What does a malaria mosquito look like? Anopheles. Mosquitoes carry malaria

Mosquitoes, or real mosquitoes, or blood-sucking mosquitoes(lat. Culicidae) - a family of dipterous insects belonging to the group of long-whiskered insects (Nematocera). There are more than 3,000 species of mosquitoes in the world, belonging to 38 genera. Russia is home to representatives of 100 species belonging to the genera of true mosquitoes (Culex), biters (Aedes), Culiseta, malaria mosquitoes (Anopheles), Toxorhinchites, Uranotaenia, Orthopodomyia, Coquillettidia.
Mosquitoes are insects with thin body(4-14 mm long), long legs and narrow transparent wings. Body color is yellow, brown or gray. The abdomen is elongated, consisting of 10 segments. The chest is wider than the abdomen. The paws end in a pair of claws. The wings are covered with scales, the accumulations of which sometimes form spots. The antennae are long and consist of 15 segments. The mouthparts are piercing-sucking type. In females the proboscis is long and consists of piercing bristles, in males it is without them.
The mosquito insect has 4 phases of development: egg, larva, pupa, imago. Moreover, all phases, except adults, live in reservoirs. Mosquito larvae and pupae living in water breathe atmospheric air through the breathing tubes, exposing them to the surface. Mosquito larvae - filter feeders or scrapers - feed on aquatic microorganisms. The feeding of adults is often dual: females of most mosquito species drink the blood of vertebrates: mammals, birds, reptiles and amphibians; at the same time, males of all species of mosquitoes, without exception, feed on the nectar of flowering plants.
REPRODUCTION.During the mating period, female mosquitoes attract the attention of males with a characteristic subtle sound, reminiscent of a squeak, which is created with the help of their wings. Mosquitoes detect sound vibrations with their sensitive antennae. Females squeak a little thinner than males, young ones - not as much as old ones. And male mosquitoes hear this and make a choice in favor of adult females. Mosquitoes form a swarm, where males and females mate. A female mosquito lays 30-150, and even 280 eggs (in malaria mosquitoes) every 2-3 days. The egg develops into an adult mosquito within a week. To reproduce eggs, mosquitoes require blood, so the egg laying cycle is directly dependent on blood consumption. Eggs are laid in stagnant or low-flowing reservoirs on the surface of the water ( genera Anopheles and Culex), on wet soil at the edge of water in reservoirs that dry up in summer and are flooded in spring, or stick to floating objects washed by water (in Aedes).
MEDICAL IMPORTANCE. Mosquitoes are an integral component of natural communities. The number of groups of animals for which they are food amounts to dozens. In addition, mosquitoes, like other insects, whose larvae actively feed in aquatic environment, are one of the main reasons for the inexhaustibility of soils
Mosquitoes are carriers of dangerous diseases: malaria, yellow fever, dengue and some encephalitis. Of these diseases, malaria alone causes about two million deaths each year. In addition, their bites can cause itching and allergic reaction.

Phylum: Arthropoda Subtype: Tracheata Class: Insecta Order: Diptera Family: Culicidae Genus: Culex	Phylum: Arthropoda Subtype: Tracheata Class: Insecta Order: Diptera Family: Culicidae Genus: Anopheles
Imago. Female: mandibular palpi several times shorter than the proboscis. Male: mandibular palps longer than the proboscis, without club-shaped thickenings at the ends. When landing, the body is bent, the abdomen is inclined towards the substrate or parallel to it.	Female: mandibular palps equal in length to proboscis. Male: mandibular palps equal in length to the proboscis, with club-shaped thickenings at the ends. When landing, the body is kept elevated and at an angle to the surface.
Eggs. They do not have a belt or cameras. They are laid on the surface of the water in boat-shaped piles.	They are laid scattered on the surface of the water. Each is bordered by a concave belt and equipped with swimming chambers.
Larvae. They have a respiratory siphon on the penultimate segment. In water they are located at an angle, attached by a siphon to the surface of the water.	There is no breathing siphon. They have only one pair of respiratory openings on the penultimate segment and therefore are located horizontally in the water.
Pupae. The pupa is shaped like a comma. The breathing tube has a cylindrical shape.	The pupa is shaped like a comma. It differs in the structure of the breathing tube; it has a conical shape.

