Class insects, order Diptera. Mosquitoes

If everyone remembers school course zoology, then he will remember the information that the malaria mosquito belongs to the genus of mosquitoes, including more than 150 species. And malaria mosquitoes are spread across all continents globe except forever icy Antarctica. This type The mosquito is called anopheles. Its largest population is observed in Africa, which can be explained by the most favorable climatic conditions. On the designated continent, in South-East Asia and central part South America There is the highest mortality rate from a disease such as malaria. And the causative agent of malaria is precisely this type of insect. The number of people who die from malaria every year in these territories is about a million people.

The Anopheles mosquito itself does not pose a threat to humans. It only acts as a distributor of a serious fatal disease, which occurs through a mosquito bite.

Difference between malaria mosquito and common mosquito

Visual perception and lifestyle do not differ significantly between the common mosquito and the malaria mosquito. However, some differences can still be found.

So what does a malaria mosquito look like? The adult specimen of the malarial species has much longer legs than those of the common mosquito. This difference is most pronounced in the hind legs. The female malaria mosquito is endowed with jointed tentacles located on the head. And the length of these tentacles is no less than the length of the proboscis. What can't be said about females? ordinary type mosquitoes The length of the tentacles of the female common mosquito is only a quarter of the length of the female malaria mosquito. The indicated difference is very clearly visible if you look at the figure. In addition, the mosquito has characteristic dark spots, which are unlikely to be found in other mosquitoes. Along with the differences listed above, another is the fact that the body of the mosquito, when it sits, is located at a strong angle above the surface.

Methods of infection

It is very interesting that, despite the external similarity of the female and male malaria mosquito, males do not pose a threat of disease transmission. The male Anopheles feeds only on plant sap. The female also does not always feed on blood. The need for blood arises only after fertilization has occurred, since animal protein is necessary for the formation of eggs. And nature made it so that during this period the insect is able to smell warm-blooded animals or humans at a distance of up to 3 km.

If the female manages to find a victim, then when she bites, she sucks out a volume of blood that exceeds her weight. This allows the eggs to develop in the female’s body, and then in the external environment. For two days after laying eggs, the female feeds only on plant juices, after which the process is repeated again.

If during her life a female malaria mosquito has not had contact with a person infected with malaria, then her bite does not pose any danger. However, it is not possible to know about this in advance. It is for this reason that every person must take all necessary safety measures and get vaccinated before traveling.

As is known, mosquito saliva contains malarial plasmodia, which are transmitted at the time of the bite. In this case, infection of a person who has been bitten almost always occurs. Once in the body, these substances begin to actively multiply, provoking the destruction of red blood cells, liver and spleen cells. Functionally active epithelial cells of organs are replaced over time connective tissue, after which the process of its growth occurs, the affected organs increase in size, beginning to put pressure on nearby tissues and vessels, and, ultimately, cease to function.

If the patient is not promptly provided health care and treatment is not carried out, the walls of the blood vessels will begin to collapse. This leads to symptoms of vasculitis, the development of numerous hemorrhages and anemia. In very severe cases, blockage of the capillaries of the brain can be observed, which contributes to the death of its parts.

According to experts, those at greatest risk of infection are:

• infants and children under 5 years of age;
• women during pregnancy;
• people with weakened immune systems, especially those with human immunodeficiency virus.

Symptoms of malaria infection

Modern medicine has in its arsenal effective ways combating diseases such as malaria. This may explain the fact that in countries with a well-established health care system fatal outcome Malaria infection is quite rare. The same cannot be said about hot countries located in the equatorial and subequatorial belts.

At the same time, an infected person experiences an allergic reaction, vomiting, and signs of anemia. In this case, blood appears in the patient’s urine. The person may experience severe convulsions. Quite often, patients consult a doctor with complaints of tingling skin. Sometimes it happens that their spleen is enlarged. Often such people experience excessive headaches and even cerebral ischemia. The doctor draws conclusions about malaria infection based on the results of the analysis of two types of blood smears.

It should be noted that in addition to malaria, the anafeles mosquito is a carrier of such serious diseases as lymphatic filariasis, tularemia, West Nile fever and Yellow fever.

Prevention measures

An insect like anafeles can infect a lot of people. For this reason, it is necessary to use means aimed at controlling and repelling this type of mosquito.

