Everything about malaria mosquitoes - habitat, how to distinguish them and facts. Malaria mosquito Video - Mosquitoes

Anopheles is widely known as a species of malaria mosquito, as it is considered the primary carrier of the disease. It is also a transmitter of heartworm in dogs.

Description

The Anopheles mosquito prefers to feed on mammals, including humans.
The dark brown to black colored body of the adult Anopheles mosquito has 3 sections which are the head, chest and belly.

When resting, the insect's stomach region points upward, rather than parallel to the surface, as in most mosquitoes. Anopheles females reproduce several times during their lives. short life, producing eggs after finding blood. Although they live only from a few weeks to a month, they produce thousands of eggs during this time.

A female mosquito lays up to 200 eggs on the surface of the water. Each of the single eggs remains on the water using floats. They take anywhere from two days to three weeks to hatch, depending on the temperature environment.

Mosquito larvae are called wigglers because they move in a unique way. They lie parallel to the surface of the water to feed on fungi, bacteria and other tiny organisms. The larvae go through four stages before becoming pupae.
The pupae are known as tumblers. The pupae come to the surface of the water to breathe using tiny "tubes" and do not eat for 1-2 days until they become adults.

Breeding habit

Anopheles mosquitoes lay eggs in the most different places. Breeding sites malaria mosquitoes is it fresh or salty water. Above-ground pools, small streams, irrigated lands, freshwater swamps, forested pools, and any other place with clean, slow-moving water are considered prime breeding grounds for malaria mosquitoes.

Females, especially fertilized ones, survive the winter by hibernating in caves, meaning the breeding cycle can continue all year round. Eggs are able to withstand cold temperatures; however, freezing usually kills them.

To learn more Why do you dream about mosquitoes?

Geography

Where do malaria mosquitoes live? Anopheles live almost anywhere in the world, with the exception of Antarctica. They are found in places where malaria has been eradicated, so there is always the possibility that they could reinfect the area.

All it takes is blood from a person or mammal infected with malaria for them to be able to pass it on to another person or mammal. The person who was initially infected may have just traveled to an area where malaria is present, or an unsuspecting visitor to an endemic region brought the disease.

Because global tourism is common today, the possibility of reinfection of a previously clean area always exists. In addition, regions that have never had an outbreak may become an endemic area for the first time. Where do malaria mosquitoes live? Anywhere. Effective mosquito control systems can provide protection against these pests and the diseases they transmit.

• There are about 430 species of Anopheles mosquitoes, but only 30 to 40 species of mosquitoes carry malaria.
• Many species of Anopheles mosquitoes have become resistant to insecticides over years of pesticide use.
• The Anopheles mosquito is most active at two times: just before dawn and just after dark. At this time of day, controlling mosquitoes outdoors is important to ensure protection from being bitten.
• The Anopheles mosquito causes an outbreak of "airport malaria" when accidentally imported through luggage or an airplane.
• Sir Ronald Ross, who proved the transmission of malaria by the Anopheles mosquito, was not only a scientist; also a mathematician, writer, poet, editor, composer, artist.

The Anopheles mosquito is still found in many areas where malaria has been eradicated. Although the parasite has been eradicated, it is still present and malaria may return after one bite from a malaria mosquito.

For mosquitoes (order Diptera, suborder Long-whiskered) external features are thin body, long legs and a small head with a proboscis-type mouthparts. Mosquitoes are ubiquitous, especially in warm, humid climates. Mosquitoes are carriers of more than 50 diseases. Mosquitoes - representatives of the genera Culex and ncdcs (non-malarial) are carriers of pathogens of Japanese encephalitis, yellow fever, anthrax, representatives of the genus Nnopheles (malarial mosquitoes) - carriers of malarial plasmodium. Non-malarial and malarial mosquitoes differ from each other at all stages of the life cycle.

