Every person at least once encountered this large, "biting" and "harmful" fly. But in fact, "biting" and "harmful" are two different flies: most people confuse gadfly and horsefly.

Science knows more than 150 species of these insects. All species are classified as flies, whose life is associated with human settlement: where a person lives, an insect is always found there. Scientifically, this is called synanthropization.

insect gadfly

Appearance

The size of an insect is larger than an ordinary fly. The difference from other large dipteran insects is that its head is movable, semicircular. Connects to the body with a thin stem.

The eyes are naked, in females they are more apart at the back of the head than in males. In total, the insect has five eyes, one pair of large and complex and 3 small simple eyes. Small, short and bristly antennae are located, as it were, in a dimple on the forehead.

Adults do not feed, therefore, they don't have mouthparts. The body of the insect is large, wide, there is a transverse seam on the back. There are short bristles on the body, there is also a hairy gadfly, it is often confused with a bumblebee. The insect has six legs, and the back pair is much longer. There are two wings, which is why they belong to two-winged insects. On the wings, as in ordinary flies, there are small transverse veins.

The color of an insect depends on its species. Some have an indefinite color and merge with the place on which they land (stone, rock).

Life cycle

, that is, in their development there are all stages (or phases): egg, larva, pupa, adult (imago). Let's take a closer look:

• Egg- the most primitive phase. After the formation of eggs, the female lays them, depending on the species, but most often it is the animal's food or its wool. Interestingly, when the female of some insect species is just about to lay a clutch, she makes a characteristic sound that animals hear and begin to worry. The duration of this period depends on the weather and climate, it is natural that in the north this period is shorter.
• Larva of the 1st stage. The larva ripens inside the egg from 3 days to a week, it depends on the air temperature, the warmer it is, the faster the larva will appear. And then the path to the host's body begins, how this happens is still not known for certain. Some believe that the larva penetrates the skin by drilling through it. Most people believe that through natural openings, and in the body they already migrate through the vessels, getting into adipose tissue. Scientists do not know exactly how long this stage lasts, someone believes that up to a year. It is only known that the larva increases tenfold: from 1.5 mm to 1.5 cm.
• Larva 2nd stage. In this phase, the larva gradually moves to the dorsal region, grows and gradually forms a capsule around itself, which in the next stages will become the shell of the pupa. At this stage and for further maturation, the larva needs oxygen, so it makes holes on the skin of the animal, the so-called fistulas. At the end of phase 2, the larvae molt.
• Larva 3rd stage. Here the larva gets out through the fistula to the surface and falls on the ground, where it turns into a pupa. Typically, this happens in warm time days - morning or afternoon.
• chrysalis. The transformation into a chrysalis does not occur instantly, but within a few days, sometimes a week. But the development of the insect inside the pupa occurs from one to one and a half months. The pupa itself is almost immobile in this phase.
• Imago. The further transformation of the pupa into an adult (adult) is carried out almost instantly (2-3s), and after a minute the insect can fly and mate. Since adult there are no mouth organs, the gadfly does not look for food, everything nutrients were accumulated in previous phases of larvae. It follows that the life expectancy of an adult gadfly is short - no more than three weeks (up to a month in non-flying rainy weather). Moreover, by the end of the phase, the gadfly loses weight by a third. Interesting fact researchers found: males and males fly to the same place every year, where mating takes place.

Families of gadflies

human gadfly

It is worth noting separately the human gadfly. Fortunately, it is not found in our latitudes, but is found in South America, although it is easily transferred to other countries by people in which the larva already lives.

The difference from other species is that the female lays an egg on a blood-sucking insect (mosquito, mosquito, tick, and others), and then with the bite of this insect, the larva gets under the skin of a person, where all the stages pass.

In general, a gadfly of any family can penetrate a person, so everyone needs to know how to protect themselves from a conditional “bite” of a gadfly, and most importantly, what to do if the larva has already entered the body.

Gadfly protection

The gadfly “finds” a person or animal by smell (sweat or other harsh natural amber), so it is very sensitive to it, it follows that hygiene, especially in the hot months, is simply necessary for prevention. Unlike natural odors, the smells of various special sprays repel them, as do some natural odors, such as birch tar. It has been noticed that the gadfly does not tolerate the smell of Vishnevsky's ointment.