There are currently no chemicals available to prevent infection. At the same time, there are medications, helping to suppress and destroy an infection that has entered the body, but has not developed into a pathology.

In order to ensure personal protection, you should take special measures approximately within a week before the expected date of travel to a country where the risk of infection is high, as well as during the entire period of stay in the country and within a week after returning home. medicines aimed at preventing infection. Such drugs include Chloroquine, Fansidar, etc.

As experience shows, even specified measures do not always allow you to protect yourself from infection. But in this case, the symptoms of the disease will not be very pronounced, and complications will be avoided. Before taking such medications, you should consult your doctor. Also, after arriving home, it is necessary to undergo examination to exclude the possibility of infection.

All this knowledge and precautions will help a person reduce the likelihood of infection and protect him and those close to him from the virus if he decides to travel to a country where the most favorable conditions for infection.

Video - Mosquitoes

Who, heading from Rome to Naples by railway, was not lazy to look out the window, he, of course, saw that the train was crossing the area of ​​​​the Pontic swamps. Just a few decades ago, this was a sparsely populated region poisoned by fever, where penniless shepherds roamed. The Pontic marshes existed even before Roman rule was established here. Today it is a thriving area. The swamps were drained with the help of enormous drainages, fertile fields stretched out in place of the wastelands, cities and industrial enterprises grew.

But it was not the swamps themselves that prevented the use of this area for many centuries. Between the swamps there was land quite suitable for agricultural cultivation. However, those who settled here soon became victims of a severe fever. In the past, it was believed that it was caused by swamp fumes. In reality, the reason is different, and it should be said in more detail.

Malaria, or, as it is also called, intermittent fever, was widespread not only in the Pontic Marshes area, it was known in other areas of Southern and even Central Europe, just as in Russia. (This message is quite true in many areas Tsarist Russia; in the USSR, malaria was eliminated even in its most stubborn foci.) And in tropical countries even today it gives rise to terrible epidemics.

Fever is called intermittent because severe attacks of the disease usually alternate with days when the patient feels well. Many suffer seriously from fever, others die.

The cause of intermittent fever has been identified: it is caused by microscopic single-celled organisms of a very simple structure that settle in the human blood.

This is the only way to become infected with intermittent fever, and this disease is spread by mosquitoes of the genus Anopheles.

No one yet knows why, both in our rural areas and in the tropics, no other mosquitoes, even those very similar to Anopheles, are capable of transmitting the malaria pathogen.

We should pay tribute to the work of scientists. They revealed the connections existing in nature between different organisms and ensured the success of the fight against a dangerous disease. We now know that efforts must be focused on eradicating Anopheles. It is enough to destroy the carriers - the changing fever ends. There are many means to achieve this goal or get closer to it.

For example, they drained the Pontic swamps, and deprived mosquitoes of the opportunity to reproduce their species here. But it was possible not to touch the reservoirs, but to destroy the mosquito brood with the help of fish, or aquatic bugs, or dragonfly larvae released into the reservoirs - they all do an excellent job. Reproduction of voracious perch and small bleak also gives good results. In warm regions, special toothy carp from South America are used to combat mosquito larvae. In their homeland, they reproduce so quickly that they are called “millionfish.”

When reservoirs are watered with oil, it spreads over the surface in a thin film, disrupting gas exchange between water and air, and this deprives mosquito larvae and pupae of the opportunity to receive oxygen and breathe. But oil cannot be used everywhere: it pollutes water, and by stopping gas exchange with the atmosphere, it threatens the existence of all living things in the reservoir.

Currently, another product is used - a synthetic drug in the form of dust. Floating on the surface, it poisons mosquito fry, but for the rest of the inhabitants of the reservoir, living deeper, as well as for humans, the drug is harmless. Therefore, it can also be used when treating swimming pools.

Unfortunately, mosquito forms that are resistant to the drug are emerging.

The method of exterminating mosquitoes depends on available resources and local conditions. However, under all circumstances (in the garden or while swimming), it is better not to come across either mosquitoes or their fat relatives - horseflies and gadflies. You can protect yourself from them by lubricating your skin special composition, which repels insects for several hours. (Small midges, as well as biting midges, especially annoy people and harass domestic animals. Many species of all these winged bloodsuckers are called the expressive word “midges.” In places of mass distribution, midges create difficult, sometimes unbearable conditions: you can neither work at full strength nor rest peacefully Entomologists and doctors, working together, are vigorously searching for measures to combat these still unconquered pests.)

