Gadfly larva in man: symptoms, effects, removal — Insects
Insect gadfly how it looks and what is dangerous for humans
- 1 Insect gadfly how it looks and what is dangerous for humans
- 2 What is the gadfly larva?
- 3 What types of gadfly exist?
- 4 How can a parasite get into a human body?
- 5 Does this parasite exist in Russia and can they be infected?
- 6 Symptoms when the parasite is under the skin: what are they?
- 7 How is the diagnosis made?
- 8 How does the treatment occur when the larvae are infected?
- 9 Gadfly larvae removal: how does this happen?
- 10 Infection prevention
- 11 Description and habitat
- 12 Appearance
- 13 Life cycle
- 14 Propagation of gadflies
- 15 Can gadfly larvae enter human body?
- 16 What are dangerous gadfly?
- 17 How to protect yourself?
- 18 Development phases
- 19 Subcutaneous larval migration routes
- 20 Types of gadfly by animal type and organ parasitism
- 21 Pairing
- 22 Where and when to meet with the gadfly?
- 23 Gadfly harm
- 24 Symptoms and effects of a gadfly bite
- 25 First aid for biting gadfly
- 26 How to avoid meeting the gadfly and how to defeat it
- 27 What kind of insect is a gadfly and how does it look
- 28 Gadfly classification
- 29 Ways of infection
- 30 Признаки заражения личинкой овода
- 31 Treatment of parasitic infections caused by gadfly
In the world there are about 150 species of gadfly larvae. Fortunately, only one of them is dangerous for humans. Its habitat is the territory of the planet Earth with a tropical climate. In general, this parasite is very dangerous if it enters the human body. Therefore, you should be careful, and when the first signs appear, immediately and immediately contact a specialist.
What is the gadfly larva?
It is a parasite that basically develops and grows under the skin of a person or animal. Gadfly larva resembles a pear with spikes on scales. Their length is short — a little less than 30 mm, and the diameter is about 8 mm. The parasite feeds on blood. That is why it is dangerous in case of penetration into the human body. This harmful microorganism attaches to mammals with burrs. And in this way it feeds, that is, it accumulates useful substances for its further existence, life activity. In addition, it can, after penetration into the body of a mammal, release a kind of liquid that causes severe pain.
What types of gadfly exist?
Types of this parasite a huge amount. Experts agreed to divide them by habitat. Each species of larvae has its own characteristics. Some of them are dangerous for the owner and for his body. There are 4 types of parasites: subcutaneous and dermal, abdominal and stomach.
The first type is dangerous for both humans and animals. If delayed treatment may have dire consequences.
The second type is characteristic of a bovine gadfly. He, of course, is not dangerous, as the first kind, but still, if this happened, boils form on the body of a person or an animal. In addition, there are severe pain. After pus may be released.
Cavity species is most common in goats. The larvae are located first in the nostril, and then penetrate into the respiratory tract.
Gastric gadflies most often in horses. It develops in their stomach, and then goes to the tongue and gums. There are pustules.
How can a parasite get into a human body?
The adult gadfly larva is a fly. Its size is about 2 cm. It is somewhat similar to a bumblebee. But in order to distinguish it from this insect, there are a number of signs:
- big head,
- large eyes,
- blue belly,
- orange paws,
- transparent wings.
The grown parasite does not eat anything, but feeds on the substances that it has accumulated when it was still a larva.
Within half a minute after the release, the adult gadfly can fly. A female produces about 600 eggs. But, fortunately, only 1/6 survives.
An adult parasite catches blood-sucking insects, and then leaves its eggs on their abdomens. And if the mosquito on which these larvae sit on a person or an animal, then they penetrate into their bodies. People do not feel any pain or discomfort.
Parasites that have matured have special devices — hooks. With their help, they are attached to the skin. Gadfly larvae in humans feed throughout their stay in blood and grow up to 2.5 cm. In total, this parasite lives in the body of a mammal for about 9 weeks. Then he goes outside and falls to the ground, where the pupation process takes place. A month later, an adult appears.
Does this parasite exist in Russia and can they be infected?
There are about 7 species of larvae on the territory of our country. Mostly they live in the body of cattle. There are cases when gadfly larvae were found in a human body in Russia. Their favorite place to stay is their eyes or skin.
Of course, the percentage of cases of finding this parasite in humans is very low, but you should beware of these harmful creatures. You should be aware of and know the signs of the disease when they enter the human body.