All mosquitoes lay their eggs in water or moist soil near bodies of water. Eggs of mosquitoes of the genus nnopheles are located on the surface of the water one at a time, each egg has two air floats. Their larvae are located under water parallel to its surface; on the penultimate segment they have two breathing holes. The pupae are comma-shaped, develop under the surface of the water and breathe oxygen through respiratory horns in the form of wide funnels. Adult mosquitoes of the genus nnopheles, sitting on objects, raise their body up and keep their head down, forming sharp corner with the surface. On both sides of their proboscis there are mandibular palps equal in length. Mosquitoes of the genera Culex and Aedes lay eggs in groups in the water. The larvae in the water lie at an angle to its surface and have a long respiratory siphon on the penultimate segment. The pupae are also comma-shaped, but their breathing horns are shaped like thin cylindrical tubes. The mandibular palps of adult mosquitoes barely reach a third of the length of the proboscis. When sitting on objects, mosquitoes keep their bodies parallel to their surface.

The malaria mosquito is the definitive host, and humans are intermediate host the protozoan falciparum plasmodium (type of sporozoan). The development cycle of malarial plasmodium consists of three parts:

1) schizogony – asexual reproduction by multiple division;

2) gametogony – sexual reproduction;

3) sporogony - the formation of forms specific to sporozoites (sporozoites).

Piercing the skin healthy person, the invasive mosquito injects saliva into its bloodstream containing sporozoites, which invade the liver cells (gametocytes). There they turn first into trophozoites, then into schizonts.

Many people have been afraid of malarial mosquitoes since childhood, knowing that they are carriers of the causative agent of an extremely dangerous disease - malaria. These concerns are not without merit. Find out in detail how the Anopheles mosquito differs from other harmless species of such insects - this information will help prevent serious risks to your health.

What does a malaria mosquito look like?

Insects classified as belonging to this species are often called anopheles by biologists (short for Latin name Anopheles maculipennis). These dipterans appearance They are not much different from ordinary mosquitoes. Anopheles has a small body (6-10 mm), a small head and long legs. These insects have dark spots on their transparent scaly wings, which is not the case with ordinary mosquitoes. Their jaw system consists of a lower lip (with the help of saw-like jaws on it, Anopheles cuts through the skin) and a proboscis (the mosquito pushes it into the slot and sucks blood).

Where does it live?

These insects, which are a source of deadly infection for humans, are distributed almost throughout the world. Geography of the regions where it lives malaria mosquito, includes all areas where there is no harsh winters(during prolonged cold weather, the development cycle of anopheles is interrupted). In the world, these carriers of infection are very widespread in areas with hot climates.

Thus, on islands close to the equator, in the countries of Africa, Central and South America, and South-East Asia About a million people die every year due to malaria through the bites of Anopheles mosquitoes. In Russia, although these insects are found in the European part of the country and in Western Siberia, but here they are not so dangerous. In this area, the ambient temperature is not conducive to their rapid reproduction, and there are no carriers of malaria in this area.

How is it different from normal

Insect carriers of the infectious agent have some structural features of their bodies. A very noticeable difference between the malaria mosquito and the ordinary one is that it has long hind legs. This characteristic external sign You can clearly see the insect in the photo. Due to this structural feature, the rear part of the body of a sessile anopheles is always at a large angle to the surface, and the body of an ordinary mosquito is always located parallel to the surface on which it is located.

Another important difference observed in the structure of females. The jointed tentacles located on the head of the female Anopheles are almost equal in length to the proboscis. In ordinary mosquitoes, such tentacles are noticeably shorter - no longer than ¼ of the proboscis. These two types of insects can also be distinguished by dark spots on the wings, which are present in malaria carriers and are absent in ordinary individuals. Another striking feature of anopheles is that they do not immediately sit on the victim’s skin, but before attacking they seem to dance in the air.

Types of malaria mosquitoes

In practice, this type of mosquito includes all dipterans from the genus Anopheles, of which there are more than 460 species in the world today. It is important to know that only about 100 species of these insects can actually transmit malaria. IN different regions pose an epidemiological danger different types Anopheles. Interesting fact: many people believe that the centipede mosquito, an insect distinguished by its large sizes. The facts suggest that such dipterans are harmless, because their food is nectar, or they may not eat at all.

Why is it dangerous?

Only female Anopheles species pose a threat to human health. Male mosquitoes live only a few days and feed only on plant juices. Females of these insects can live up to two months. They eat too plant foods, but during the breeding season they need animal blood as a source of protein to form their eggs. Having received such food, the female processes it for about two days and again looks for a new victim of attack.

What happens if you are bitten by a malaria mosquito?