Literature: Karl Frisch. “Ten little uninvited guests”, Moscow, 1970

The malaria mosquito has spread almost throughout the world. It exists even in countries where the malaria it spreads is an officially eradicated disease. In Russia, a representative of this species of mosquito can also be found - it lives in the European part and in Western Siberia. And here climatic conditions Eastern Siberia They are not suitable for it, since the winter there is especially cold and protracted. This insect in itself does not pose a danger, and it can only give a person a dangerous disease after it becomes infected.

Malaria mosquito - a threat to human health

Description of the species

An Anopheles mosquito is only a threat to humans if it has previously bitten a victim infected with malaria. On its proboscis it carries plasmodia and infects its next source of saturation with them. And since, it is they who pose the danger.

By 2005, science had studied and described 7 subgenera of malaria mosquitoes, which include about 440 species. About 10 species of these insects are found in Russia, and they settle mainly in the territories of the European and Far Eastern parts.

Body structure

An adult insect has an elongated body, a thin proboscis located on a small head, and long legs. The body is quite fragile and its strength suffers under mechanical stress. Thin wings are covered with scales and, when folded, are located horizontally above the abdomen.

The structure of a malaria mosquito will be as follows:

• the head is round in shape, the proboscis is its natural continuation; compound eyes and antennae are located on the head; on the lower part of the forehead there is a clypeus; there are scales and hairs on the crown and back of the head, on both sides of the head in front of the eyes there are cheeks shaped like plates;
• the proboscis has a complex structure and consists of two upper and two lower jaws, an upper and lower lip and a subpharyngeal; there are palps on the lower jaws; the upper jaws are represented by a thin strip of chitin, the flat end of which forms a blade; on the front half of the outer edge of this blade there are small teeth, the number of which can range from 30 to 50;
• the antennae are sensory organs, they are located in front of the eyes and are attached to a wide base plate; the second segment, located at the base of the antennae, contains Johnson's organ, which is presumably the organ of hearing; each antenna has fine hairs, which are much more numerous in males than in females;
• the chest consists of three parts: prothorax, mesothorax and metathorax; the prothorax bears the head, the mesothorax - the legs, wings and spiracles, the metathorax - the posterior thoracic spiracle;
• the abdomen is divided into 10 segments, the last two of which are part of the reproductive apparatus; the first eight segments are connected by the pleura, which stretches and allows the abdomen to increase in size during the act of eating and when bearing eggs.

Stages of development

A female malaria mosquito can lay 50 to 200 eggs at a time. She places the clutch on the surface of the water and each egg is able to find its comfortable position. Over time, the eggs sink to the bottom of the reservoir, where pupae form.

The larva of the malaria mosquito is born in about 2-3 days. But if the climatic conditions are unfavorable and the air temperature drops below the permissible level, then the miracle of birth can happen only 15-20 days after the female lays eggs.

The best development of the malaria mosquito occurs in a clean reservoir, which has not yet been overgrown with duckweed. Acidic waters with poor flora and fauna are not suitable for larvae, since during the growth process they simply will have nothing to eat. Food acceptable to them is found in reservoirs with slightly alkaline and neutral waters.

On a note! Filamentous algae also grow there, in which the larvae can hide from fish and other predators for whom they are a tasty morsel!

The body cover of the Anopheles mosquito larvae is a waterproof cuticle, covered with spines and hairs. Thanks to the hairs, it can move and catch the slightest vibrations in the water.

Larvae of the first, second and early third instars have one pair of eyes covered with scales. As they grow, at the end of the third instar and in the fourth instar, a second pair of eyes is formed - these are the rudiments of the compound eyes of an adult. In addition to the eyes, the larva's head has antennae and a mouth organ.

On a note! If the basis of nutrition is plankton, then the antennae will be especially long, if the larva feeds from the surface of the film and scrapes food from the bottom - short!

At the end of each of the four instars, the larva sheds its skin. With the end of the fourth instar, the development of the larva stops and it turns into a pupa. This stage is the last phase of growth - the cephalothorax cracks and the pupa becomes an adult.