Symptoms when the parasite is under the skin: what are they?
A gadfly larva in a person can be anywhere. For example, it can be found on the arm, on the chest, on the leg, and even on the head. But the most favorite places of their habitat are armpits and back. It also happens that the gadfly larva in the body is in the nose or the eye.
As a rule, at first, the person does not experience any complications and discomfort. In the place where the parasite penetrated, a small bump appears, resembling a mosquito bite. After passing a certain amount of time, this area begins to hurt and become inflamed. After it becomes blue or red. Then an abscess forms, which is opened. Thus, for the gadfly larva, a hole is formed under the skin of a person through which the parasite breathes. As soon as the inflamed area is opened, pus starts to stand out from it.
After that, a person’s condition begins to deteriorate sharply. Nausea or vomiting, weakness and dizziness, pain in the muscles are the main symptoms of the penetration of the gadfly larvae into the body. On the site where there is inflammation, the patient may feel something moving.
When these harmful parasites hit the eyes, irritation of the mucous membrane is felt, and eye pressure increases. There is a constant tearing. In addition, pain and bleeding can join all these symptoms.
Very dangerous is the penetration of the larvae into the vitreous body of the eyeball. Then a person can lose sight altogether.
When the parasite is in the body, the following symptoms are present:
- deterioration of smell,
- swelling of the nose
- pain in the location of the larvae.
Surprisingly, these harmful microorganisms can crawl out through the nostril.
How is the diagnosis made?
The main method is considered to be a blood test. It is determined by the number of antibodies. The patient is also asked a series of questions. For example, they ask whether it was in places where the disease is common. In addition to all this, the specialist conducts a visual inspection. With this method, you can detect an inflamed purulent abscess. It has a hole through which air flows. The doctor examines the site with a special device, namely a magnifying glass.
If you are sure that there are gadfly larvae in your body, then you should turn not to the therapist, but to the infectious disease specialist immediately.
How does the treatment occur when the larvae are infected?
After penetration into the human body of these parasites, certain signs of a disease called dermatobiaz appear. The treatment itself involves the direct removal of the larvae from the body of the patient. But immediately this can not be done.
Before removing the gadfly from under the skin of a person, you need to drink the drug «Ivermectin». It is antiparasitic. Only then can we proceed to the next step.
Gadfly larvae removal: how does this happen?
Before removing the parasite from under the skin of a person, it is necessary to subject the abscess to decontamination. This is done, as a rule, using furatsilina solution. In order for the larva to not be able to breathe, a certain amount of sterile oil drips from the hole from where the air flow penetrated. After that, the gadfly should come out, as it lacks oxygen. At that moment, when the parasite is shown from the hole under the skin, it is pulled out with the help of a special device (tweezers).
Complicated operation should be performed only by a specialist. The gadfly itself is located in very deep layers of the epidermis. As mentioned above, it is located there thanks to the hooks. If the patient himself tries to perform the whole procedure, it is possible that a part of the larva will remain under the skin. With this outcome of events, suppuration and an inflammatory process will follow.
As soon as the operation is completed, an antiseptic dressing is applied to the place where the boil was before.
But most often, the gadfly larva penetrates the skin of a person in countries with a tropical climate. And if you decide to go there, then follow a few simple rules. Avoid places where a large number of insects live. Of course, you need to wear clothes that protect against bites. Now in stores a huge selection of good repellents. They should also be used.
If, for example, an insect has bitten you, do not panic ahead of time, but you should not forget about it either. First, the wound should be treated with a disinfectant. And watch her. If something went wrong, you should immediately contact a specialist. The doctor will examine you, if you confirm the diagnosis, he will send you to the appropriate procedures, and if you do the opposite, you can safely return home. And do not forget that vigilance has not prevented anyone.
Description and habitat
Gadfly is the common name for many species of Diptera parasitic flies that lay their eggs on large mammals. In some regions, these insects are also called pauts.
Gadflies live on all continents, except for cold Antarctica. Most of them are in warm and temperate climatic zones. Although in Russia such insects can be met in the Urals, in Siberia, and in the north of the country.
Gadflies settle near pastures, livestock farms, grazing sites and animals. Often scour the meadows, fields, forests. In large quantities are found in areas near rivers, swamps and lakes, because they love moisture, heat and sun.