You need to know that the bites of such insects do not in all cases pose a real danger. Infection will only occur if a female malaria mosquito has previously bitten a person with malaria. Only after contact with blood, in which plasmodia already live, does the insect become infectious. The ability to infect malaria will also not be passed on to the offspring of this female.

Scheme of transmission of the malaria pathogen to humans

What does a bite look like?

Based on the appearance of the skin, it is difficult to determine which insect bit a person - an ordinary mosquito or an anopheles. The bite of a malaria mosquito also itches, and the skin may appear red and slightly swollen. Often, the patient learns that an infection with malarial plasmodium has occurred after the end of the incubation period. He begins to show characteristic severe symptoms of the disease: chills, fever, headaches, rapid pulse and even convulsions.

How to protect yourself from the malaria mosquito

What precautions should be taken to prevent the risk of contracting a serious illness? Due to the fact that Anopheles lays eggs in water bodies and here in the summer new insects emerge from the larvae, high risk the bite occurs, for example, while relaxing near the water. To prevent infection when staying outdoors, it is recommended to use different mosquito repellents. Thus, repellents will repel dipterans well, and mosquito nets will keep out not only large insects (such as the long-legged mosquito or anopheles mosquito), but also other midges from entering the tent.

Video

Attention! The information presented in the article is for informational purposes only. The materials in the article do not encourage self-treatment. Only a qualified doctor can make a diagnosis and make recommendations for treatment based on the individual characteristics of a particular patient.

Aghajanyan Khoren

What role do mosquitoes play in transmitting malaria diseases? What was the situation with malaria during the creation of the resort city of Sochi? Are there any on site Black Sea coast Caucasus malarial mosquitoes now? What measures need to be taken to prevent the spread of mosquitoes along the Black Sea coast? The author sought answers to these questions while conducting his research.

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Agadzhanyan Khoren Armenovich

"Mosquitoes of the genera Culex and Anopheles

and their role in the spread of malaria"

Novoselova Irina Anatolyevna,

additional education teacher

Sochi Ecological and Biological Center named after. S.Yu.Sokolova

Russia, Krasnodar region, Sochi,

Municipal educational institution secondary school No. 86, Sochi

Ecological and Biological Center named after. S.Yu. Sokolova, Sochi,

circle "Ecological Bulletin"

1. Introduction. Page 2

2. Main part. Study of mosquitoes, larvae and pupae of the genus Culex. Page 4

2.1. Comparison of mosquitoes of the genus Culex and malaria mosquitoes of the genus

Anopheles (according to my own observations and literary sources). Page 6

3. Conclusion. Preventive measures to prevent

the spread of mosquitoes along the Black Sea coast. Page 10

4. List of references. Page 11

5. Applications. Page 12

1. Introduction.

IN Lately messages news agencies filled with information about outbreaks of malaria infection in different regions of the world. Ukraine, Greece, Madeira Island... The appearance of malaria indicates that dangerous infectious diseases can appear after a long period of calm, spread quite quickly and cover large areas.

What role do mosquitoes play in transmitting malaria diseases? What was the situation with malaria during the creation of the resort city of Sochi? Are there malaria mosquitoes on the territory of the Black Sea coast of the Caucasus now? What measures need to be taken to prevent the spread of mosquitoes along the Black Sea coast? I sought answers to these questions while conducting my research.

Goal of the work: compare mosquitoes of the genera Culex and Anopheles and find out their role in the spread of malaria.

Tasks:

1.Study the history of malaria.

2. Study the history of the fight against the spread of malaria on the Black Sea coast of the Caucasus.

3. Conduct observations of the life and development of mosquitoes of the genus Culex, study the biology of Anopheles mosquitoes from literary sources.

4.Draw conclusions about the role of mosquitoes in the spread of malaria and about preventive measures to prevent the spread of mosquitoes along the Black Sea coast.

In my work on studying mosquitoes, I used information from the Internet, as well as books from the series “Everything that lives from an egg” “ Life cycle insects" (R. Spilsbury), "Under the Looking Glass, or Mysterious world reservoir" (V.B. Verbitsky), "Old Sochi" (K.A. Gordon), "Guide to laboratory classes in biology" (V. Korolev), "Whims of nature" (I. Akimushkin), "For young nature lovers "(N. Plavilshchikov), "Arthropods. Insects" (V.N. Alekseev).

