Where is the malaria mosquito found and why is its bite dangerous? Anopheles, or malaria mosquito (Anopheles maculipennis) A member of the genus Anopheles is caused by biology.

Accent placement: ANO`FELES

ANOPHELES (Aporneez; Greek anōphelēs - harmful, dangerous) - a genus of blood-sucking mosquitoes of the family Culicidae (blood-sucking), suborder Nematocera (long-whiskered), order Diptera (two-winged); main vectors of malaria pathogens. The genus includes more than 300 species and subspecies, grouped into 6 subgenera.

In the USSR, there are 7 species of the subgenus Anopheles - A. maculipennis (5 of its subspecies are registered: A. m. messeae, A. m. sacharovi, A. m. maculipennis, A. m. atroparvus, A. m. melanoon), A. hyrcanus, A. claviger, A. plumbeus, A. algeriensis, A. marteri, A. lindesayi and 2 species of the subgenus Myzomyia - A. superpictus, A. pulcherrimus.

A. common in countries with tropical, subtropical and temperate climate. The northern border of their habitat within the USSR runs approx. 65° N. w.

The development cycle of A. consists of eggs, larvae, pupa (Fig. 1-3), living in water, and adult forms - adults, populating land. The female A. lays 200-260 cigar-shaped eggs on the surface of the reservoir, equipped with special air chambers, so that they do not submerge in the water. The upper surface of the egg has dark spots or stripes or painted plain. Larvae of A. (size 0.5-1.3 mm) spend most of their lives at the surface of the water and feed from its surface film. Larvae breathe atmospheric air with the help of tracheas that open with two stigmas on the dorsal side of the VIII abdominal segment. Larvae different types A. differ in the structure and location of clypeal, frontal and antennal hairs on the head.

In their development, the larvae go through 4 stages, turning into a pupa after the 4th molt. The pupa is inactive, does not feed and breathes using respiratory tubes that have a conical shape. The breeding grounds for A. are permanent and long-term temporary natural and artificial reservoirs.

The A. imago is characterized by a long, slightly convex chest with an entire scutum and long thin legs covered with small, tightly fitting scales; mandibular palps of A. are equal in length to the proboscis (Fig. 4).

A. copulation occurs during swarming. After fertilization, females develop a need for blood sucking, since the development of a portion of eggs is possible only in parallel with the digestion of a portion of blood - gonotrophic harmony. The exceptions are A. claviger, A. hyrcanus and A. plumbeus, in which the first oviposition can occur without prior blood sucking. During her life, the female makes several ovipositions, which makes it possible for mosquitoes to participate in the transmission of pathogens, since each oviposition is preceded by bloodsucking, and each new bloodsucking is associated with the possibility of infection of a mosquito or a person from an infected mosquito. A. females feed on the blood of mammals and humans. Males feed only on plant juices. Females of A. maculipennis, A. superpictus and A. pulcherrimus can make long flights in search of prey. Human settlements are the center of attraction for them. The area from which mosquitoes flock to the village is called the gravitational zone (its radius on the plain is up to 3 km). Villages of the gravitational zone, which partially coincide, are called conjugate. There is an active exchange of mosquitoes between them, which should be taken into account when analyzing the epidemiological situation. When determining the degree of contact of mosquitoes with humans, the anthropophilicity index is used (the percentage of mosquitoes feeding on humans out of the total number of mosquitoes feeding).

The digestion of blood in A. and the development of eggs occurs in shelters (day shelters) of various types.

A. hyrcanus, A. claviger and other species choose refuges only in natural conditions- exophiles. Other species (endophiles) are distributed between refuges in nature and the village, depending on the degree of favorableness of their microclimate. The more mosquitoes are left to digest blood and develop eggs in human structures, the more endophilic the population. After the eggs mature, the females scatter in search of a body of water to lay them. Over the next 24 hours, the female drinks blood again. Thus, her life consists of a series of successive gonotrophic cycles(cm.).

By the number of extensions on the stalk of the oviduct, the female determines the number of ovipositions she has made and her physiological age (Fig. 5). The older the female, the greater her epidemiological danger. Epidemiologically dangerous are females whose bodies have completed the sporogony cycle (see. Malaria) and sporozoites appeared in salivary glands. In practice, only potentially dangerous females (POF) are identified, in whose body the sporogony cycle could be completed, provided that the infection occurred during the first blood sucking. To calculate the age of the POS, it is necessary to know the duration of sporogony under given conditions and the physiological age that the female will reach by this moment. With an increase in the number of PICs in a population, the epidemiological significance of the population increases.