Common and malarial mosquito: differences

As can be seen from the body structure, the malaria mosquito looks almost the same as a regular one, but differences still exist:

• the legs of the malaria mosquito are much longer than those of a normal mosquito, especially the hind ones;
• the tentacles of a female Anopheles are almost equal in size to the proboscis, in ordinary ones the length of the tentacle is equal to ¼ of the proboscis;
• the wings of an ordinary mosquito have a uniform color, while the malarial mosquito has spots on them;
• when Anopheles sits, its body is located at an angle and the back part will be noticeably raised; the body of an ordinary mosquito in a sitting position will be almost parallel to the surface;
• The malaria mosquito, before landing on the body of the victim, seems to be dancing in the air, which is different from the usual one.

Nutrition Features

The main source of nutrition for the female malaria mosquito is blood. Moreover, the victim in this case can be humans, mammals and even some invertebrates. Females choose their prey according to several criteria:

• size;
• level of radiated heat;
• odor emitted.

They need blood before laying eggs.

Malaria mosquitoes and, as observations show, even females, but only under forced circumstances, feed on nothing more than pollen and plant nectar.

On a note! For male representatives, the extracted carbohydrates are quite enough for normal life activities, but for the female half, such a diet is not the most acceptable, since they lose the ability to lay eggs.

Symptoms and consequences of bites

• tingling at the site of the bite;
• joint pain;
• intense headaches;
• vomit;
• convulsions;
• chills;
• fever;
• enlarged spleen;
• anemia;
• blood impurities in the urine;
• cerebral ischemia.

The bite of a malaria mosquito is especially dangerous for women during pregnancy and children under 5 years of age. Having bitten the victim, the insect introduces plasmodium into its body, which after half an hour reaches the liver, where they develop. Over time, the liver increases in size and its cells gradually die.

The malaria mosquito is dangerous because it infects about 400 million people every year, and kills about 1.5 million. In the greatest possible way African residents suffer from this disease - their number is 86%. And the forecasts are disappointing, since it is believed that within 20 years the mortality rate of Africans from malaria will double.

When a malaria mosquito bites a pregnant woman, it can lead to premature birth, eclampsia and death.

Babies may experience:

• diarrhea;
• vomit;
• convulsions;
• abdominal pain;
• chills at the beginning of the illness;
• at the end of the development of the disease, sweating;
• spots and hemorrhage on the skin;
• rapid development of anemia.

Symptoms in older children are similar to those in adults. Malaria in children is a particularly dangerous case. Death in such situations is common, especially between the ages of 6 months and 5 years. In this case, the most striking symptom is paroxysm, which is absent in children with malaria.

Malaria mosquito

mosquito Anopheles maculipennis(s. claviger) and other species of this genus, which are carriers of malaria or swamp fever, which is known to be caused by the presence of special microorganisms in human blood (see Malaria and Hemosporidia). The genus Anopheles belongs to the family Culicidae (see Mosquitoes) and contains mosquitoes similar to ordinary mosquitoes from the genus Culex. Males have 15 antennae, females have 14 segments. The tentacles of females are almost equal in length to the proboscis (in the genus Culex they = 1/4 of the proboscis); in males, the last 2 segments are club-shaped and thickened (in ordinary mosquitoes, all 3 segments are of the same thickness). The 3rd longitudinal vein on the wings forms a small branch included in the main cell (Culex does not have this branch). The legs are long, almost 2 times longer than the entire body and significantly longer than those of Culex. The abdomen is without scales, but only with hairs (whereas in ordinary mosquitoes it is almost completely covered with scales). The position taken by M. mosquitoes during rest is very characteristic: their body is almost perpendicular to the surface on which the mosquito sits, whereas in ordinary mosquitoes the body is located almost parallel to this surface. Anoph. maculipennis has almost transparent wings with 4 spots formed by dark scales; the veins and rear edge of the wings are also covered with dark scales. The main body color is brownish-yellow; tentacles and antennae are dark brown; the chest is bluish-gray on top with dark lines; the abdomen is grayish-yellow, sometimes with a dark stripe in the middle; length (including the proboscis) 6-11 mm. An. bifurcatus is very similar to the previous species, but its wings are without spots. The genus Anopheles is distributed in all parts of the world and M. mosquitoes are found in large quantities where there are foci of malaria (for example, in Japan there is no malaria and from the genus Anopheles A. chinensis is found as a great rarity, which in China, where malaria is widespread, is found in abundance). In general, there are fewer mosquitoes in the north of M. than in the south. Anopheles can live in areas very high above sea level (eg in the Himalayas at an altitude of 13,000 feet). The most important, at least for Europe, is An. maculipennis (s. claviger), which is distributed throughout Europe from Lapland to the very south, and is also found in North America.