For reference!In fact, gadflies do not live only where the freezing temperature is constantly kept.
More than 150 varieties of gadflies can be found on our planet. But they all have common features in their appearance and body structure:
- Length — from 1.5 to 2 cm.
- There is no oral apparatus (or it is reduced).
- The torso is rather furry.
- The eyes are big.
- The body is wide and rounded, not much elongated.
- Hind legs longer than the front.
- The wings are translucent, with a large grid.
You can see this insect in more detail in the photo below. On them the image of a gadfly is approached as if you are looking at it under a microscope.
As for the coloring of the body, it can be different. In the northern latitudes, there are instances whose colors are of dark brown, grayish, and blue. In the south and in the tropics, vodvoda are more like trips to miniature bumblebees, and their “skin” is replete with orange and black stripes.
For reference!It is believed that the gadfly can fly at a speed of 120-140 km / h. That is, along with dragonflies, it is one of the fastest insects in the world.
The life span of this winged — about a year. And during this time, the gadfly goes the following way of development:
Surprisingly, an adult gadfly does not feed. How does he exist? When the insect reaches the stage of imago, it continues to function at the expense of stocks, which are “fed” by being a larva. As a result, during the life of the gadfly loses up to 30% of the weight, and then dies due to severe depletion.
Adult individuals do not live long — from 3 days to a couple of weeks. Much depends on the weather: if it is cold and rainy, the females do not fly, but hide. Consequently, their power reserve is not spent. But if it is warm and dry, then gadflies try to lay all their eggs literally in a couple of days, in order to die later with a sense of accomplishment.
The period of activity of these flying insects depends on the climate and terrain. If the summer is long, then the gadflys behave lively longer. On average, in Russia they are active during all the summer months (although in the south their flight begins already in April — May). In September, there is a sharp decline. After all, these flies do not like cold weather. By the way, if you notice that there are fewer gadflies in the district or they have completely disappeared, then it’s time to get ready for frosts.
For reference!Some species of abdominal gadfly are viviparous and do not go through the full developmental stage from egg to imago.
Propagation of gadflies
Most of these winged offspring as follows:
- Adults mate. The female has eggs that she needs to set aside (up to 700 pieces at a time). For laying, the gadfly usually chooses the abdomen, back, groin and thighs of the animal.
- As a result, the female catches them to the hairs of wool on the body of cattle (less often horses, sheep, rodents, dogs, etc.). After which, under the action of heat from the animal, the larvae form. Of course, not all egg-laying survives. Only every fifth egg.
- Being on the body of the larvae can be quite a long time, holding on to special spikes. But their main goal — to get under the skin of the owner. How do they do it? Usually they simply dig into an unhappy animal. After all, the larvae secrete a secret that helps them easily pass through the tissues and epidermis.
- The larva itself in the first stage is very small. The length of her body is 1.5-2.5 mm. But it actively feeds on blood, mucus, various useful substances and grows rapidly, increasing in size several times.
- Having reached the second stage and getting stronger, the larva releases two spiracles that extend at the level of the epidermis. She needs them to make holes (fistula) and provide oxygen.
- In the resulting fistula, a capsule of connective tissue is formed. In it, the insect matures to the pupal stage and is selected outside.
- In turn, the pupa turns into an imago — an adult. This process takes from 20 to 40 days.
Thus, the most common in the world of subcutaneous gadfly breeds. But there are also such species that tend to lay eggs on forage plants, mouth, lips, and those parts of the body that love to lick or scratch an animal. As a result, the larvae penetrate the stomach. There, they also parasitize the host organism, and then go out naturally and pupate.
Gadflies that spray their offspring into the nostrils and eyes of cows, horses, deer or other large animals are also common. Following their larvae, they release a certain amount of nutrient fluid so that they can develop at first — until they can parasitize another’s organism.
As you can see, there are many ways of penetration of pests into the body of a mammal. The larvae, once there, develop and grow. Then leave the body of the owner and pupate.
It is noteworthy that the process of emergence of adult gadflies from pupae is very short. It takes only a few seconds. And in less than a minute a fly that has appeared can fly and mate in order to postpone a new offspring.
For reference!Gadflies in the winter do not fall asleep. They just die, postponing offspring. It turns out that in the cold season only the larvae live, and then closer to the summer they turn into adult individuals.
Can gadfly larvae enter human body?