The number of generations per year depends on weather conditions. Near northern border range of A. maculipennis produces 2 generations per year, in the Caucasus and Central Asia - 6-8.

Medical significance of Anopheles. Some A. species are specific carriers and definitive hosts of pathogens malaria(see) (Plasmodiuni vivax, P. falciparum, P. rnalariae, P. ovale). In the body of mosquitoes, plasmodium undergoes a certain development cycle - sporogony, as a result of which it is impossible to become infected with malaria without bypassing the carrier. Human infection occurs at the time of blood sucking (specific inoculation), sporozoites enter the wound with saliva. It has been proven that 65 species and subspecies of A. can be carriers of plasmodium, the area of ​​which determines the nosoarea of ​​malaria. However, the main vectors in the world fauna are considered to be 25-30 species living in various geographical areas. So, for example, in the European part of the USSR and Siberia the main carrier is A. maculipennis, in Transcaucasia - A. maculipennis and A. superpictus, in Central Asia - A. maculipennis, A. superpictus and A. pulcherrimus; V Southeast Asia- A. minimus, A. culicifacies, A. sundaicus, etc.; V Central Africa- A. gambiae, A. funestus; in South America - A. darlingi, A. albimanus, A. aquasalis; in Central America - A. albimanus, 4. pseudopunctipennis, A. aquasalis, etc. Secondary carriers in the fauna of the USSR: A.hyrcanus, A. claviger, in a number of areas - A. plumbeus.

The role of A. in the transmission of arboviruses is small. Thus, in Czechoslovakia the Chalovo virus was isolated from A. maculipennis. African species A. - carriers of pathogens of o'nyong-nyong fever.

To properly organize the fight against the vector, you need to know them species composition, epidemiological significance and biology of the main vectors.

The fight against A. comes down to the destruction of adult individuals and their larvae. To destroy the larvae, drugs from the group of chlorinated hydrocarbons (DDT, HCH), organophosphorus compounds (methyl nitrophos, bytex, thiodiphenylamine), etc. are used. DDT is used in the form of 10% dust, consumption rate 1 kg/ha in sparsely overgrown reservoirs and 2 kg/ha in heavily overgrown areas; HCH - in the form of 12% dust, the consumption rate is the same. Technical thiodiphenylamine powder is consumed at 0.6 kg/ha in sparsely overgrown areas and at 1 kg/ha in heavily overgrown reservoirs. You can also use Parisian greens (intestinal poison), spraying it over the surface film of water. Processing times are set in accordance with the data phenological observations. Treatment begins when larvae of the II-III stage of development appear in reservoirs.

Promising biological methods struggle: in the south - settlement of reservoirs viviparous fish Gambusia, in northern regions- fry of grass carp.

Processing settlements carried out when malaria patients are detected in them. In the case of single diseases, the patient’s homestead and neighboring areas are treated (microfocal treatment). If there are several patients, a complete treatment of the locality is carried out.

The use of dusts indoors is prohibited. DDT is used in the form of a suspension or emulsion (1-2 G technical product for 1 m 2 squares).

The residual effect of the drug lasts throughout the season.

When planning villages, it is necessary to be guided by the principle of animal prevention: place livestock on the edge of the village, thus diverting most of the flying mosquitoes. For personal protection repellents are used, which are applied to the skin and clothing: DEET, repellin-alpha, dimethyl phthalate, benzimine.

See also Blood-sucking mosquitoes, vectors.

Bibliography.: Beklemishev V. N. Ecology of the malaria mosquito (Anopheles maculipennis Mg.), M., 1944; Gutsevich A. V., Monchadsky A. S.. And Shtakelberg A. A. Mosquitoes, family Gulicidae, Fauna of the USSR, Diptera insects, vol. 3. century. 4, L., 1970; Detinova T. S.. Methods for establishing the age composition of dipteran insects having medical significance, trans. from English, M., 1962.

S. N. Zarechnaya.

Sources:

1. Big medical encyclopedia. Volume 1/Editor-in-Chief Academician B.V. Petrovsky; publishing house "Soviet Encyclopedia"; Moscow, 1974.- 576 p.

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Species belonging to this family are distributed from the tundra zone to desert oases.

