flocks, attracted by the smell of food, convenient locations of mating or resting places. The vast majority of these insects live solitary lives for most of their lives.
The development cycle with complete transformation includes the stages of egg, larva, pupa, and adult. The larvae have a worm-like body, lack legs, and instead of them there may be unsegmented protrusions on the abdominal segments. There is a gnawing type mouthparts. After a certain time, the larvae transform into covered pupae.
Reproduction . Diptera are characterized by pronounced differences in the anatomical and physiological structure of larvae and adults. Thus, the life span of the larva significantly exceeds that of the imago; it is the larva that is the main feeding stage. The imago of some species may not need food at all (botflies). The main functions of adults in the life cycle are reproduction and dispersal. Under favorable conditions, dipterans develop from four to ten generations per year.
Structure of imago Diptera . Dimensions range from 2 mm to 5 cm. Like all insects, the body has bilateral symmetry, divided into a head, chest with three pairs of limbs and abdomen. The head is round in shape with large compound eyes on both sides. The oral apparatus in most species is of the sucking type; it can be sucking-licking (flies), piercing-sucking (mosquitoes), and sometimes underdeveloped (in non-feeding adult gadflies).
Three pairs of legs are attached to the chest, and the paws have claws and suckers, with the help of which dipterans are able to crawl along vertical surfaces.
Internal structure of Diptera . The fluid medium of the body is hemolymph, which is an analogue of blood in the circulatory system of higher animals. The circulatory system is not closed, the hemolymph freely washes the internal organs in the body cavity, then collects in the vessels. The function of the heart is performed by a thickened dorsal vessel in the back of the chest. The respiratory system is the trachea, and gas exchange takes place in the abdomen, where many tracheae are located next to the aorta. Characterized by the presence of a brain.
Brief taxonomy of the order Diptera, or mosquitoes and flies:
Family: Agromyzidae = Mining flies
Family: Anthomyiidae = Flowerworts
Family: Asilidae = Ktyri
Family: Bombyliidae = Buzzers
Family: Braulidae = Bee lice
Species: Braula coeca = Bee louse
Family: Calliphoridae = Calliphoridae, blowflies
Family: Ceratopogonidae Newman, 1834 = Midlings
Family: Chaoboridae = Thick-mouthed mosquitoes
Family: Chironomidae = Bell mosquitoes
Family: Culicidae Meigen, 1818 = Blood-sucking mosquitoes [true]
Family: Drosophilidae = Fruit flies, fruit flies
Family: Empididae = Pushers
Family: Gasterophilidae = Gastric botflies
Family: Glossidae = Tsetse flies
Family: Hippoboscidae = Bloodsuckers
Family: Hypodermatidae = Hypodermatidae
Family: Muscidae = True flies
Family: Mycetophilidae = Fungus gnats
Family: Oestridae = Nasopharyngeal botflies
Family: Phlebotomidae = Mosquitoes
Family: Psychodidae = Phlebotomus
Species: Phlebotomus papatasi Scopoli, 1786 = Patataceous mosquito
Family: Sarcophagidae = Gray meat flies, sarcophagids
Family: Scatophagidae = Dung flies, scatophagids
Family: Simuliidae = Midges
Family: Stratiomyidae = Lionflies
Family: Syrphidae = Hoverflies
Family: Tabanidae = Horseflies
Family: Tachinidae = Tachinidae, hedgehog flies
Family: Tanyderidae = Tanideridae
Family: Tanypezidae = Long-legged
Family: Tephritidae = Piedwings
Family: Tipulidae = Long-legged mosquitoes
Family: Trichoceridae = Winter mosquitoes
Brief description of the squad
Diptera insects are the most highly organized order, the representatives of which have one (front) pair of membranous transparent or colored wings. The hind wings are vestigial and transformed into halteres. Mouth parts piercing or licking. According to the structure of the cows, they are divided into two suborders: long-whiskered ( Nematocera), which include mosquitoes, midges, mosquitoes, long-legged mosquitoes, bells, or bloodworms, gall midges, etc., and short-whiskered mosquitoes ( Brachycera), including horseflies, flies, gadflies, tahins, tyres, bloodsucker and many others. Transformation complete. The larvae are legless and often (in flies) without a separate head. Pupae are free or barrel-shaped.