You can notice the dangerous proximity of the gadfly by observing the behavior of the animal, it becomes restless (runs, turns its head or tail).

If a "bite" occurs, you should immediately consult a doctor. If this is not possible, you can try to cope with the larva yourself. To do this, lubricate the place where the “bite” is found with a greasy and thick substance that does not allow oxygen to pass through (glue, petroleum jelly or something similar). The gadfly larva needs air, and if it is not enough, the larva will partially crawl out to the surface. And then carefully remove it. The last step is to lubricate the damaged skin disinfectant.

The above steps apply to pets as well.

Human miases arise due to the penetration of larvae and sexually mature individuals of arthropods into the tissues and cavities of the body. Most often, the causative agents of the disease are:

• a tumbu fly that penetrates under the skin and forms peculiar tunnels there;
• sand flea, hoverfly fly and raznopodzhka, able to penetrate under the epidermis and lay eggs;
• carrion, cheese and wolfart flies infecting damaged skin and mucous membranes;
• small housefly, green, gray meat and fruit flies, can affect the intestines, ears and genitourinary system;
• cavity sheep gadfly, affecting the organs of vision;
• blowfly in the respiratory system.

The most common route of infection is through damaged areas of the skin and mucous membranes. Insects can lay their eggs in the eyes, ears, nose, wounds or sores. Some varieties of flies are able to introduce their future offspring subcutaneously.

Consumption of contaminated foods that have not been properly processed can also cause the development of myiasis.

Fact: unlike sexually mature individuals, larvae do not respond to the effects of most chemical substances. This explains their ability to stay in the intestines, duodenum and bladder for a long time.

Disease classification

First of all, myiases are classified depending on the type of flies that cause the disease:

In addition, the disease caused by the larvae is systematized depending on the location. There are tissue, cavitary, ocular and intestinal myiasis.

Tissue myiasis: forms, symptoms, treatment

The cutaneous form of myiasis is most often found in people living in unfavorable sanitary and hygienic conditions. The disease can be caused by the larvae of eighteen species of flies, as well as the sand flea. Insects are securely attached to the skin, make tunnels in it and place their larvae there. In addition, infection can occur through open wounds and ulcers.

At the first stage of development, it is extremely difficult to diagnose the disease. However, there are main symptoms, the appearance of which requires immediate medical attention:

Important! It is impossible to get infected with the cutaneous form of myiasis from a sick person. Infection occurs upon contact with an insect, soil inseminated by larvae, sand, products, while caring for sick farm animals, on the wool of which larvae are present.

Cochliomiasis is diagnosed by external examination, ultrasound, magnetic resonance or computed tomography. Samples are taken from the affected area for biopsy, and a blood test is also taken.

the only safe method extraction of larvae in the cutaneous form of myiasis is a surgical intervention. After the operation, the patient is put on an antiseptic dressing, and antibiotics are prescribed.

Cavitary myiasis: localization, symptoms, treatment

The cause of the development of cavitary myiasis, as a rule, becomes Wolfart, small house and house flies, sheep and bovine gadfly. In this case, the larvae can be localized in such places of the human body as:

• oral cavity and gums;
• auricles and ear canal;
• bladder and urinary tract;
• sexual organs.

Miasis in the mouth is quite rare. The disease can occur due to neglect of the rules of personal hygiene, pustular formations in the mouth, increased salivation, a decrease in the protective mechanisms of the immune system against the background of alcoholism and adulthood.

Please note: Infection with fly larvae in young children can occur through dirty fingers that the baby constantly sucks.

Oral cochliomiasis is accompanied by the following symptoms:

• twitching of gums and cheeks;
• bleeding of the gums increases, painful sensations appear;
• the appearance of ulcers on the mucous membrane and bad smell from mouth;
• unbearable toothache when chewing solid food;
• nasal congestion;
• the appearance of allergic reactions;
• deterioration in general well-being, fatigue, loss of strength;
• in advanced cases, persistent fever may occur.