They are small in size. The head contains large compound eyes, antennae and mouthparts. Only females with piercing-sucking mouthparts are blood-sucking. It consists of a groove-shaped lower lip, upper lip in the form of a plate closing the groove from above, a pair of lower and a pair of upper jaws in the form of bristles (piercing apparatus) and a tongue (hypopharynx), inside which the canal passes salivary gland. All piercing parts lie in a case formed by the upper and lower lips. The appendages of the lower jaws are the mandibular palps. In males the apparatus is sucking, the piercing parts are reduced. Mosquitoes feed on the nectar of flowers. On the sides oral apparatus The antennae lie, in males they are covered with long hairs, in females they are covered with short ones. The development of mosquitoes occurs with complete metamorphosis. Depending on the type of mosquito, breeding sites can be natural or artificial reservoirs. Mating occurs in the air (“mosquito dancing”). After fertilization, the female needs blood feeding to develop her eggs. The process of digesting food and maturing eggs is called gonotrophic cycle. With gonotrophic harmony, one portion of blood is enough for the maturation and laying of eggs.

Life expectancy of a female summer time up to 3 months, and males up to 10-15 days. In autumn, gonotrophic harmony is disrupted, and two or three meals of blood are required for egg maturation. Blood is used not only for the development of eggs, but also for the formation of a fat body, thanks to which fertilized females survive the winter.

Each mosquito species has certain morphophysiological and environmental features. Differences exist at all stages of development.

Mosquito eggs The genus Anofeles develops in bodies of water with stagnant and low-flow water. They float on the surface of the water alone. They have air chambers. Culex mosquito eggs have an elongated shape and are laid in large groups (300-400 pieces). Sticking together, they form a “boat” floating on the surface of the water. Mosquitoes of the genus Aedes lay eggs one at a time on the bottom of drying up reservoirs.

Mosquito larvae The genus Anopheles lives in clean water bodies. They have a worm-like shape. They are located parallel to the surface of the water. They are held in this position with the help of palm-shaped bristles located on the segments. On the dorsal side of the penultimate abdominal segment they have a pair of stigmata. Mosquito larvae genus Culex can live in polluted waters. On the penultimate segment of the abdomen they have a respiratory siphon in the form of a narrow tube with a stigma at the free end. Therefore, the larvae of common mosquitoes are located at an angle to the surface of the water. The last segment contains leaf-shaped anal gills and tufts of setae. The larvae of Aedes mosquitoes live in temporarily drying up reservoirs, puddles, hollow trees, vessels with water, and can live in polluted reservoirs. The larvae feed intensively and grow, molting four times

and develop into the pupal stage.

Mosquito pupae. The body is shaped like a comma. Consists of a wide cephalothorax and a narrow segmented abdomen. The pupae do not feed. During the pupal stage, restructuring occurs internal organs, and organs characteristic of the imaginal stage appear. Main hallmark The pupae of the malaria mosquito are shaped like a respiratory siphon: the tube has a conical (funnel-shaped) shape. Pupae of mosquitoes of the genus Culex are characterized by the presence on the upper side of the front part of the body of two respiratory siphons in the form of cylindrical tubes.

Mature individuals (imagoes) are formed from pupae. Differences in winged forms are manifested in landing, the structure of the head appendages and the color of the wings. When landing, the abdomen of the malaria mosquito is raised and is at an angle to the surface of the water, and common mosquito- parallel to the surface. In Anopheles females, the mandibular palps are equal in length to the proboscis; in Culex females, they are shorter than the proboscis and are approximately 1/3-1/4 of its length. Anopheles males have club-shaped thickenings at the ends of the mandibular palps; Culex males have mandibular palps longer than the proboscis, do not have club-shaped thickenings.

The pubescence of the antennae is more pronounced in males and is a manifestation of sexual dimorphism.

Due to changes in environmental and socio-economic conditions in a number of southern countries In the CIS (Azerbaijan and Tajikistan), local outbreaks and epidemics of three-day malaria occur. The massive importation of malaria into Russia threatens the spread of malaria. Malariological situation in the territory Russian Federation has changed since 1996. The largest importation of malaria into major cities Russia was noted in 2000.

Currently, epidemiological surveillance of malaria in Russia is aimed at maintaining well-being in malariogenic areas, since there are many factors that increase the risk of the spread of malaria.