The answer is yes. True, insects usually cannot lay them directly on the human body. For the most part, so-called «intermediaries» are used for this. Gadflies catch a midge, mosquitoes, ticks and stick their eggs to them. After that, a different midge flies on and bites people. At this moment there is a risk that one of the eggs will get in through the appeared wound.
There is also a special type of gadfly, which is actively “practicing” the scheme described above. It is called Dermatobia hominis. This gadfly is found only in the countries of South and Central America.
Although cases of penetration into the human body of larvae of sheep, bovine or horse gadfly have been recorded. So be careful.
What are dangerous gadfly?
These flies are a great danger for livestock:
- Firstly, they pester animals with their intrusiveness, making them nervous, eating poorly and constantly moving, which worsens milk yield and weight gain.
- Secondly, gadflies lay their eggs in their bodies, which in a short time turn into gluttonous parasite larvae. Those in large quantities absorb nutrients, stock up on them for future use, cause serious illness, loss of vision, and sometimes the death of the animal.
- Third, gadfly larvae can migrate through the body, destroy blood vessels, damage nerves and cause internal bleeding or paralysis.
These parasites are also dangerous for humans. After all, the gadfly larvae actively feed on the host’s resources, deprive it of energy, vitamins, and nutrients. Infection with them is fraught with the appearance of:
- skin irritations
- vomiting and other unpleasant conditions.
A large number of such parasites within the body and their migration may result in more negative consequences. “Neighborhood” with gadfly larvae often develops into serious diseases — secondary purulent infection, pneumocephalus, meningitis, stomach ulcer, erosion of the nose, face, eyes.
How to protect yourself?
In order not to become a “house” for gadfly larvae, the following measures should be taken:
- Choose the right clothes so that insects cannot bite you and gain access to your body.
- Observe personal hygiene. Especially after the attacks on nature, hiking in the forest or visiting horse farms and farms. In such places, the risk of becoming the owner of the parasitic fly larvae is very high.
- Use mosquito nets on windows. Тем самым вы не пустите разных кровососущих насекомых, которые могут переносить на себе яйца овода.
- Обрабатывайте одежду и тело специальными препаратами. Это могут быть репелленты в виде спрея или аэрозолей, кремов или лосьонов.
- Применяйте против овода на дачном участке или ферме специальные ловушки. Although some people successfully practice and popular methods of protection (the smell of spruce needles, bird cherry, mint, cloves, etc. scares parasites).
- Spend a daily routine inspection of livestock and animals, combine it with wool cleaning and processing with special agents that can scare away gadflies (even Vishnevsky ointment or diesel oil can help here).
Gadflies are insects with a complete course of a closed transformation chain: egg-larva-pupa-imago. The whole cycle manages to go through and complete the stages within one year.
Eggs lay female gadfly in certain places on the body of the animal.
In the first stage, the larvae form and develop within 7 days at optimum temperature for the development of about 30 degrees. In such a warm atmosphere, all deposited larvae will ripen in 3 days and go further under the skin of the animal.
The larvae of the second stage of the esophagus and the spinal canal migrate to the back, where they form in the connective tissue capsules. For development, they now need oxygen replenishment, and they form fistulous openings in the skin of the animal’s back. Then they have a peculiar molt and a transition to the third stage.
The third stage larvae begin to pupate in the morning. The larvae that have fallen out of the body of livestock, while inactive and on the phase of pupation they have from 2 to 7 days. The development of the pupa occurs on average during the month.
Extracts of the midgut from the larvae of stage I (row and esophageal subspecies) are characterized by a strong dermatolytic property, which facilitates penetration through the skin of animals.
Subcutaneous larval migration routes
Researchers believe that the larvae of the row (1st stage) after cutting through the skin the animal moves along the vessels and nerve endings, looking for the path to the spine, then through the holes between the vertebrae they enter the adipose tissue of the spinal canal. The larvae of the esophagus (stage 1) move toward the esophagus and settle in its submucosal layer.
Locally affecting the esophagus and spinal canals, gadfly change the timing of their stay in the animal’s body every year differently, it depends on the time of flight. Larvae grow, eating animals from the inside, from 1.5 to 17 mm.
Types of gadfly by animal type and organ parasitism
It is for the place where the larvae parasitize, the types of gadfly differ.
Gadflys are skin, cavity, stomach.