Widely distributed on all continents except Antarctica. Absent in desert areas and in the far north (the northernmost point of the range is the south of Karelia). There are about 430 species in the world fauna, 10 species in Russia and neighboring countries. In Russia they live in the European part and Western Siberia. Don't live in Eastern Siberia where winters are too harsh for them. A mosquito becomes infected with Plasmodium falciparum from a human patient or carrier. The malarial plasmodium undergoes a cycle of sexual reproduction in the mosquito's body. An infected mosquito becomes a source of infection for humans 4-10 days after infection and remains so for 16-45 days. Mosquitoes also serve as carriers of other types of plasmodia that cause malaria in animals.

Malaria: pathogenic significance, diagnosis, prevention.

In malaria caused by P. malariae, the intervals between attacks are 72 hours. Asymptomatic carriage is common.

With tropical malaria, at the onset of the disease, the intervals between attacks may be different, but then they are repeated every 24 hours. With this type of malaria, there is a high risk of death due to complications from the central nervous system or kidneys. Tropical malaria is especially dangerous for representatives of the Caucasian race.

A person can become infected with malaria not only through the bite of an infected mosquito. Infection is also possible through blood transfusion (transfusion) of infected donor blood. Most often, this method of infection occurs with four-day malaria, since in this case there are few schizonts in erythrocytes, they may not be detected when examining the blood of donors.

Diagnostics

It is possible only during the period of erythrocyte schizogony, when the pathogen can be detected in the blood. Plasmodium, which has recently penetrated into an erythrocyte, has the appearance of a ring. The cytoplasm in it, in the form of a rim, surrounds a large vacuole. The core is shifted to the edge.

It occupies almost the entire red blood cell. Next, fragmentation of the schizont occurs: in the deformed erythrocyte, many merozoites are found, each of which contains a nucleus. In addition to asexual forms, gametocytes can also be found in erythrocytes. They are larger and do not have pseudopods or vacuoles.

Prevention

Identification and treatment of all patients with malaria (elimination of the source of mosquito infestation) and destruction of mosquitoes (elimination of vectors) using special insecticides and reclamation work (draining swamps).

When traveling to areas unfavorable for malaria, you should take antimalarial drugs prophylactically and protect yourself from mosquito bites (use mosquito nets, apply repellents to the skin).

The body of the pupa is shaped like a comma and consists of two sections. The expanded anterior section is ovoid in shape and corresponds to the head and chest of the future mosquito. On the underside of the anterior part of the body there is an eye in the form of a dark spot, enclosed in a transparent case. The developing organs of an adult mosquito are visible through the transparent cover: the rudiments oral apparatus, limbs, wings.

On the dorsal surface of the anterior part of the body there are two respiratory siphons, which look like funnel-shaped tubes. A narrow segmented abdomen is tucked under the front part of the body.

Head of a female non-malarial mosquito Culex pipiens

The preparation shows the head of a female non-malarial mosquito, with its dorsal side up. From leading edge a long thin proboscis extends from the head. The proboscis is a modified lower lip that has a groove-like appearance. The piercing parts of the oral apparatus are located in it as if in a case and are not visible through a microscope. The proboscis has two small blades at the free end, used for inserting piercing mouthparts into the skin of the host. On both sides of the proboscis, three-segmented mandibular palps are visible, four times shorter in length than the proboscis. Along their entire length they are covered with small hairs. The mandibular palps are appendages of the lower jaws and perform a tactile function. Outside the mandibular palps there are multi-segmented, slightly pubescent antennae - the organs of smell. At the junctions of the segments, short hairs are arranged whorled. The entire front part of the head is occupied by a pair of large faceted (mosaic) eyes. Outwardly, they resemble a honeycomb. Each facet (ocelli) of compound eyes is clearly visible.

Head of a male non-malarial mosquito Culex pipiens

The preparation shows the head of a male non-malarial mosquito, with its dorsal side up. A long thin proboscis extends from the anterior edge of the head. The proboscis is a modified lower lip that has a groove-like appearance. The piercing parts of the oral apparatus are located in it as if in a case and are not visible through a microscope. In the male, the upper and lower jaws - the piercing parts of the oral apparatus - are underdeveloped. Therefore, the sucking mouthparts of the male cannot pierce the skin; it provides nutrition to the males with nectar and plant juice. On both sides of the proboscis, mandibular palps are visible, longer than the proboscis; all segments have the same thickness. Along their entire length they are covered with small hairs. The mandibular palps are appendages of the lower jaws and perform a tactile function. Outside the mandibular palps there are multi-segmented, highly pubescent antennae - the organs of smell. At the junctions of the segments, long hairs are arranged in a whorled pattern. The entire front part of the head is occupied by a pair of large faceted (mosaic) eyes. Outwardly, they resemble a honeycomb. Each facet (ocelli) of compound eyes is clearly visible.