Factors for the spread of malaria:

a. Natural and climatic conditions: floods and floods; climate warming; the presence of numerous breeding sites for malaria mosquitoes;

b. Features of certain types of malaria vectors and pathogens: susceptibility of mosquitoes to imported malaria pathogens; epidemiological effectiveness of local vectors; mosquito resistance to certain insecticides;

c. Development economic activity population: rice cultivation; fish farming; country house construction;

d. Population migrations: flights of ships and planes to the tropics; tourism to endemic countries; arrival of seasonal workers from endemic countries; nomadism of Tajik gypsies; business trips of businessmen to endemic countries;

e. Economic difficulties: reduction in funding for anti-malaria enterprises; deficit medicines for treatment and chemical prophylaxis; shortage of medical personnel carrying out epidemiological surveillance;

f. Social and cultural level of the population: low level of knowledge of the population about malaria; lack of means of protection against mosquito bites among the population; non-compliance with medication regimen; lack of insecticidal treatments of residential premises.

Mosquito control measures and malaria prevention. For personal protection, repellents and mechanical means are used: gauze curtains, nets, etc. The main measures of public prevention are the destruction of larval forms and breeding sites of mosquitoes. The fight against larvae consists of the following measures: 1) destruction of small abandoned water tanks; 2) spraying pesticides in water bodies serving as breeding sites; 3) oiling of reservoirs, preventing the supply of oxygen; 4) a change in the type of vegetation in a reservoir or a change in the degree of overgrowth; 5) drainage of the area, reclamation work; 6) biological control measures (breeding mosquito fish); 7) the use of zooprevention - the location of livestock farms between mosquito breeding sites and residential buildings. Insecticides are used to combat winged forms.

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 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

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.

Order Diptera (Diptera)

Diptera are an order of insects with complete metamorphosis. A distinctive feature of the order, which distinguishes it well from other groups of insects, is the presence of only one front pair of wings. Their posterior pair is transformed into club-shaped organs of balance - halteres - and does not have a locomotor function. The science of dipterous insects is dipterology.

About 120,000 species of Diptera have been described. The most characteristic representatives of dipterans are mosquitoes, midges, horse flies, and true flies.

Many blood-sucking dipterans are carriers of infectious diseases (malaria, yellow fever, etc.). However, at the same time, they are of great importance for agriculture, since they are pollinators of various plants, including cultivated ones. The body shape of adult dipterans is very diverse. Everyone knows slender, long-legged mosquitoes and stocky, short-bodied flies, but only experts will classify the microscopic wingless “bee louse” or the female of one of the humpback species found in anthills, which looks more like a very small cockroach, into this order.

Morphology of the imaginal stages of malarial and non-malarial mosquitoes.

Slender elongated body. On the head there are large faceted eyes and long antennae. Females have a piercing-sucking mouthparts, males have a sucking mouthparts, the piercing parts are reduced (they feed on nectar). On the sides of the mouthparts are segmented antennae. A pair of transparent wings is attached to the mesothorax. Abdomen - 10 segments, the last 2 modified into genital appendages. At the end of the abdomen, the female has genital appendages in the form of a pair of protrusions; the male has a complex, pincer-like copulatory organ. The shape of the genital organs is the most reliable way to determine the sex and type of mosquito. The ties are thin and long. The body of mosquitoes is covered with scales or hairs (the shape and location are different).

Adults differ in their position, the pattern of their wings, and the structure of their head appendages.

In Culex and Aedes, the abdomen is parallel to the surface on which they sit; in Anopheles, the rear end is raised

Some species of malaria mosquitoes have dark spots on their wings, but non-malarial mosquitoes do not.

The heads of males of all mosquitoes have strongly drooping mandibular antennae; in females they are weakly drooped. In females, Anopheles are equal in length to the proboscis, Culex and Aedes are a third to a quarter of the proboscis. Males of Anopheles have similar proboscis and club-shaped thickenings at the end, while non-malarial ones have a longer proboscis and no thickenings.

The scutellum of the mesothorax in falariids is rounded (entirely edged), in non-malarials it is trilobed along the posterior edge

The legs of malarials are longer.

Mosquito development cycle.

The new generation of mosquitoes hatched from pupae undergoes a maturation period (about 4 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, mate, and then the females must drink blood for the eggs to develop. They actively search for prey at a distance of up to 3 km from the reservoir, flying indoors. Having drunk blood, the females hide for several days in a darkened room or thicket. During the digestion of blood, eggs mature (gonotorphic cycle). Monocyclic (1 cycle per summer) or polycyclic (2-7). Females live for about 1 month, males for 10-15 days. After the eggs mature, the female flies to a pond and lays 350-450 eggs. Larvae emerge from the eggs, the duration of development depends on twater (15 days at 25°C), not less than 10. The larvae feed on bacteria and grow residues, molt several times and transform into pupae, from which adults emerge.