Gadfly skin (type Hypoderma bovis) has the second name gadfly. His female is capable of sticking laid eggs to the hairline on the legs of cattle. Larva, being in close proximity to the skin, coming out of the egg shell, bites through the skin, makes a move under it and goes to the tissues of the esophagus.
Further to the tissues of the back and it turns out there in the form of large painful nodules. These sores are then dissected, and in each is the larva spiracle. Having drunk on the animal’s tissues, the mature larvae fall out of the nibbles on the ground, pupating there. Over time, the pupa makes it possible for an adult large insect to appear, and the chain of development repeats again.
In addition to the endless pain delivered to the animal, the larvae completely depreciate the livestock skin, as it turns out to be completely perforated.
If the animal has crushed the larva in any way under the skin, then a disease (Rosenfieber) and even shock due to anaphylaxis can develop.
Known cases of parasitism gadfly Hypoderma bovis and in humans. The 2nd and 3rd stage larvae were identified under the skin and even in the human eye.
Among cavitary gadflies, the sheep gadfly (Latin name Oestrus ovis) is known, which has a peculiar life cycle, similar to Rhinoestrus purpureus.
In sheep, this parasitic gadfly destroys the ethmoid bone and causes brain pressure in the membranes.
Gadfly oestrus ovis was detected when it was laid in a person’s eyes.
The delayed larva feeds on soft internal tissues from three to nine months.
For example, on the reindeer of northern latitudes, a gadfly, called the northern subcutaneous, parasitizes. The invasion of gadflies on deer is accompanied by a massive laying of the larvae, and at the time of skin drilling, the animals simply lose their strength, the weak even die.
Gadflies that are “practiced” on the digestive system, so lay eggs to get into their mouths, and then further, into the stomach, where they are particularly comfortable to develop.
There are known types of so-called nasopharyngeal gadflies that climb inside the animal through the nostrils. Many types of parasitic gadfly do not care at all what animal to cling to and settle in, but there are also electoral types. The same sulfur subcutaneous is interested in deer, a sheep gadfly picks sheep, a gadfly hook picks horses or donkeys.
The gullet of the gastric (Latin name Gasterophilidae) is a family of gadflies, parasitizing on domestic animals, on humans (in a state of larvae). Horsefly (the Latin name Gasterophilus intestinalis) of up to 16 mm in size is one of the common species.
The female gadfly awaits the fertilization of eggs, after which it is time to find the animal victim. The female gadfly in its abdomen stores up to 7 hundred eggs, which will soon be reborn into gnawing larvae.
Because of such an increased fecundity of females, the species can easily exist even with a small number of adult insects.
The timing of the beginning of the flight and its duration depends entirely on the region of residence of individuals. Longer flying in warmer areas, less — in northern latitudes.
Fight gadflies may be preventive measures: good care, nutrition, timely cleaning of the skin of livestock from adhering eggs of pests.
If you have strange growths on a lemon, then you should know — this is a shield. How to get rid of it, read here.
Where and when to meet with the gadfly?
The duration of the activity of gadfly depends on the climatic zone to which this or that area belongs. The longer the summer, the longer this period. In Russia, it takes about three months — from June to August. When the gadfly insect disappears — it’s time to prepare for the cold.
The gadfly is most active in dry, hot weather. In the open sun, it turns into a real monster, but does not like cloudy moisture.
The habitat of the gadfly habitat is the coast of natural reservoirs, as well as forest and steppe. Often these insects take a fancy to themselves certain areas where a large number of females accumulate. Naturally, the males also fly here. Usually, such sites are places of permanent cattle or marshlands. From them, a person should stay away.
The gadfly poses the greatest danger, of course, for livestock. Getting into the body of an animal, insect eggs very soon turn into gluttonous larvae, which simply eat their “home” from the inside.
They absorb excessive amounts of nutrients, accumulating them for future use, cause diseases of the gastrointestinal tract, and sometimes death of the animal. In addition, growing up and striving to «go out», the larvae of some species of gadflies gnaw holes in the skin. Thereby causing pain and making it unsuitable for livestock skin.
Scientists have long proven that cows exposed to constant attacks of gadfly, produce significantly less milk than their more lucky «companions.» The annoying insects unnerve animals, cause their stress and do not allow them to eat normally — hence the low yield.
And the bites of gadflies can harm not only the cows, but also man.