Then An. bifurcatus (forest M. mosquito) also has a significant distribution in Europe (it is not present in the far north). An. nigripes is considered a variety of the previous species. The lifestyle of M. mosquitoes is still far from sufficiently studied, since only Lately, since their connection with malaria became known, they paid attention to these mosquitoes. Fertilized Anopheles females, which do not accept blood in the fall, overwinter in a torpored state in basements, stables, barns, attics, etc. non-residential premises, also under loose tree bark, in hollows, in moss (males die before wintering). Departure from wintering grounds occurs when warm weather V Central Russia around mid-April. In general, in the spring and early summer there are still relatively few M. mosquitoes; the greatest number of them is observed in the middle and second half of summer. M. mosquitoes are active only from dusk to sunrise; During the day, they avoid open, well-lit and windy areas and stay in sheltered areas. They love to be in living spaces (in warm corners of the room, on ceilings, walls, under tables, sofas, etc.).

An. maculipennis (as opposed to common mosquitoes) almost never attacks humans and animals in the evening or at night under open air, but does it indoors. M. mosquitoes feed on plant juices and the blood of mammals (they rarely bite birds); they can take blood every 48 hours (during this time the blood is digested at 25.5°C; at 20.7°C, digestion lasts 60 hours). The lifespan of M. mosquitoes is not known exactly. They do not travel significant distances from their place of birth; in the vertical direction, mosquitoes can rise up to 15 meters and higher. When mosquitoes lay eggs has not been established exactly (for the summer generation, in all likelihood, 20 days after fledging). Eggs are laid in the water (from 70 to 350 pieces) nearby in small groups of 10-12 eggs, which for the most part are soon divided into smaller groups of 3-4 eggs or even completely separated. The eggs are oblong, pointed at both ends, flat on one side, convex on the other, first white, then gray.

2-3 days after laying, at a temperature of 20-28° C., the larvae hatch. The larvae are green, gray or almost black. The head is almost conical, in front with 2 highly branched hairs, with eyes and rather long antennae; the upper and lower jaws are highly developed.

Malaria mosquito larva: O- breathing holes, l- fan-shaped hairs (enlarged)

On the sides there are mostly feathery hairs; on the 3rd, 4th, 5th, 6th and 7th abdominal segments there is a pair of small star-shaped branched setae. The respiratory openings are located on a slight elevation on the dorsal side of the 8th abdominal segment (larvae of the genus Culex have a long respiratory tube); the length of the adult larva is 8 mm. The larvae usually stay near the surface of the water in a horizontal position and live for about 20 days. The food of the larvae consists mainly of small algae (diatoms, desmids, Spirogyra and other filamentous algae), and particles of tissue of marsh plants; grown larvae also feed on animal food: small larvae of other insects, crustaceans, etc. The pupa of M. mosquito is very similar to the pupa of ordinary mosquitoes, differing mainly in shorter and straighter respiratory tubes located on the chest, and wider and shorter fin plates at the posterior end of the abdomen; color light green or darker; the pupal state lasts 2-5 days.