Its larvae are found on sea coasts and in all types of inland water bodies of all landscape zones - flowing and stagnant, cold and warm, weakly and highly mineralized, clean and heavily polluted. They inhabit all parts of water bodies, ranging from the moist soil of the shores, aquatic plants and the surface film of water down to depths of several hundred meters.
Predatory or herbivorous forms. There are a number of specialized bloodsuckers (midges, mosquitoes, horseflies, some flies - tsetse flies, bloodsuckers and some others). Larvae of many forms live in water (mosquitoes, midges, etc.). In many flies they develop in rotting organic matter, which they also feed on. The digestive enzymes secreted by the larvae promote the rapid decomposition of organic residues and transform them into a semi-liquid state. This “food gruel” is absorbed by the larvae. The larvae of a number of dipteran species lead a parasitic lifestyle (botflies, tachynes).
The larvae of aquatic dipterans vary in shape, most often elongated cylindrical, worm-shaped, with a narrowed anterior or both ends. Sometimes only the anterior end is narrowed, and the posterior end is widened. Some have a widened anterior end, a weakly widened anterior end, and a club-shaped thickened posterior end.
Body may be flattened dorsoventrally. Body segments are smooth or with projections of various shapes.
The most characteristic feature of dipteran larvae, which distinguishes them from all other orders of insects, is the absence of true articulated thoracic legs articulated with the body. The larvae are either legless, or the latter are functionally replaced by soft outgrowths - pseudopods, often equipped with hooks or spines, crawling ridges - special thickenings of the body wall bearing transverse rows of tubercles and spines. Some larvae have pseudopods equipped with suckers. The larvae swim, quickly and alternately moving the anterior and posterior ends of the body, with quick jerks due to sharp bends of the abdomen or smooth wave-like, serpentine movements, which is very typical for most larvae of the subfamilies Palpomyunae serves as a good distinguishing feature from all other families.
The body of the larvae is most often clearly segmented and consists of 3 pectorals, sometimes merging into a single complex, and 8-9 abdominals. Sometimes secondary segmentation of the body is observed.
The cuticle of the larvae is transparent, except in cases where it is densely covered with various kinds of outgrowths or impregnated with lime and other substances.
Larvae Diptera are often colored. The color depends on the pigment located in the parietal or internal fat body. The external pigment may be diffuse or concentrated into spots and stripes. Sometimes the color depends on the pigment located in the hemolymph.
In dipteran larvae, all transitions take place from a fully developed, sclerotized, often pigmented head capsule to its complete reduction and replacement with a pseudocephalon (false head). In a number of forms, the head is partially or almost completely retracted into the prothoracic segment. The main parts of the oral organs are mandibles and maxillae. The first are well developed, sclerotized.
Of great importance are the various formations around the posterior pair of stigmas in meta- and peripneustic forms, which together represent the stigma plate, the structure of which is often a very good systematic feature. The stigma plate serves aquatic larvae breathing atmospheric air to overcome the elasticity of the surface film of water when establishing contact between the respiratory system and atmospheric air and to maintain the larvae on the surface of the water. In larvae leading a burrowing lifestyle, it also serves as a support when moving forward. It usually consists of several lobe-shaped processes surrounding the stigmata and often giving the plate a star-shaped shape. In some larvae these processes are functionally replaced by hairs. When the larva is on the surface, the plate with hairs lies open on the surface film. When immersed, the stigma larvae are drawn inward, the lobes or hairs are bent, forming a cavity under the stigmas into which an air bubble is captured.
In addition to the respiratory function, the tracheal system often also performs a hydrostatic function.
Diptera, as well as Hymenoptera, play an important role in nature and human economic activity. The negative value of Diptera is great. A number of forms harm plants, including agricultural crops.