The name comes from Italian phrase mala aria - “bad air”. It is believed that people have been suffering from malaria for 50,000 years. Malaria is believed to be native to West and Central Africa.

From the history of our city, I learned that until the mid-twentieth century, malaria, which was facilitated by the warm and humid climate, was a real disaster for settlers. The mortality rate was high. The highlanders did not suffer from mosquito bites, since they settled higher in the mountains, and the city area was very swampy, which was the reason for the high incidence of malaria.

Residents settlements They didn’t even think that the disease was caused by a mosquito. Many people took seriously the idea that malaria was caused by raw fruit!

The first Sochi doctor A.L. Gordon made a lot of efforts to fight malaria. He ordered imported quinine for delivery to the city - the only means of control at that time, treated the sick, promoted ways to avoid infection: settle on highlands, take quinine prophylactically, pour a small layer of kerosene into stagnant lakes and swamps to destroy mosquito larvae and pupae, close window frames with gauze nets.

In 1921, an antimalarial station was created in Sochi. Since 1923, Dr. S.Yu. became the head of the Sochi antimalarial station. Sokolov. He set himself a very difficult task: not only to organize treatment, but also to eliminate the very cause of the disease: wetlands were drained, pollination was carried out with “Paris greens” (a composition based on copper sulfate) and the surface of standing reservoirs was covered with a thin film of kerosene, gambusia was brought in, destroys malaria mosquito larvae in large quantities in water bodies. Eucalyptus trees were planted throughout the city, which perfectly drained the soil. In 1956 malaria was eliminated in Sochi.

2. Main part. Study of mosquitoes, pupae and larvae of the genus Culex.

I conducted my mosquito research as follows. First, I studied the literature on mosquito biology. Then he examined the caught mosquitoes using a magnifying glass, and the larvae and pupae of mosquitoes using a BIOR school microscope.

The mosquito (Culex) belongs to the order Diptera and is a representative of the large family of mosquitoes (Cullcidae). A small insect (6-7 mm) with a large chest, a long narrow abdomen and one pair of narrow wings. The male differs from the female in having more developed antennae. They attack people and animals and feed on their blood exclusively by females, whose proboscis has piercing bristles. Males feed on plant juices.

Female mosquitoes spend the winter hiding in hollows, basements and other secluded places. In the spring they fly out and look for food. Only females attack people and animals (small and large animals, naked bird chicks). Having sucked on blood, mosquitoes go to secluded places to digest the blood, this is the only way eggs can mature in their bodies.

I caught mosquito larvae and pupae from a bath of rainwater. Number of larvae – 48 pcs. Pupae – 5 pcs. Observations of the larvae allowed me to become more familiar with their lifestyle.

Female mosquitoes lay eggs in bodies of water and end their lives. Eggs can withstand drying and freezing. Therefore, mosquito eggs can overwinter in the pond. Larvae emerge from the eggs. The larvae feed at the bottom of the reservoir. Their food is microscopic animals: bacteria, ciliates, larvae of other mosquitoes, algae, sludge particles.

The larvae develop very quickly: the warmer the water, the faster the larvae develop.Observing the movement of the larvae and studying them under a microscope, I saw thatTheir movement in the water is aided by swimming hairs, which sit in tufts on the body segments. The largest tuft is on the last caudal segment. If you do not allow the larva to emerge, it will suffocate. Larvae breathe atmospheric air, the supply of which in the body requires constant replenishment. When they rise to the surface, they put their tail breathing tube out of the water and draw air into the trachea. The breathing tube is a long, obliquely extending process that is clearly visible through a microscope.

The larva of the common mosquito is easy to distinguish from the larvae of other invertebrates - it seems to hang in the water at an angle (40°-60°) upside down. It is held by the surface tension of the liquid, forming an elastic film, which the larva pierces with its respiratory process and to which it is suspended from below.The larvae move upward, curving like a worm, and fall down vertically, as they are too heavy. The larva develops and molts three times as it develops, and then turns into a pupa, which is completely different from the larva.Having compared the caught larvae with those shown in the figure, I determined thatall the larvae I caught correspond to Figure 1, i.e. belong to mosquitoes of the genus Culex.