The emergence of a mosquito from the pupa lasts 5-10 minutes. Number of generations of An. maculipennis per year has not been precisely established and is apparently different for different areas (in central Russia, apparently, 2 generations develop, English observers talk about 4 generations). M. mosquitoes develop mainly in stagnant, predominantly swamp water, often also found in the smallest bodies of water, such as. in barrels, tubs, etc. In addition, the larvae are found in quiet waters, near the shores and tolerate brackish water containing 1% salt. They choose places overgrown with various aquatic plants: pondweed, water lilies, etc., and especially with various filamentous algae (Spirogyra, Cladophora, Hydrodictyon, etc.), forming mud or water wool on the surface of the water; The larvae avoid places covered with duckweed. The enemies of M. mosquitoes are various small fish, mainly from the carp family, then water bugs (Notonecta), some water beetles and their larvae, and dragonfly larvae. Adult mosquitoes are chased into large quantities dragonflies. - Lifestyle An. bifurcatus differs quite significantly from An. maculipennis; it stays mainly in forests, flying into dwellings relatively less often; its larvae are often found in very shallow puddles and springs with cold water. Due to the enormous importance of malaria, the issue of combating M. mosquitoes is very important. By good means the destruction of larvae is kerosene or fuel oil (of course only in standing water); These liquids, when poured onto water, are known to form a thin film on the surface of the water, which deprives mosquito larvae of the opportunity to obtain air. In this case, there is no need to poison all standing water in a given area, since Anopheles larvae are not found in all water bodies. All in. America is poured 2 lots of kerosene per 15 square meters. feet of water surface (special devices are used for this purpose). After 2 days the larvae die; At the same time, female mosquitoes that arrive to lay eggs also die. Then, to exterminate the larvae, it is very important to populate the water basins with fish; Small fish from the carp family (carp, crucian carp, roach, ide), then ruff, minnow and others are especially willing to eat mosquito larvae; At the same time, it must be borne in mind that it is first necessary to collect mud or water wool floating on the surface of the water, since the larvae in it are largely protected from fish. Finally, drainage of swamps, drainage and sewerage are also very important, although, of course, not possible everywhere. The fight against mosquitoes as carriers of malaria was carried out with the above-mentioned means in the United States. America, in Havana, on the Suez Canal and elsewhere. places; the results were very satisfactory and the number of malaria patients decreased significantly in these areas. Further, to protect people from being bitten by mosquitoes, metal or muslin nets are used, inserted into the windows of houses (the surface of the mesh holes is 4 sq. mm). Since An. maculipennis, as we saw above, attacks people almost exclusively in houses and therefore can be called, in Grassi's expression, a house insect, then the advice usually given to go home before sunset and not leave your home until sunrise has no special significance. Since malaria patients are sources of mosquito infection, it is necessary to isolate patients from mosquitoes. - Wed. Grassi, "Die Malaria" (Jena, 1901); Kirschbaumer, "Malaria, ihr Wesen, ihre Entstehung und ihre Verhütung" (Vienna and Lpc., 1901); Theobald, "A Monograph of the Culicidae" (L., 1901-1903); Nuttal and Shipley, "Studies in Relation to Malaria," in Journal of Hygiene (Volumes I and II); Porchinsky, “The Malarial Mosquito,” in Proceedings of the Bureau of Entomology (vol. 5, 1904).

M.R.-K.

encyclopedic Dictionary F. Brockhaus and I.A. Efron. - St. Petersburg: Brockhaus-Efron. 1890-1907 .

Synonyms:

Mosquitoes (family Culicidae)

Distributed everywhere. The three most common mosquito genera are Anopheles, Culex and Aedes.

Morphological features: adult mosquitoes have a slender, elongated body of small size. The head contains large compound eyes, long antennae and mouthparts. Females have piercing-sucking mouthparts. In males, the oral apparatus is sucking, its piercing parts are reduced. They feed on the nectar of flowers. On the sides oral apparatus segmented antennae lie. A pair of transparent wings is attached to the mesothorax. The abdomen is formed by 10 segments, the last two are modified into genital appendages (Fig. 65).

Biology of mosquitoes. A new generation of mosquitoes hatching from pupae undergoes a period of physiological maturation that lasts about four days. At this time, they live near water bodies and feed on nectar. Then, at dusk, the males form a swarm, the females fly into it, mating occurs, after which the females must drink blood for the development of eggs. They actively search for prey at a distance of up to 3 km from a body of water, flying indoors. Having drunk blood, females hide for several days in darkened rooms or thickets of bushes. During the digestion of blood, eggs mature (gonotrophic cycle) . Mosquitoes can only go through one gonotrophic cycle per summer. (monocyclic) or several (polycyclic). Female mosquitoes in summer time live about 1 month, males - 10-15 days.

After the eggs mature, the female flies to the pond and lays eggs (350450) on its surface. Larvae emerge from the eggs. The duration of larval development depends on the water temperature. The minimum development period is 15 days at the optimal temperature (250 C). Development begins at a water temperature of at least 100 C. The larvae feed on bacteria and plant debris, molt several times and turn into pupae, from which a new generation of adults emerges. In polycyclic species, during the warm season there are from 2 to 5-7 generations (depending on natural conditions).