Mosquitoes (fam. Culicidae) have long antennae and piercing-sucking mouthparts. Male mosquitoes feed on nectar or plant sap, and females of many species feed on the blood of humans and animals. Larvae and pupae live in stagnant bodies of water. Malaria mosquitoes ( Anopheles) spread malaria.
Mosquitoes ( Phlebotomus) - small dipterous insects whose body length usually does not exceed 3 mm. The body is covered with hairs. Males suck plant juices. Females feed on the blood of humans and warm-blooded animals. Very numerous in tropical countries. In the CIS they are found in Crimea, Central Asia, and the Caucasus. Mosquito bites are very painful and cause itchy skin. They spread pathogens of a number of human diseases: leishmaniasis, summer influenza (a disease like temporary fever).
Midges (fam. Simuliidae) are well known to the inhabitants of the taiga. They make up the bulk of the midges - huge clusters of small blood-sucking insects. Midges, the length of which does not exceed 5 mm, are distinguished by a short body with a raised front breast with a hump. Their antennae are shorter than those of mosquitoes, but longer than those of flies. Only females feed on the blood of warm-blooded animals and humans. Midges transmit pathogens of a number of diseases to humans and farm animals.
Gall midges (family Cecidomyiidae) include a large number of species of small mosquitoes with an elongated body, long legs and thin wings with few longitudinal veins without transverse joints. Gall midge larvae, settling in plant tissues, often cause the formation of growths - galls. Some species of gall midges cause significant damage to agricultural plants. Such, for example, is the Hessian fly (or rather, a mosquito) ( Mayetiola destructor), the larva of which lives in the stems of cereals.
Flies (fam. Muscidae) are distinguished by a wide flattened body, a hemispherical head with short antennae. The common housefly is dangerous because it carries the eggs of parasitic worms and pathogens of various diseases on its legs and proboscis. Equally dangerous as disease spreaders are large green and blue carrion flies.
Horseflies (fam. Tabanidae) - large or medium-sized blood-sucking flies with huge iridescent eyes. Horsefly bites bother livestock. They are carriers of anthrax.
Gadflies (family Oestridae) are among the important parasites of farm animals. They differ from horse flies by their short, hairy body and small eyes. Adult gadflies have underdeveloped oral organs, and they do not eat anything during their short lives. Bovine gadfly larvae ( Hypoderma bovis) and cattle gadfly ( Hypoderma lineata) parasitize the body of cows and bulls, accumulating under the skin in the last stages of their development. Sheep botfly larvae ( Oestrus) live in the nasal cavity and frontal sinuses of sheep, causing false “whirl”.
Gastric gadflies (fam. Gasterophilidae) are similar to skin gadflies. Their larvae parasitize the intestines and duodenum of horses and donkeys, often causing severe inflammation of the mucous membrane of these organs. Adult gadflies lay eggs on horses' fur, from where they are licked off by the owner.
Botflies cause great damage to livestock production. These are quite large hairy flies that lead a free lifestyle and visit their hosts (horses, cattle, sheep, etc.) only to lay eggs or larvae. The larvae are thick, somewhat narrowed in front, hard, usually with spinous rings, with a pair of spiracles strongly chitinized along the edges at the posterior end and with another pair of spiracles near the anterior end of the body. The larvae settle in the stomach, under the skin, in the nasopharynx, frontal and maxillary sinuses.
A serious pest is the Wohlfarth fly ( Wohlfahrtia magnified), which lays larvae - it is viviparous - in the nose, ears, anus of mammals, as well as on wound and ulcerative surfaces.
The larva feeds on living tissue, then emerges and pupates in the ground. There are known cases of human infection with Wohlfarth fly larvae. Flies lay larvae mainly on people sleeping in the open air during the day. The larvae live in a person's ears, nose, frontal sinuses, gums, eyes and cause severe suffering.