Infection of the genitourinary system occurs through dirty underwear or bed linen infected with larvae.

Eye myiasis: symptoms, treatment

Ophthalmomyiasis is treated exclusively by surgery with the use of painkillers. After successful surgical work, patients are prescribed washing with soda and boric solutions, as well as taking antibiotics, anti-inflammatory drugs and applying antibacterial ointments to the incision area.

Posterior internal ophthalmomyiasis is treated with vitrectomy (removal of part or all of the vitreous body of the eye) or photocoagulation, which leads to the complete destruction of the larvae.

Intestinal myiasis: symptoms, treatment

Intestinal myiasis develops as a result of eating foods infected with pathogenic organisms. In rare cases, they can enter the body through the anus: flies lay their eggs in the anus, they are absorbed into the mucous membrane of the intestinal tract, and then enter the circulatory system and spread throughout the body.

The presence of pathogenic organisms in a person causes the following reactions of the body:

• frequent vomiting, nausea;
• intense, pronounced pain in the epigastric region;
• pain in the peritoneum;
• the appearance of hemorrhage (bleeding, hemorrhage, bloody impurities in the feces);
• development of colitis;
• symptoms similar to typhus: fever, pallor of the skin, impotence, loose stools, the appearance of a whitish coating on the tongue, slowing of the heart rate, confusion.

The disease is difficult to diagnose based solely on the symptoms. To confirm intestinal cochliomiasis, conduct clinical studies of feces and vomit.

Prevention

Main preventive measures myiasis are:

• observance of elementary rules of hygiene;
• timely treatment of ulcerative lesions and violations of the integrity of the skin;
• protection of foodstuffs from flies;
• high-quality food processing;
• timely treatment of domestic and farm animals.

At the slightest sign of myiasis, it is worth contacting a specialist. The disease cannot be cured on its own, and prolonged ignoring of the symptoms can lead to death.

Being at the first stage of their development, the larvae are constantly in the body of their carrier. With the approach of the second phase, before the molt itself, they find themselves in the back area. During this period, nodules with fistulas - outlets will be visible on this part of the animal's body. Thanks to them, the larvae of the gadfly, which are under the skin, get the opportunity to breathe, and after a while they go out through these very holes.

Harm to livestock

The breeding cycle of the bull gadfly begins around June and ends in September. At this time, fertilized females are especially active, being in search of a potential victim.

On a note! Gadfly larvae emit a special toxic substance- hypodermotoxin. Together with the meat and milk of an infected animal, it can enter the human body, having a negative impact on health!

Fistulas that speak of the presence of hypodermatosis can be found on the body of animals from the last month of winter to the middle of summer. At the same time, the larvae are able to exist in their capsules for quite a long time - about 1-3 months. After emerging outside, they fall to the ground, usually in dung, where they turn into pupae.

On a note! At the same time, even insects that have fallen to pupation are dangerous - only 10 larvae, which are at the third stage of their development, can infect about 40% of the livestock!

Consequences

Infection with a subcutaneous gadfly leads to the following consequences:

• In cows - a decrease in milk yield by about 7%.
• Juveniles have stunted growth.
• For the leather industry, the skin of animals that have suffered hypodermatosis has holes that spoil the raw leather.
• For the meat industry, the capsules in which the larvae developed must be removed, due to which a sufficiently large amount of meat is lost, sometimes, with severe infection, about 10% of the raw material has to be cut out.

If signs of infection are found, animals are slaughtered exclusively at sanitary slaughterhouses.

Prevention

In order to prevent the spread of bovine gadfly, animals must be periodically examined for the presence of fistulas.

1. In the period from March to May, it is advisable to carefully palpate the backs and lower backs of cows and horses - this technique will allow you to detect subcutaneous nodules in time.
   

   Important! If nodules are found, contact your veterinarian immediately!