In Anophelis and Culex the fertilized females overwinter, and the eggs in Aedes overwinter. When cold weather sets in, males fertilize females and die. Females feed on blood to form a fat body, which is how the cat survives the winter. Egg development is inhibited. In the spring they feed again and lay eggs.

Differences between eggs, larvae, and pupae of malarial and non-malarial mosquitoes.

Anopheles – in standing or low-flow, unshaded reservoirs with clean water. The eggs have a belt with air chambers and float one at a time.

Aedes – lay eggs one at a time in temporary reservoirs (puddles, tin cans, hollows). Elongated oval without air chambers

Culex – wedge-shaped without air chambers, deposited on the surface of the water glued together in the shape of a boat

Culex and Aedes – on the penultimate segment of the abdomen there is a respiratory siphon in the form of a narrow tube; at the end there are stigmas (tracheal openings). Located at an angle to the surface of the water, they breathe atmospheric air

Aedes – the nature of non-simultaneous hatching of larvae from eggs of the same clutch, lasting for weeks and months (adaptation to drying up water bodies)

Anopheles – do not have a siphon, located parallel to the surface of the water. A pair of stigmas, through which they breathe atmospheric air, are located on the penultimate abdominal segment

Comma shape. On the dorsal side of the cephalothorax there is a pair of respiratory siphons. With their help, the pupae are “suspended” to the surface of the water. Culex and Aedes have cylindrical siphons, Anopheles have conical siphons

Medical significance of mosquitoes.

MosquitoesAnopheles are specific carriers and definitive hosts of malaria pathogens, specific carriers and intermediate hosts wucherer and brugi.

MosquitoesAedes– specific carriers of pathogens of Japanese encephalitis, yellow fever, Dengue fever, lymphocytic choriomeningitis, anthrax, wuchereriosis, brugioz, tularemia.

MosquitoesCule xspecific carriers of pathogens of Japanese encephalitis, tularemia and wuchereriosis.

The structure and medical significance of mosquitoes.

Mosquitoes (subfamilyPhlebotomidae) They live in countries with warm and hot climates and live mainly in human housing. In addition, they live in caves, in rodent burrows, etc. Dimensions are 1.5-3.5 mm, color is brown-gray or light yellow. The head is small. The mouthparts are piercing-sucking. The legs are long and thin. The body and wings are strongly drooping. Eggs are laid in places protected from the sun: rodent burrows, caves, tree hollows, bird nests, and garbage. Males feed on plant juices, females on blood (at dusk and at night). The bites are painful, and blisters and itching appear at the site of the bites.

Mosquitoes are specific vectors of leishmaniasis and pappataci fever. They are characterized by transovarial transmission of pathogens.

Morphology and development cycle of the housefly.

Housefly (musca domestica) widespread everywhere.

Morphological features: the size of females is up to 7.5 mm. The body and paws are dark in color and covered with hairs. The legs have claws and sticky pads that allow flies to move on any surface. The mouthparts are licking and sucking. The lower lip is transformed into a proboscis; at its end there are two sucking lobules, between which the oral opening is located.

Saliva contains enzymes that liquefy solids. organic matter which she then licks off. Flies feed on food and various decaying organic debris.

Life cycle: 4-8 days after mating at a temperature of 17-18 C, the female lays up to 150 eggs in rotting organic matter, kitchen waste, manure, human feces, etc. at the optimal temperature (35-45C), larvae emerge from the eggs within 24 hours and pupate after 1-2 weeks.

Pupation occurs in the soil at a lower temperature (not higher than 25C). A new generation of flies appears in about a month. Their lifespan is about one month.

Epidemiological significance of the housefly.

Flies are mechanical carriers of pathogens of intestinal infections (cholera, paratyphoid fever, dysentery, typhoid fever), tuberculosis, diphtheria, helminth eggs and protist cysts. There are up to 6 million bacteria on the body of a fly, and up to 28 million in the intestine.