The positive significance of dipterans is also very significant, many of which are important pollinators of flowering plants. Predatory (ktyri) and parasitic (tachyna) destroy harmful insects. Larvae of bell mosquitoes, or bloodworms (family. Chironomidae), serve as food for many
Order: Diptera (Flies and mosquitoes)
Phylum: Arthropoda von Siebold et Stannius, 1845 = Arthropoda
Order: Diptera = Diptera (Flies and mosquitoes)
Diptera lifestyle
The structure of the legs of dipterans is closely related to their lifestyle. Agile, fast-running flies have short, strong legs. Mosquitoes, which usually hide among vegetation during the day, have long limbs adapted for climbing among the tangle of grass stems 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, dipterans can move freely on a completely smooth surface. Ingenious experiments have proven that in flies these pads serve not only for movement, but are additional taste organs that signal the edibility of the substrate on which the fly has landed.
If a hungry fly is brought to a sugar solution so that it touches it with its paws, the fly extends its proboscis to suck. When the sugar solution is replaced with water, the fly does not react in any way. 
Both the chest and abdomen, which in dipterans consist of 5-9 visible segments, often have a characteristic color and are lined with hairs and setae. The arrangement of these setae is often used as a character to distinguish individual families, genera and species of the order. The idea of dipteran larvae as whitish, legless and headless “worms” swarming in manure and garbage dumps does not at all reflect the true diversity of their forms and is based on the most superficial acquaintance with the order. First of all, it should be emphasized that the larvae of all long-whiskered dipterans have a well-developed head and are often equipped with strong jaws, with the help of which the larvae feed on plant roots or rotting organic matter. The only exception is the rare family of long-whiskered dipterans - hyperoscelidids (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, whose entire oral apparatus is usually represented by only two sclerotized hooks.
The loss of the head capsule, so characteristic of the larvae of higher dipterans, is associated with the development of a unique method of digestion in them, which is called extraintestinal. With this type of digestion, food is first digested outside the larva’s body under the influence of the digestive juices it secretes, and only then is it swallowed and assimilated. The body shape of the larvae is varied. It is usually worm-shaped, but sometimes it is so unusual that it can baffle an inexperienced taxonomist. Very bizarre, for example, are the flat larvae of Deuterophlebiidae, a small family common in the Altai, Tien Shan, Himalayas and Rocky Mountains of North America, living in fast mountain streams. Each segment of the larvae bears a long outgrowth on its sides with a sucker at the end. By alternately moving these outgrowths, the larvae are able to slowly move along the stones at the bottom of the fastest streams. They completely lack a tracheal system - a rare case not only in dipterans, but also in insects in general, and they breathe using anal gills.
Very noteworthy are the larvae of ptychopterids (family Ptychopteridae), developing in fresh water bodies. They have a well-developed head, dense integument, equipped with dense rows of spines, and a long respiratory tube formed from the last two segments of the abdomen. There are spiracles at the end of the tube, and two respiratory filaments are attached to its middle part. The 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 underwater parts of plants in search of food. Very interesting are the slug-like larvae of mosquitoes of the genus Ceroplatus (Ceroplatus family Ceroplatidae), which are found openly on the surface of fungi and mold. They have a rare ability among dipterans to emit weak phosphorus light in the dark, 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 dipteran larvae is the absence of thoracic (true) legs. The absence of legs in fly larvae in some cases is compensated by the development of various body outgrowths, reminiscent of the “false legs” of butterfly caterpillars. With the help of these outgrowths, the larvae can move relatively quickly on the surface of the substrate. Such larvae are known, for example, in the snipe family (Leptidae), which has more than 400 species. Most of them have worm-shaped larvae and do not differ in appearance from housefly larvae. But in the larvae of the ibis fly (Atherix ibis), which live among stones at the bottom of fast-flowing rivers, on each body segment there is a pair of “false legs” equipped with hooks, which serve as perfect organs of movement. In an abundant food substrate, dipteran larvae are found in large clusters. Common places for the mass development of larvae of higher flies are decomposing animal corpses, garbage dumps, latrines, etc.