2. For prevention purposes, at the end of summer or at the beginning of autumn, cows and horses are treated with special preparations, the action of which is aimed at destroying the larvae that are at the first stage of development. Moreover, absolutely all livestock is processed, including animals that are the property of individual owners.
3. In order to prevent the penetration of gadfly larvae under the skin after their emergence from eggs, it is recommended to graze animals during the grazing period until 10.00 and after 18.00. In the daytime, it is desirable to keep cattle under sheds or indoors.

Danger for pets

Gadfly larvae can also appear in a dog. The most likely sites of infection in this case are areas where tall grass grows and there may be a sufficient population of rodents.

Treatment

Prevention

If your pet has weak immunity, then infection with the larvae of the subcutaneous gadfly can occur annually. To prevent this, you can resort to the following preventive measures:

Human danger

In addition, as a result of its vital activity, the larva of the subcutaneous gadfly provokes the development of dermatobiosis. This disease manifests itself in the form of nodes that occur in the area where the insect is present. These nodes can become inflamed and cause suppuration. After some time, mature individuals leave the body of their carrier.

Prevention

Preventive measures are quite simple:

• being in countries where Dermatobia hominis lives, it is advisable to use drugs that protect against insect bites;
• at the same time, it is desirable to wear clothes made of dense fabric with long sleeves and full trousers.

If a bite site is found, it must be treated with an antiseptic and seek medical help.

Myiasis is a disease caused by fly larvae that are common in Africa, New Guinea, California, Mexico, and also South America. This disease got its name in the 19th century thanks to the work of a priest named Frederic Hope. A person can become infected with myiasis only in favorable conditions for flies, namely, unsanitary conditions, by eating low-quality, semi-decomposed foods, working on the ground, where fly eggs can also fall.

The following types of flies are considered to be the causative agents of various kinds of myiasis:

• tumbu fly or Cordylobia anthropophaga;
• sand flea or Tunga penetrans;
• Wolfart fly or Wohlfahrtia magnifica;
• Russian gadfly;
• sheep gadfly.

Depending on the place of introduction into the human body, myases are divided into the following groups:

• superficial;
• deep;
• cavity.

Superficial myiases

This type of disease is provoked by the larvae of such flies:

1. meat.
2. carrion.
3. cheese.
4. room.
5. brownies.

deep myases

Deep myases are usually referred to as:

• ordinary deep myiasis;
• African myiasis;
• South American miaz.

cavity myiasis

This group includes myiases, the pathogens of which prefer to settle:

1. in the mouth.
2. in the ears.
3. in the organs of the genitourinary system.
4. In eyes.

Ingestion of fly larvae due to the consumption of low-quality food provokes intestinal myiasis. Typical symptoms for this type of disease are:

• nausea;
• vomit;
• diarrhea;
• blood in faeces.

The occurrence of myiasis of the genitourinary system can be caused by elementary non-compliance with the rules of personal hygiene (wearing dirty linen). Thus, the larvae penetrate the organs of the genitourinary system, provoking symptoms:

1. vulvitis.
2. vaginitis.
3. urethritis.
4. cystitis.

Timely diagnosis of the disease and the provision of qualified medical care is the main guarantee of successful treatment of myiasis.

First you need to consult a dermatologist. In severe forms of myiasis, the help of a surgeon may be required.

Cutaneous myiasis can be diagnosed by examining a patient's purulent wound with a magnifying glass under bright light conditions. Intestinal myiasis can only be detected by examining the patient's secretions. Miases in the organs of the genitourinary system can be detected by a gynecologist when analyzing a smear taken from the genitals. An ophthalmologist will help diagnose myiasis of the eyeball.

Treatment

Intestinal myiasis is treated with anthelmintics. Sometimes gastric lavage is required. When the larvae penetrate the organs of the genitourinary system, the doctor prescribes local therapy with antibiotics or antiseptics. Removal of pathogens that are based in the eye area is carried out under anesthesia. Then the patient should wash his eyes with a weak solution of soda for several days.

As rehabilitation measures, the patient is shown to drink plenty of water, the use of special ointments (for skin myiasis).

Forecast

The consequences of most myiasis, as a rule, are favorable for the patient, since over time the larvae themselves leave the host's body in order to continue self-propagation in the soil. Subject to timely diagnosis and qualified medical care most superficial myiasis resolves without complications. However, deep miases can cause dysfunction of internal organs, blindness, and even death.