Symptoms and effects of a gadfly bite
Gathering on nature on a hot summer day, it should be remembered that there could be a dangerous gadfly there. Insect human bite produces not so unnoticed.
Usually, “planning” to make an attack and approaching the intended victim, this fly buzzes very loudly and unpleasantly. So, in principle, there is a chance to dismiss it. But if the bite did occur, the following symptoms show it:
- a bright red spot on the skin with a diameter of one millimeter or a little more,
- severe burning, itching in and around the bite site,
- the blood that you can’t stop for a long time
- large edema, formed some time after the bite (especially often — on the face in the eye area),
- deterioration of health, symptoms of intoxication in case of numerous bites (it happens that gadflies attack a group).
Often, after a bite, a person develops allergies or dermatitis. And more often, swelling grows to enormous size and does not pass a few days. To prevent this, you should immediately after the unsuccessful contact with insects to take appropriate measures.
First aid for biting gadfly
If all the symptoms of a gadfly bite are present, the following is recommended:
- thoroughly wash the affected area with water (with soap and water),
- to remove dirt, you need to drop a little hydrogen peroxide into the hearth of the bite or smear the area with green paint,
- if the bite caused severe pain, you can take painkillers,
- in the absence of medicines, the use of natural “helpers” is allowed, for example, the juice squeezed from the chamomile stalk effectively anesthetize and act as an antiseptic,
- if the bite begins to swell, it is advisable to take antihistamines that prevent the spread of infection,
- the bite site must be monitored for at least 24 hours,
- it will not be superfluous to go to the doctor, because gadflies often become carriers of dangerous infections, so it is better to be safe.
How to avoid meeting the gadfly and how to defeat it
In this world, nothing is impossible, and you can meet a gadfly even in the urban «jungle». But the risk increases dozens of times for those who go on nature. Experienced travelers know what a cunning gadfly (insect). How to deal with it and at least to protect yourself, they are also aware. Here is what every tourist should take care of:
- about tents equipped with mosquito nets,
- about clothes of neutral color — gadfly adore bright colors,
- about wormwood, tansy, yarrow, which you can carry around and put around the tent,
- about the chamomile, the twigs of which can be thrown into the fire — such flavored smoke will scare away gadflies.
And it is very important to remember: a gadfly — an insect (the photo of which can be seen in this article) is quite dangerous! Neglecting preventive measures is not worth it. And if it was possible to become a victim of the aggressor, then you should take the bite very carefully. Who knows? In this case, the old Russian proverb: “God protects you,” will be most welcome.
What kind of insect is a gadfly and how does it look
Another name for the gadfly is paut, as these flies used to be called in the northern regions. The more common name is the string, and the origin of all these words still remains a mystery to lexicographers.
Gadflies belong to the order of Diptera and infra-order of round-seam flies. Their closest relatives are meat and real flies. To date, about 150 species of gadflies have been described by entomologists, all of them are typical synanthropes, i.e., their habitats are closely related to human life.
Gadflies are distributed throughout the globe, they are not only in Antarctica. The inhabitants of temperate latitudes outwardly resemble an ordinary fly, but slightly larger. The size of an adult gadfly is about 17-20 mm. The insect has a fleecy abdomen and translucent veined wings.
A distinctive feature is the large eyes, but in the horsefly, with which the gadfly is often confused, the eyes are even larger, and it is larger. The differences between insects are clearly visible in the photo of the gadfly and photo of gadfly.
Gadfly with a sucker on the nose, there is no such sucker for gadflies.
Painted gadfly of the northern regions in low-key tones: there are dark brown, lead-gray and grayish-blue specimens.
Southern and tropical gadfly species look more medium-sized bumblebees with their orange-striped color.
As objects of food for a cow, horses and people are uninteresting to these flies, adults do not eat at all, but spend stocks accumulated in the larvae stage. But the biology of parasites is such that they can develop normally only within certain types of animals.
One type of gadfly.
The gadfly larva has an elongated drop-shaped form and an amazing ability to soften the upper layers of the epidermis, thereby deftly penetrating under the skin, causing itching and anxiety in the victim.
Here the migration paths of various species of larvae diverge. Some move parallel to arteries and nerves to the vertebrae, from where they penetrate into adipose tissue and are fixed in the gray matter of the spinal canal.
No less terrifying is the journey of another group of species: the larvae of the gadfly — the esophagus, as the name implies, reach the submucosal layer of the esophagus, where they live and develop.