Fungus gnat larvae (Mycetophilidae) bring a lot of frustration to mushroom pickers. In most cases, it is their long white larvae with a black head that swarm on the fractures of “wormy” mushrooms, making them completely unsuitable. True, fungus gnats cannot be considered exclusively inhabitants of mushrooms; some of their groups are associated with rotting wood, plant debris, etc., where they also form large colonies. Larvae of leaf mosquitoes (family Sciaridae) are also found in large concentrations. In some cases, when food is scarce, these masses of larvae may undertake mass migrations. The larvae of the war mosquito (Sciara militaris) are grouped into a long ribbon up to 10 cm wide, which, slowly wriggling, moves in search of a favorable place. The appearance of such “snakes” aroused superstitious fear among people; they were considered a harbinger of crop failure, war and other disasters. Hence the name “military” mosquito. The process of transformation of an adult larva into a pupa in Diptera has its own characteristics. Typically, in insects with complete metamorphosis, after a pupa has formed under the integument of the larval skin, these integuments are shed and the pupa is completely released.
Long-whiskered dipterans 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 like an unnecessary shell, but, on the contrary, hardens, takes on 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. This biological feature is the basis for identifying in the order Diptera, in addition to the suborder long-whiskered, or mosquitoes (Nematocera), two more suborders: short-whiskered straight-stitched dipterans (Brachycera-Orthorrhapha), which do not have a puparium, and short-whiskered round-stitched diptera (Brachycera-Cyclorrhapha), developing with puparia. It is interesting that the larvae of some groups of dipterans, although they do not form a typical puparium, still pupate inside the larval skin. Among long-whiskered dipterans, this method of pupation is typical for the small family of scatopsids (Scatopsidae), numbering about 130 species, and for a few species of the family of gall midges (Cecidomyiidae), such as the Hessian fly and some others. Lionfly larvae pupate from short-haired straight-sutured dipterans inside a slightly modified larval skin.
The adaptability of dipterans to various living conditions is unusually wide. Their larvae have mastered a wide variety of habitats: fast streams and stagnant waters, clean, transparent bodies of water, including seas with salt water, and fetid sewers, thick soil, various rotting plant substances entering the soil, tissues of living plants and, finally, , the body cavity of insects and other invertebrate animals, as well as the intestinal tract, subcutaneous tissue and respiratory tract of vertebrate animals, and in some cases of humans. Diptera larvae lead a hidden lifestyle and are incapable of long-term movements. To place their offspring in suitable conditions is the task of adult flies, which are therefore good flyers. Many of them have interesting adaptations that increase the survival rate of the larvae. It is enough to recall the birth of live larvae, common among higher dipterans, and in some cases the feeding of the larvae with secretions of special glands, when the larva leaves the mother’s body when it is already fully grown. However, it is usually not adult flies that feed their larvae, but, on the contrary, the larvae store the nutrients necessary for the life of the adult phase. There are often cases when adult dipterans live solely on the nutrients that the larva has accumulated and do not feed at all. Other species only need to drink water, flower nectar, or sweet sap flowing from wounded trees. But not all adult dipterans are so harmless. Mosquitoes, horseflies, biting midges, midges, sand flies are annoying bloodsuckers. However, only females suck blood from them, while males are completely harmless. If the females of these dipterans do not drink blood, they will remain infertile. 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.
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You will learn who the representatives of dipteran insects are from this article.
Diptera: representatives
Diptera insects representatives of the order invertebrates, class of insects. They are distinguished by the presence of a fashionable pair of wings and complete metamorphosis. Today we know more 100,000 species.
Representatives of Diptera- flies, mosquitoes, midges, horseflies. They are distributed everywhere from the tundra to the deserts of the tropics. According to archaeological excavations, dipterans lived back in the Jurassic period.
They are not social insects; they rarely gather in flocks - only for resting, mating and in case of a large amount of food. Most lead a solitary lifestyle.
What insects belong to the order Diptera?
Representatives of dipterans are united into several groups: butterflies; mosquitoes and biting midges; centipedes; lions; thicklegs and fungus gnats; stem beetles; dung and house flies; humpbacks; hoverflies; horseflies; balls; gadflies and tahini. The order is Diptera representatives, which are widespread in nature:
We hope that from this article you learned who the representatives of dipterous insects are.