Egg of the non-malarial mosquito Culex pipiens

The egg has an elongated shape. The lower end of the egg is wide and blunt, and the upper end is narrower. At the lower end of the egg there is a cap protruding outward. Some preparations show the side of a “boat” formed by several dozen eggs of a non-malarial mosquito.

Larva of the non-malarial mosquito Culex pipiens

The specimen clearly shows the elongated body of the larva, 2-3 mm in size, consisting of three sections: a massive head, a large chest and a segmented abdomen. The head is clearly demarcated from the chest. On the sides of the head there are compound eyes, in front there are two fan-shaped fans and rod-shaped antennae. Fans are oral appendages consisting of thin and long hairs, which, moving rhythmically, force water and food particles contained in it into the larvae’s mouth.

The thoracic region is greatly distended. The segmented abdomen consists of 9 segments. In the middle of the abdomen, in the form of a dark spot, the intestines are visible through the integument of the body. Tubular tracheas stretch on both sides of the intestine. A long breathing tube, the respiratory siphon, extends from the penultimate abdominal segment. Stigmas (breathing holes) are located at the end of the siphon.

The last segment contains two clearly visible tufts of steering setae, which are used by the larva to increase the paddle surface when the larvae move. From the last segment extend 4 elongated transparent appendages - anal gills, which play an important role in the processes of osmoregulation.

The entire body of the larva is covered with numerous hairs: the chest and the first three segments of the abdomen are covered with simple setae and there are no stellate setae, unlike the larva of the analaria mosquito.

Pupa of the non-malarial mosquito Culex pipiens

The body of a mosquito pupa is shaped like a comma and consists of two sections. The expanded anterior section is ovoid in shape and corresponds to the head and chest of the future mosquito. On the underside of the anterior part of the body there is an eye in the form of a dark spot, enclosed in a transparent case. The developing organs of an adult mosquito are visible through the transparent cover of the pupa: the rudiments of the oral apparatus, limbs, and wings.

On the dorsal surface of the anterior part of the body there are two respiratory siphons, which look like cylindrical tubes. A narrow segmented abdomen is tucked under the front part of the body.

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 poor 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 and 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 To combat mosquito larvae, they use special toothed carp from South America. 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 and biting midges especially annoy people and torment 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

Mosquitoes of this genus are found everywhere except Antarctica. However, only in endemic areas is transmission of malaria by mosquitoes possible. different types.The persistent population of mosquitoes and the continuing likelihood of mosquito infection with malaria plasmodia pose a risk of repeated outbreaks of malaria in humans.

Mosquito development.

Evolution occurs in four stages: egg, larva, pupa, and adult. The first three stages take place in water and the adult insect lives 5-14 days, depending on the species and ambient temperature.

Adult females lay 50-200 eggs. The eggs are laid in water, are not resistant to drying out and open within 2-3 days, when unfavorable conditions can exist until the next stage for up to 2-3 weeks.

The larvae of mosquitoes of the genus Anopheles are not adapted to breathing in water and therefore are located near the surface, breathing through spiracles located in the 8th abdominal segment.

The larvae feed on algae, bacteria and other microorganisms and swim in jerky movements. The larvae also develop in 4 stages, the change of stages is accompanied by a change in the outer chitinous shell - molting. For the development of a mosquito, it is necessary to have reservoirs with fresh, clean water- swamps, mangrove swamps, rice fields, grassy ditches, banks of streams and rivers, temporary rain ponds, possibly in pools and even in the axils of leaves filled with water.

The mosquito pupa is shaped like a comma and is also located at the surface of the water for breathing. The duration of evolution from egg to adult mosquito depends on the species and habitat conditions, on average 10-14 days in tropical conditions.