Fighting flies lead at different stages of their life cycle. To combat winged flies, insecticides, Velcro, baits with poisons are used, and they are destroyed mechanically. To combat pre-imaginal stages, the improvement of populated areas is of great importance: the presence of sewage systems, closed garbage containers, manure storage facilities, toilets, timely removal of waste, and the use of insecticides.

Structure, life cycle, medical significance of the Wohlfarth fly.

Wohlfart's fly (wohlfahrtia magnifica) common in countries with temperate and hot climates.

Morphological features: light body gray, length 9-13 mm, on the chest - three dark longitudinal stripes

Children are especially affected by myiasis. With intense infection, complete destruction of the soft tissues of the orbit and head is possible; sometimes the disease ends in death. Occasional intestinal myiases can be caused by housefly and blowfly larvae.

Preventive measures are aimed at protecting people from attacks by flies.

Tsetse flies: morphology and medical significance.

The tsetse fly (glossinapalpalis) is distributed only in the western regions of the African continent. It lives near human habitation along the banks of rivers and lakes with high soil moisture, overgrown with shrubs and trees.

The sizes are large (up to 13 mm), the proboscis is highly chitinized, protruding forward. The color is dark brown. Females are viviparous and lay only one larva on the soil surface. The larva penetrates the soil, pupates, and after 3-4 weeks the imaginal form emerges. Over the course of their entire life (3-6 months), females lay 6-12 larvae.

It feeds on the blood of animals and humans and is the main reservoir and specific carrier of the pathogens of African trypanosomiasis.

Control measures: cutting down bushes and trees along the banks of rivers and lakes near settlements and along roads. Insecticides are used to control adult flies.

Morphology, development cycles, medical significance of cockroaches.

Squad cockroaches (Blattoidea)

Morphological features: large insects, body length reaches 3 cm.

The body is flattened in the dorsoventral direction. They have 2 pairs of wings: the upper ones are leathery, the lower ones are membranous. In females the wings are reduced. The mouthparts are gnawing type. Cockroaches have special scent glands in their skin, the secretion of which attracts other individuals, which is why they exist in large groups.

Life cycle: development with incomplete transformation lasts several months. Females lay eggs in cocoons, which they carry with them for 14-15 days. They are typically active at night and hide in crevices during the day. They are found in human dwellings, in food industry and public catering enterprises, etc. the mandatory conditions for their existence in a human home are: the presence of moisture, a certain temperature, and a sufficient amount of food. They feed on food, human excretions and various waste.

Representatives: the black cockroach or kitchen cockroach (blattaorientalis), the red cockroach or Prussian cockroach (blattellagermanica) and the American cockroach (periplaneta americana).

Medical value: mechanical carriers of pathogens of infectious and invasive diseases (typhoid fever, paratyphoid fever, dysentery, diphtheria, tuberculosis, helminth eggs, protist cysts, etc.). cockroaches can attack sleeping infants, gnaw the epidermis in the nasolabial triangle and cause infection.

Measures to combat mosquitoes, mosquitoes, flies, cockroaches.

Mosquito control measures come down to the following areas:

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

Fighting winged mosquitoes - spraying insecticides in mosquito wintering and roosting areas (basements, attics, barnyards).

Fight against larvae:

A) drainage of small reservoirs of no economic importance;

B) use of pesticides;

B) shading of reservoirs by trees;

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

D) spraying mineral oils over the surface of reservoirs, clogging stigmas;

E) breeding gambusia fish (biological control method)

Mosquito control measures: treating residential premises with insecticides, cutting off windows, using repellents.

To fight cockroaches insecticides (dichlorvos, karbofos), baits with borax are used, environmental methods are used (you cannot water flowers at night, leave leftover food, scraps on the tables, you must regularly clean the room, seal cracks in the floors, etc.)

Malaria is one of the most widespread diseases in the world. About 1 million people die from it every year around the world. The main areas where malaria is spread are hot tropical countries: Africa, Central and South America, countries of Southeast Asia, Papua New Guinea and others.

TO general information, distribution area of ​​these dangerous insects very extensive. They are found almost everywhere, including on the territory of our vast Russia. Only people living in the northernmost regions and in Eastern Siberia are protected from meeting them. Well, they don’t like mosquitoes very much low temperatures, real Siberian winters are very harsh for them.

This may sound a little ridiculous, but malaria mosquitoes are mostly found where there are outbreaks of malaria. In other areas, encountering them is very rare. These mosquitoes themselves are not dangerous until they have tasted the blood of a person with malaria.