The position of insects in the animal kingdom
Entomology is the science of insects (from the Greek words entomon - insect, logos - science). Insects constitute the class Insecta, a type of arthropod (Arthropoda) animals. Insects are characterized by such characteristics as the presence of one pair of antennae, the conduct of a terrestrial lifestyle and the tracheal respiratory system as an adaptation to it. Based on these characteristics, insects are classified into a separate subphylum of trachea-breathing insects (Tracheata). Insects are often also classified as a subtype of jawed, or mandibular (Mandibulata), which are characterized not only by the presence of antennae, but also by the transformation of the three pairs of oral limbs following the antennae into oral organs, of which the upper jaws, or mandibles, are especially strongly developed.
The class of insects is unusually diverse and the number of species included in it exceeds the total number of species of other animals and plants. Currently, about 1 million species of insects have been identified, but in reality their number can reach up to 1.5 million. Each species has a unique combination of properties and characteristics, i.e. has only its own specificity. And insects have achieved an infinite variety of morphological and biological features, adaptive features, and connections with other organisms. Organic nature has embodied in the world of insects the largest number of life forms and the largest number of forms of participation in the cycle of substances.
Insects can be found everywhere: on plants and in the soil, in the air and water bodies, high in the mountains, in the zone of eternal snow and in sultry deserts.
The importance of insects in nature and human life
The role of insects in nature, in the economy of society, and in people’s lives is no less diverse. Based on fossil remains, it was possible to establish that the most progressive groups of insects developed in parallel with higher flowering plants, which for many of them served as a source of food, moisture, and sometimes shelter. In turn, insects pollinate up to 80% of plants. Often, due to a lack of pollinators, the yield of fruits and seeds of such valuable crops as apple, pear, buckwheat, sunflower, clover, and alfalfa is noticeably reduced. From insects, a person receives honey, wax, royal jelly, propolis (honey bees), silk and tussock (mulberry, oak silkworms), shellac (lacquer bug), and the coloring matter - carmine (cochineal bug).
A large group of insects is involved in soil formation. Together with mites and annelids, they destroy litter and plant litter, loosen the soil with their moves, promote better ventilation and enrichment with humus. The destruction of animal corpses and excrement, carried out by representatives of another faunal complex of insect species, is of great sanitary importance. Thus, due to the lack of insects that decompose manure, pastures in Australia began to die, and only the importation and acclimatization of dung beetles made it possible to improve the situation.
Along with the positive ones, the negative consequences of insect activity for humans are also very significant. Many species of insects that feed on plants can reach high numbers and cause serious damage to agricultural crops and forests.
There are many species whose diet is associated with humans and vertebrates. Many bloodsuckers not only bother people with their bites, but also carry pathogens of dangerous diseases. Thus, lice transmit typhus and relapsing fever, fleas transmit plague, malarial mosquito transmits malaria, tsetse fly transmits sleeping sickness, etc. Farm animals suffer from gadflies and horse flies.
In connection with such a diverse significance of insects, entomology, in the 18th century. separated from zoology as a separate branch of knowledge, it has now turned out to be divided into a number of independent scientific disciplines - general, agricultural, forestry, medical, veterinary entomology, beekeeping and sericulture.
Order Diptera or Flies and mosquitoes (Diptera)
Among the 33 modern orders of insects, the order Diptera occupies one of the first places in terms of the number and diversity of representatives, second only to beetles, butterflies and Hymenoptera in this regard. To date, 80,000 species of this order are known. 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 order Diptera. In the vast order of Diptera there is a huge variety of body sizes, shapes and colors. The length of some gall midges is only 0.4 mm with a wingspan of just over 1 mm. Some cetaceans reach a length of 50 mm, and the wingspan of individual centipedes exceeds 100 mm.
Rice. 1. General view of Diptera
1 - long-legged mosquito Tipula lunata; 2 - mosquito Megarrhinus Christophi; 3 - Bombylius buzzed; 4 - hoverfly Spilomia digitata.