Adult mosquitoes

Like all mosquitoes, adult anophelines are distinguished by a head, thorax and abdomen. The head contains eyes, sensory antennae, and a proboscis for feeding. On the chest there are 3 pairs of legs and a pair of wings. The stomach contains the digestive and reproductive organs. The abdomen can increase significantly in size as it fills with blood and the eggs mature. Blood is digested over a long period of time. Mosquitoes of the genus Anopheles can be distinguished by the palps located next to the proboscis, by the presence of a distinct pattern on the wings, as well as by their typical situation before the bite. After turning from a pupa, adults are inactive for several days; males gather in flocks to attract females for mating. Males live for about a week and feed on plant nectar. Females can also feed on nectar, but for the normal development of their offspring they need to receive blood. After the bite, the females rest for several days, during which time the blood is digested and the eggs mature. Duration depends on external conditions, usually takes 2-3 days in tropical conditions. As soon as the eggs are fully mature, the female lays them in a pond and again looks for an opportunity to feed on blood until she dies. The lifespan of a female reaches 1 month.

Factors associated with malaria transmission and malaria control

For the transmission and development of plasmodia in the body of a mosquito, a certain lifespan of the intermediate host, the mosquito, is required. On average, it takes 10 to 21 days for Plasmodium to develop into a form that is infectious to humans. Consequently, shortening the life of a mosquito will lead to a decrease in human morbidity. This is facilitated by the use of insecticides

The feeding factor of mosquitoes during the crepuscular (active at dusk or dawn) or nocturnal (active at night) period, place of feeding and rest after feeding - outdoors (exophilic and exophagic) or indoors (endophilic and endophagic). Limiting the ability of a mosquito to bite at a time and place convenient for it through the use of mosquito nets and the construction of premises with limited access will also lead to limiting the transmission of malaria from mosquito to person.

A factor in reducing the number of places where the mosquito’s aquatic phase develops is draining swamps and moving away from dwellings.

Insecticide resistance

Resistance to chemicals may occur quite quickly in connection with birth large quantity generations throughout the year. There are more than 125 species of mosquitoes that are resistant to one or more insecticides.

Modern developments.

Some Anopheles species are able to independently eliminate plasmodia that have entered the body. These species are being carefully studied with the goal of introducing a similar mechanism to the entire mosquito population.

The malaria mosquito spreads malaria, the most common disease in the world. globe, Japanese encephalitis and brungiosis. Malaria is common in more than 100 countries in Africa, South America and Asia. Malaria affects millions of people every year. So in 2014, 214 million cases of the disease were registered. 480 thousand patients died from malaria.

The maximum number of cases and deaths (up to 90%) occurs in the countries of the African continent located south of the Sahara, where the most severe form of the disease is recorded - tropical malaria. Cases of malaria have been reported in India, Sri Lanka, Vietnam, Brazil, Solomon Islands and Colombia. About 1 million children die from malaria every year. In a number of countries where malaria is not common, more than 30 thousand cases of “imported” malaria are recorded, 30% of which are fatal.

Rice. 1. Prevalence of malaria.

Family Culicidae(mosquitoes) belong to the suborder Nematocera(long mustache). The most common mosquitoes of the genus Culex, Anopheles(subfamily Anophelinae), Aedes, Culiceta, Mansonia(subfamily Culicinae). Plasmodium malaria is transmitted by female Anopheles mosquitoes. Of the 400 species of Anopheles mosquitoes, only 30 are carriers of this infection.

Malaria mosquitoes transmit 4 types of malarial plasmodia to humans:

Plasmodium vivax is the causative agent of tertian malaria.
Plasmodium malariae is the causative agent of four-day malaria.
Plasmodium falciparum is the causative agent of tropical malaria.
Plasmodium ovale is the causative agent of tertian malaria.

Rice. 2. Bite of a malarial mosquito (photo on the left) and a non-malarial one (photo on the right).

Rice. 3. At the moment of the bite, the back of the malaria mosquito’s abdomen rises and is at an angle to the skin.

Rice. 4. Anopheles mosquito bite. In a calm state, the wings of females are folded horizontally along the abdomen.

What does a malaria mosquito look like: the structure of the insect

The mosquito's eyes are scalloped and consist of many ommatidia.

Rice. 5. The mosquito's eyes are scalloped and consist of many ommatidia.

Oral apparatus

The oral apparatus of mosquitoes is a piercing and cutting instrument represented by a proboscis, which consists of the upper and lower lips, the hypopharynx (subpharynx) and two pairs of upper (mandibles) and lower (maxilla) jaws.