How do they differ from our usual “blood brothers and sisters” and how to protect ourselves from this disease we will now find out.

I propose not to beat around the bush and immediately begin to consider the main signs that distinguish an ordinary mosquito from a malarial one.

First, the malaria mosquito is easily identified by its long hind legs. BUT! It should not be confused with large long-legged mosquitoes, which are kind-hearted creatures and feed exclusively on plant juices. They are completely harmless to humans.

Secondly, when landing on the surface, its body is located at a large angle to it, almost perpendicular, and all “thanks to” the long hind legs. Our ordinary mosquito behaves more modestly and tries not to stand out, placing its body almost parallel to the surface.

The wings of the malaria mosquito are decorated with small black spots - this is the third difference.

Fourthly, female malaria mosquitoes have jointed tentacles on their heads, equal in length to the proboscis. In female common mosquitoes they are much shorter. But you are unlikely to look closely at the head of a mosquito that lands on your hand, so be guided by the more obvious and simple signs listed above.

The first is the habitat. Our dear mosquitoes cannot live without water, because almost their entire life cycle is connected with it. Their childhood, adolescence and youth pass in a variety of bodies of water, from ordinary puddles to large ponds :).

Reservoirs are habitats for mosquito larvae

Most often, clean or sparsely overgrown bodies of water, which are not overgrown with duckweed and are suitable for the larvae, serve as a home for the larvae of the malaria mosquito. Acidic waters and reservoirs poor in flora and fauna are not suitable for them (since there will be nothing to eat).

But there are plenty of them in neutral or slightly alkaline waters and where filamentous algae grow, which are an excellent refuge for larvae from fish and other aquatic predators who want to enjoy them.

Malaria mosquito larva

The larvae of ordinary mosquitoes are not so picky and can live in bodies of water rich in organic matter and even in sewer water (this applies to urban mosquitoes).

The second is the structure of mosquito larvae. Malaria mosquito larvae do not have a long breathing tube at the end of the body; its role is played by sessile breathing holes.

In addition, the larvae of the common mosquito are located at a large angle to the surface of the water, while the larvae of the malaria mosquito take on an almost horizontal position. So they float quietly and peacefully on the surface from 8 days to 4 weeks. It all depends on the water temperature; the higher it is, the faster the development of the larvae occurs.

Of the approximately 150-350 eggs of a malaria mosquito (their number most often depends on how hearty the mother managed to eat), not all survive. Many of them act as excellent food for dragonfly larvae, water bugs and beetles, as well as carp, perch and some other fish. The female common mosquito lays from 30 to 150 eggs.

After laying eggs, the female turns into a vegetarian for 2 days and switches to plant juices. And then a new mating, a new “victim” and a new portion of eggs on the surface of the water.

The entire body of mosquito larvae (both malarial and common) is covered with many bristles. As they grow older, they grow from 1 mm to 8-9 mm and at each stage of development they change their color. So at first they will be black, then they gradually turn gray and in the end, before “hatching”, they become green or reddish, but sometimes they retain a dark color.

Malaria mosquito pupa

Malaria mosquitoes lead night look life and during the daytime they hide somewhere in dark, secluded places. Therefore, most of their attacks occur in the dark, when a person is sleeping.

Blood drunk female

The menu of adult females, males and their larvae is completely different. The former prefer to drink blood, in addition to 2 days of vegetarianism after laying eggs; the second - feed exclusively on plant juices, and the third - small aquatic organisms, which are caught using oral brushes and sent into the mouth opening. If there are filamentous algae nearby, they will feast on them too.

Male drinking plant juice

Females live longer than males. Their lifespan can reach up to 2 months if they are not slaughtered first. Males live for a few days at most.

How to protect yourself from malaria:

1. Mosquito nets, curtains or mats treated with a special insecticide (this is if you are vacationing in a country where there is a risk of contracting malaria).

Anti-mask nets

2. Use of mosquito coils and other fumigants (toxic vapors or gases).

3. When it gets dark, wear clothes that cover exposed areas of the body - long-sleeved shirts, pants, long skirts.

4. Reducing the number of mosquito larvae:

- using kerosene or fuel oil. If you pour a little of them into a stagnant pond with mosquito larvae, a thin film forms on the surface of the water, which prevents the larvae from breathing. After 2 days they die;

— colonization of reservoirs with fish fry that feed on mosquito larvae. Most often these are representatives of the carp family.