In most species of mosquitoes (Anopheles and Culex species), fertilized females overwinter, and in species of the genus Aedes, eggs. When autumn comes

During cold weather, males fertilize females and die. Females feed on blood to form a fat body, on which they survive during the winter. Egg development is inhibited. With the onset of warm weather spring days females fly out of their shelters and again feed on blood to mature their eggs. From the laid eggs, a new generation of males and females consistently develops.

Eggs. Anopheles mosquitoes lay eggs in stagnant or weakly flowing, unshaded bodies of water with clean water. The eggs have a belt with air chambers and float one at a time (Fig. 66).

Rice. 66. Morphology of mosquitoes. A – eggs of mosquitoes of the genus Culex, B – larva of Culex, C – pupa of Culex, D – head of a male Culex, E – head of a female of Culex, E – eggs of mosquitoes of the genus Anopheles, G – larva of Anopheles, H – pupa of Anopheles,

head of a male Anopheles, head of a female Anopheles.

Aedes mosquitoes lay eggs one at a time in temporary reservoirs: puddles, cans, hollows, etc. The eggs have an elongated oval shape without air chambers.

Culex eggs are wedge-shaped without air chambers and are laid on the surface of the water glued together in a boat shape.

Larvae. The larvae of Culex and Aedes mosquitoes have a respiratory siphon on the penultimate abdominal segment in the form of a narrow tube, at the end of which stigmata (tracheal openings) are located. The larvae are located at an angle to the surface of the water and breathe atmospheric air.

The larvae of Anopheles mosquitoes do not have a siphon and are located parallel to the surface of the water. A pair of stigmata, through which they breathe atmospheric air, is located on the penultimate abdominal segment.

Aedes mosquitoes are characterized by non-simultaneous hatching of larvae from eggs of the same clutch; it lasts for weeks and even months (adaptation to living in periodically drying up water bodies).

Pupae. The pupae are comma shaped. On the dorsal side of the cephalothorax there is a pair of respiratory siphons. With their help, the pupae are “suspended” to the surface film of water. In Culex and Aedes mosquitoes, the siphons are cylindrical, while in Anopheles they are funnel-shaped (conical).

Adult forms (imago). Adults differ in their position, the pattern of their wings, and the structure of their head appendages.

U mosquitoes For Culex and Aedes, the abdomen is located parallel to the surface on which they sit; in Anopheles mosquitoes, the rear end of the abdomen is raised.

Some species of malaria mosquitoes have dark spots on the wings; non-malaria mosquitoes do not have them.

The heads of males of all mosquitoes have heavily pubescent mandibular antennae, while in females they are weakly pubescent.

U In Anopheles females, the mandibular palps are equal in length to the proboscis,

A in females Culex and Aedes they are 1/3-1/4 length of proboscis.

U In Anopheles males, the mandibular palps are equal in length to the proboscis and have club-shaped thickenings at the end; in non-malarial mosquitoes they are usually longer than the proboscis and have no thickenings.

Anopheles mosquitoes are specific carriers and definitive hosts of malaria pathogens, specific vectors and intermediate hosts wucherer and brugi

Aedes mosquitoes are specific carriers of pathogens of Japanese encephalitis, yellow fever, Dengue fever, lymphocytic choriomeningitis, anthrax, wuchereriosis, brugiosis, tularemia.

Culex mosquitoes are specific carriers of the pathogens of Japanese encephalitis, tularemia and wuchereriosis.

Mosquito control measures come down to the following areas:

1. Direct protection against mosquito attacks (wearing closed clothing, using repellents, covering the windows of residential premises, animal prevention - creating biological barriers ( livestock farms) between mosquito breeding sites and residential buildings, etc.).

2. Fight against winged mosquitoes – spraying insecticides in wintering and overnighting areas of mosquitoes (basements, attics, barnyards).

3. Fight against larvae:

a) drainage of small reservoirs of no economic importance; b) use of pesticides; c) shading of reservoirs by trees;

d) reclamation work to drain swamps, deepen reservoirs, straighten river beds;

e) spraying mineral oils over the surface of reservoirs, clogging stigmas; f) breeding gambusia fish (biological control method).