The lower lip is a tube. It serves as a support for stabbing stilettos. Blood passes through it as it is absorbed. Blood is consumed only by females, for whom it serves as a nutrient for the maturation of eggs. Males feed only on plant juices, so the piercing parts of their oral apparatus are atrophied.

The organs of touch and taste in mosquitoes are 5-segmented palps extending from the base of the lower jaws. Their length and shape serve distinctive features malarial and non-malarial mosquitoes: in malarial mosquitoes, the palps and the length of the proboscis are equal in length and have club-shaped thickenings at the ends; in non-malarial mosquitoes, the palps are longer than the proboscis and do not have club-shaped thickenings at the ends.

Rice. 6. The structure of malaria mosquitoes.

Antennas

Antennas or antennae located on the front surface of the head perform the function of recognizing smells and touch. In males, the antennae are covered with thick and fluffy hairs, in females they are short and sparse.

Legs, wings and halteres

The malaria mosquito has a pair of wings, three pairs of thin legs and halteres, which are attached to the mosquito's chest.

Mosquito wings

The wings of malaria mosquitoes are elongated-oval with a large number transverse and longitudinal veins, covered with microtrichia (small hairs). Different types of mosquitoes have their own pattern. Malaria mosquitoes have 4 brown spots on their wings. Non-malarial mosquitoes have alternating dark and light spots. At the mosquito in a calm state, the wings fold horizontally along the abdomen.

Abdomen

The abdomen of mosquitoes consists of ten segments, the ninth and tenth of which form part of the external genitalia. The body of mosquitoes is elongated, the head is small, and the legs are long. When landing on mosquitoes of the genus the back of the abdomen is raised; in non-malarial mosquitoes, the abdomen is parallel to the skin.

Rice. 7. Bite of female malarial (photo on the left) and non-malarial (photo on the right) mosquitoes.

Rice. 8. The structure of a mosquito genus Culex(picture on the left) and Anopheles (photo on the right).

Biological characteristics of mosquitoes

The life of a female consists of repeating cycles: searching for a host (prey), blood sucking, development of sexual forms, flight to a reservoir and laying eggs. Such cycles are repeated 8 to 10 times. In this case, up to 20% of females die.

Breeding sites

Before the eggs mature, female malaria mosquitoes hide in well-lit and warm water bodies rich in vegetation. Female mosquitoes of the genus Culex they hide near housing - in holes, ditches, barrels, sheds, attics, burrows, artificial reservoirs.

Locations of the attack

Female mosquitoes need human or animal blood to mature their eggs. Females Anopheles maculipennis most often attacked in homes Anopheleshyrcamus- under open air, females of the genus Cules- near the home, in houses, near populated areas.

Seasonality

The period of activity of female malaria mosquitoes is from spring to autumn. The maximum number of bites is recorded in July and August. Female non-malarial mosquitoes are more likely to bite humans in August and September. In the tropics, the period of mosquito activity reaches 8 - 10 months, in the equatorial countries of Africa - all year round.

Laying eggs

Female malarial and non-malarial mosquitoes lay eggs singly on water; non-malarial mosquitoes also lay eggs near water - on the bottom of a dry reservoir or its banks.

Rice. 9. The photo shows a Culex mosquito bite.

Mosquito development cycle

In mosquitoes of the genus Culex the eggs are glued together and form a “boat” that floats freely in the water. They have an oblong shape and a widened front part with a saucer-shaped rim that allows them to stay on the surface of the water. A characteristic concavity is formed on the surface of the “boat”.

Eggs of a female mosquito they are located singly, bordered by a concave belt, and have 2 air chambers-floats that allow them to stay on the surface of the water.

Eggs female genus Aedes deposits on the bottom of drying up reservoirs, located singly, oval in shape, with a micropyle (small entrance) at one end. After 2 - 14 days, larvae emerge from the eggs.

Rice. 10. Mosquito eggs.

Rice. 11. Eggs and larvae of mosquitoes of the genus Culex.

Larvae

The larvae feed intensively and grow. Before pupation, they increase more than 500 times in volume and more than 8 times in length.

In mosquito larvae Culex And Aedes there is a special respiratory tube-siphon, which extends from the penultimate (ninth) segment of the abdomen. Using a siphon tube, the larvae are held at the surface of the water, positioned perpendicular to the surface of the reservoir. Air enters the siphon through the spiracles. This design helps mosquitoes survive in heavily polluted ponds, ditches, puddles, water vessels and tree hollows.
In mosquito larvae there is no siphon tube. A pair of stigmas extending from the penultimate abdominal segment helps them stay parallel to the surface of the water. The larvae survive only in clean water bodies.