However, despite the large number of species and diversity of dipterans, they all share common characteristics. Typically, adults have only one pair of membranous wings, rather thin integuments, 5-segmented tarsi, a licking or sucking mouthpart (proboscis) and well-developed compound (compounded) eyes. Development occurs with complete transformation (metamorphosis), i.e. a larva hatches from the egg, which, after several molts, turns into a motionless pupa, and from the pupa an adult insect (imago) is born. Diptera larvae, unlike caterpillars, are always legless.
Although large swarms of Diptera are often observed, they are not social insects such as termites, bees and ants. On the contrary, most of them live alone, at least for most of their lives. However, many dipterans gather in a kind of swarms, attracted by the smell of food, a convenient place for resting or mating.
Diptera can fly to the light together with insects of other species. Mosquitoes, bells and centipedes swarm closer to dusk, usually over bushes, paths or other landmarks, near which the swarm, if frightened off, gathers again. Such groups consist mainly of males; It is believed that the sound of their wings attracts females with their characteristic tone. In experiments, by producing sounds similar to the squeaking of female mosquitoes of certain species, it was possible to induce swarming of the corresponding males. Clusters are especially characteristic of blood-sucking dipterans (gnus). If a species is active mainly in the dark, it is called nocturnal, if in the light it is called diurnal; An intermediate crepuscular group is also distinguished.
Hanging flight is observed in different species of Diptera, but is especially developed in hoverflies and buzzers. Representatives of these families fly quickly and maneuver well in the air. You can often observe how they hover motionlessly in place, intensively working their wings, and then suddenly disappear from view.
Features of the biology of Diptera
Like other higher insects, the life cycle of dipterans is complex and includes complete metamorphosis. The eggs of most species are oblong and light-colored. They hatch into larvae that are usually elongated, roughly cylindrical, soft-bodied and legless. In most cases, the hard parts of their heads 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 varies among dipterans, but usually there are two or three. This is followed by the pupal stage. In some dipterans it is formed inside the larval skin, which turns into the so-called. "puparium". Eventually the shell of the pupa ruptures, and an adult insect (imago) is born.
Let us consider the development using the example of a representative of this order - the common mosquito (Culex pipiens)
The life cycle of a typical mosquito from the genus Culex begins with the laying of eggs on the surface of the water by the female, glued together into a “raft”. At optimal temperatures, the larvae hatch in 1–2 days. They live in water, but breathe atmospheric air through a breathing tube extending from the back of the abdomen.
Fig.2. Life cycle of the common mosquito (Culex pipiens)
About a week later, after 4 molts, the larva turns into a pupa. It is capable of active swimming, but stays mainly near the surface of the water. Eventually its dorsal coverings burst and the adult insect emerges. Under favorable conditions, the full development cycle takes no more than two weeks.
Rice. 3. Developmental stages of Culex pipiens
Other species of mosquitoes develop according to the same pattern, varying only in details. Thus, female malaria mosquitoes (genus Anopheles) lay eggs one at a time, without gluing them into “rafts,” and their larvae are not held at an angle to the surface of the water, but almost horizontally.
Etiology and epidemiology
Mass reproduction of flies in food supplies in homes, food processing plants, grocery stores and food outlets can lead to intestinal myiasis when fly larvae and their eggs are ingested with food.
Clinical picture and pathogenesis
Infections carried by Diptera
Blood-sucking dipterans are carriers of vector-borne diseases, such as malaria, sleeping sickness, onchocerciasis and other filariasis, leishmaniasis, etc. The adults of many flies are mechanical carriers of pathogens of various bacterial diseases and helminthiases. Flies mechanically transmit pathogens of intestinal infections (cholera, dysentery, typhoid fever), tuberculosis, diphtheria, paratyphoid fever, anthrax and protozoan cysts. There are up to 6 million bacteria on the body of a fly, and up to 28 million in the intestines. Cereal flies from the genus Hippelates, feeding near the eyes, introduce bacteria into them that causes acute epidemic conjunctivitis.
Veterinary dipterosis. Diptera and their larvae greatly harm agriculture, causing diseases in domestic bees, large and small cattle, horses, damaging food supplies, carrying pathogenic organisms, etc.