Among the specimens I caught there were 5 pupae. They were also interesting to watch.Pupae that look like commas swim near the surface of the water: they have a large cephalothorax (because the head and chest are covered common shell) and a narrow curved abdomen. They move, jumping into the depths. But the larva does not stay at depth for long: it is very light and floats up by itself. In water, the pupa takes a different position than the larva. Suspended to the surface, it exposes not the rear, but the front end of its body from the water. On the dorsal side of the front part of the body it has a pair of respiratory tubes, which are visible to the naked eye and resemble small horns, giving the animal a very distinctive appearance. The pupa raises these horns out of the water when breathing.

Pupae, like larvae, dive into the water, but move differently: hitting the water with their abdomen, which ends in fins, they somersault over their heads; After staying at the bottom for some time, the pupae float up again, holding their horns up and passively rising to the surface, since their body is lighter than water, having an extensive air chamber inside. The pupa does not accept any food. The older the pupa, the darker it is. Before hatching, it turns from light brown to almost black. A ripe pupa bursts on the surface of the water.

The mosquito leaves the shell, the edges of which it clings to until its wings straighten and dry, and it flies into the air.

The usual duration of development of an ordinary mosquito (at a temperature of 15-20°) is about a month, and in the pupal stage the insect lives on average about 2-5 days.In samples of mosquito larvae and pupae that I collected in stagnant water, mosquitoes emerged from the pupae on the third day.

2.1. Comparison of mosquitoes of the genus Culex and malaria mosquitoes of the genus Anopheles (according to our own observations and literary sources).

Having observed the behavior of mosquitoes, their larvae and pupae, and having read the literature about mosquitoes of the genus Anopheles, I came to the conclusion that they have many distinctive features and it is quite difficult to confuse a common mosquito and a malaria mosquito. Comparative characteristics I present these mosquitoes in the form of a table.

Photos (digital microscope BIOR) were taken by the author, photos of mosquitoes, larvae, pupae in nature - Novoselova Alexandra.

3. Conclusion. Preventive measures to prevent the spread of mosquitoes along the Black Sea coast.

Due to the extreme danger of malaria, close attention to this disease is required. Therefore, preventing the spread of malaria throughout Russia and in Sochi is very important.

I divided the methods that are used to prevent the spread of the disease or for protection into 2 categories: global and household (“home”).

Global include: 1) Prevention: destruction of mosquito breeding sites - stagnant bodies of water. Specialists from Stavropol Research The Anti-Plague Institute is launching a pilot project to create a map of water bodies, including the territory of Sochi.

2) Reservoirs should be populated with the unique fish Gambusia, which is capable of eating mosquito larvae and pupae in unlimited quantities.

3) Identification of sick people at quarantine points of border territories is the task of the border and customs service.

4) At the level of research institutes, this is active work on the creation of an anti-mosquito vaccine or the creation of a genetic modification of a mosquito resistant to malaria.

At home, you can use mosquito nets, repellents, medicines to prevent bites (Menovazin, Zvezdochka balm), essential oils of some plants (mint, rosemary, fir and juniper oil, etc.), scented candles and sticks.

I would like to continue working on this topic. My future plans for studying mosquitoes are to study the action essential oils on mosquito larvae and pupae.

4. List of references.

1. Akimushkin I. Freaks of nature. M.Mysl.1981
2. Alekseev V.N. Arthropods. Insects. M. Bustard.2004
3. Verbitsky V.B. Under the Looking Glass, or the Mysterious World of the Pond. M. Bustard. 2002.
4. Gordon K.A. Old Sochi of the late 19th - early 20th centuries (memoirs of an eyewitness). Sochi. 2004.
5. Korolev V.A. Guide to laboratory classes in biology. Kyiv. Vishcha school. 1986
6. Plavilshchikov N.N. For young nature lovers. M. Children's literature. 1975
7. Raikov B.E., Rimsky-Korsakov M.N. Zoological excursions. M.1956.
8. Spilsbury R. All living things come from eggs. Life cycle of insects. Mnemosyne.2009.
9. gambusia.org

Mosquitoes of this genus are found everywhere except Antarctica. However, only in endemic areas is transmission of malaria by mosquitoes of different species possible. The persistent population of mosquitoes and the continuing likelihood of mosquito infection with Plasmodium malaria 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 living conditions, on average it is 10-14 days per 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 position 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, feeding 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

Resistant 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.