The larvae feed through a flow of liquid with microscopic nutrients, which is created by fans located at the head end. The particle size is limited, which is taken into account when using dust-like pesticides.

The larvae go through 4 stages in their development, separated by molting. After the last molt, the larvae turn into pupae.

Rice. 12. Anopheles mosquito larva (photo on the left) and Culex (photo on the right).

Rice. 13. Anopheles mosquito larva at the surface of a reservoir (picture above) and Culex (picture below).

Rice. 14. The photo shows Anopheles mosquito larvae.

Pupae

During the pupal stage, the insect develops eyes, wings, a proboscis, and legs. Mosquito pupae are mobile.

Pupae Culex And Aedes have a cylindrical breathing siphon. Pupae have a breathing siphon in the shape of a “mail horn”. This stage ends with the emergence of the winged mosquito, the adult, from the chitinous shell. The development phase in water until the winged form emerges lasts 14 - 30 days. The warmer the water, the faster the winged forms of insects emerge.

Rice. 15. Anopheles pupa (photo on the left) and Culex pupa (photo on the right).

Rice. 16. Anopheles pupa (picture on the left) and Culex pupa (picture on the right).

Winged Forms

Malaria mosquitoes live near human habitation - in non-residential buildings, near water bodies (breeding sites). During the day, females and males hide in dark corners. At dusk they fly out in search of food, which they find by smell. Insects feed on plant juices, milk, and consume sugar solution and cesspool liquid.
After mating, the female must pump blood, without which the eggs do not develop, for which they attack humans, domestic and wild animals. Females sense clusters of animals at a distance of up to 3 km.
Females suck blood for 0.5 to 2 minutes and suck out more blood than their body weight - up to 3 mg. If this happens in spring and summer, then eggs are formed in the female. If in the fall, a fat body is formed from the pumped blood, but the eggs do not develop.
After this, they hide in dark places, most often in human housing and premises where livestock are kept. After 2 - 14 days, larvae emerge from the eggs.
Insects overwinter in basements, cellars, storerooms, animal rooms - wherever there are no drafts or light. In winter, mosquitoes are in a state of torpor. The female becomes able to lay eggs already in the middle of winter, but only after sucking blood. Mosquitoes leave their shelters en masse only in the warm season, biting at dawn and dusk.
IN warm days females migrate to a pond where they lay eggs. The first laying of eggs is carried out by overwintered females.
After laying eggs, females fly off in search of food. One female can repeat the egg-laying cycle several times.

Plasmodium malaria is transmitted by mosquitoes of the genus Anopheles. During wintering, the sporozoites in the female’s body die. For it to become infected, a new infection from a sick person will be required.

Rice. 17. The winged form of mosquitoes (imago) Anopheles (picture above) and Culex (picture below).

Ecology of adult mosquitoes

There are a number of features in mosquitoes of the genus , knowledge of which allows us to assess their role in the transmission of infection:

Female malaria mosquitoes feed not only on plant nectar, but also suck the blood of mammals, which allows them to survive for a long time in winter period and ripen the eggs.
Female mosquitoes of the genus and other species of mosquitoes with a dual feeding pattern are carriers of a number of diseases. The malaria mosquito carries 4 types of malarial plasmodia, the causative agent of Japanese encephalitis and one type of Brugia. Mosquito genus Culex are carriers of Japanese encephalitis and 2 types of Japanese encephalitis filariae.
In female mosquitoes of the genus Culex And Aedes The presence of desosomes in the intestinal epithelial cells ensures their adhesion. In female mosquitoes of the genus intestinal epithelial cells are poor in desosomes.
Cutting apparatus of the proboscis has teeth along the edge. Other species of mosquitoes do not have them. The hypopharynges, which serve to shed saliva, have finger-like projections at the ends, which increases the number of sporozoites that enter the blood of a person or animal. This is also facilitated by the presence of a gap in the salivary canal. The dissected salivary ducts allow the female mosquito to drink blood 2 to 3 times longer than regular mosquitoes.
Mosquito genus pierce the skin at an angle. The narrow mouth parts and the curvature of the piercing parts facilitate the sucking of blood from the most superficial capillaries, where the patient with malaria accumulates maximum quantity young sporozoites.