Prevention

To avoid such an unpleasant disease as myiasis, one should strictly adhere to the rules of personal hygiene and food hygiene. Bed and underwear should be washed with disinfectants in hot water. It needs to be dried fresh air. As an additional security measure, iron it.

Food should be thoroughly washed before eating. running water, expose heat treatment. It is advisable to peel them. Spoiled meat or vegetables should not be eaten. Food must be stored in the refrigerator. It is advisable to eat food in the house, and not in the fresh air, where insects have access to it. It is advisable to buy products not from hand, but in stores where meat is stored in a closed refrigerated showcase and before hitting the counter passes sanitary control.

Open wounds must be treated with antiseptics immediately after they occur. Better yet, see a doctor right away.

Among over 150 species of gadflies, only one, called Dermatobia Hominis, is dangerous to humans. It cannot be found in Russia and the CIS countries - the insect is found only in countries with a tropical climate: Central America, Argentina and in some parts of Mexico. The gadfly larva in a person can cause a lot of unpleasant phenomena: inflammation, suppuration, disruption of the normal functioning of body systems, and surgical intervention may be required to remove it.

How can a larva enter the body?

An adult gadfly is a fly, the size of which does not exceed 18 mm. It has a large head with large eyes located on it, a blue abdomen, painted in Orange color paws and transparent wings. Because of the hairs all over the body, the gadfly resembles a bumblebee.

An adult insect throughout its brief life does not feed on anything, but uses the nutrients accumulated in the larval phase.

30 seconds after the exit, the adult gadfly becomes capable of flight and reproduction. One female can produce up to 700 eggs, but the larva appears from only 1/5 of them.

Female human gadfly with eggs

The female catches mosquitoes, ticks and almost 40 species of other blood-sucking insects and lays eggs on their abdomens. At the moment when the insects land on human skin, the larvae, feeling warm, hatch from the eggs and move to the skin, into which they are subsequently introduced. Penetration into the body is not accompanied by any painful sensations, and most often remains unnoticed by a person.

About 6 species of gadfly are common on the territory of Russia, and all of them prefer to choose cattle or horses as their host. However, cases are occasionally recorded when larvae are found in humans - in the eyes or under the skin.

The larva can penetrate into any part of the human body: arms, legs, chest, head. However, most often she chooses legs, back and armpits. Sometimes the larvae settle in the eyes and nose.

After some time, the area of ​​​​the skin becomes inflamed, sore, swelling of a bluish or reddish tint appears. An abscess is formed, which after a while opens up. Due to this, a hole is left in the skin, which provides the larva with air flow. When the abscess opens, pus comes out of the wound.

Gadfly larvae in the human body cause a deterioration in well-being: vomiting, dizziness, muscle pain and fever appear. At the site of the focus of inflammation, movement under the skin can be felt.

Important! Larvae not detected in time are able to penetrate the vitreous body or the anterior chamber of the eyeball, and this is fraught with partial or total loss vision.

When it enters the nose, a headache develops, the sense of smell worsens, a pain sensation appears in the nose, swelling of the nose and mucous membranes is formed. The larvae can even go out through the nostrils.

What harm do they do to the body?

Possible complications - the development of a secondary infection.

How is a larval infestation treated?

The disease caused by the larvae of the human gadfly has a name - dermotobiasis.

Diagnostics

To diagnose the disease, a blood test is used to determine the amount of antibodies. The patient will be asked if he has been to places where the disease is spread. A visual inspection is also used, during which a purulent abscess with a hole is found on the skin. The doctor examines the focus of inflammation with a magnifying glass.

Medical treatment

Extraction of the larva

After the successful completion of the procedure, an antiseptic bandage is applied to the damaged area of ​​the skin.

When traveling to countries with a tropical climate, you should take precautions: wear protective clothing against insect bites, use repellents. If the bite blood-sucking insect could not be avoided, it is necessary to carefully treat the wound with a disinfectant, monitor its condition and consult a doctor at the slightest deviation from the norm.