In its first way, the faces of the gadfly are sent very small, from 1.5 to 2.6 mm long. Having fixed themselves in the place of dislocation with thorns and hooks, they intensively feed on blood and mucus, increasing to 17 mm. Now the spiracles begin to develop in the larvae, and oxygen is required. They go to the area of the back of their master, where they gnaw through the characteristic openings — the fistulas through which they breathe.
Around the fistula and the larvae itself gradually grows a capsule of connective tissue. In it, insects continue to mature to the pupal stage.
It is worth noting that not all the larvae pupate. Some eggs are lost by animals, some of the larvae die during migration, others are suffocating in the nicks. It is believed that about 20% of the gadfly larvae live to the pupal stage, but given the fecundity of the females, they are quite enough to maintain the population size.
Fully matured larva falls from the fistula to the ground, it usually occurs in the morning. Depending on the weather, pupation lasts from 1 to 7 days. Being a circular fly, the gadfly pupa remains in the larval exoskeleton, which serves as an additional protection for it.
In the pupal stage, the insect lasts from 34 to 44 days, after which, within seconds, it breaks the protective sheath along the seam and a gadfly flies out into the light, ready for mating.
The duration of the stay of an insect in one phase or another is not fully understood. The full development cycle of some species lasts for 1 year.
The types of gadfishes known to science are combined into 3 large groups — families:
- Gasterophilidae: gastric ovods or esophaguses,
- Hypodermatidae: hypodermic gadflies,
- Oestridae: nasopharyngeal or cavitary gadfly.
Each family includes several genera and many species. Among them are endemic, for example, human skin gadfly, but most of the species are considered mass, widespread parasites of various animal species and consider each group of species in more detail.
Forced owners of these parasites are most often horses and donkeys. Females approach their victims with care, small flights, and without disturbing the animals, they calmly make a long laying of 5–20 eggs per hair.
Female horse gadfly.
The larvae that have come into the world enter the host’s body on their own or with food. A heavily infected animal suffers first from pruritus, and as a result of the vital activity of the larvae from inflammatory diseases of the internal organs.
The larvae of the esophagus do not need oxygen. They grow into a capsule, like a tumor, which firmly holds them in the esophagus until spring. In May, blood-red larvae emerge from the animal with feces. In the most severe cases, in one horse it can parasitize up to a thousand gadfly larvae.
These flies are attacking cattle. They attack aggressively, pursue the herds, emitting specific sounds, which greatly frighten the animals, forcing them to bunch up. Females attach eggs to animal hair one at a time. The larvae parasitize in the subcutaneous tissues, causing numerous ulcerations.
There have been cases when people became the owners of the subcutaneous gadfly with a fatal outcome. During migration through the body, the larvae traveled to the brain tissue, leading to irreversible brain damage.
This is a group of species of viviparous flies, which are preferred by sheep, goats, donkeys and horses as owners. Females of abdominal gadfly do not lay eggs, but give birth to larvae on the fly. The way to attach the offspring is very original: females spray the larvae into the eyes and nostrils of the victims.
The larvae develop on the eyelids, in the cavities of the skull, inside the eyeball, often causing purulent inflammation.
Do residents of the northern regions need to worry if the only gadfly on a person lives in Central America? It is obviously not worth showing carelessness, suddenly there will be no suitable horse in the way of the female, but there are people sunbathing on the beach.
Ways of infection
Gadflies are typical afagi and don’t eat as adults, but not because they don’t want to. Their oral organs are reduced, the imago has no mandibles or proboscis. Accordingly, they have nothing to bite, so the ways of human infection are somewhat different:
- eggs and gadfly larvae carry blood-sucking insects that feed on livestock, and during the bite of another victim, the parasites are in the wound,
- a person can become the owner of a gadfly larva in tactile contact with an infected animal,
- female gully gadflys can splash the larvae in the human eye,
- личинки желудочных оводов попадают в организм с зараженной пищей или с одежды,
- самки отдельных видов овода буквально вкручивают яйца в кожу жертв.
Человек быстро поймет, что стал хозяином паразитарной мухи. Место внедрения личинки выглядит характерно и ощущения говорят сами за себя.
Признаки заражения личинкой овода
When a parasite hits the eye, there is a strong burning sensation, tearing, and conjunctivitis quickly develops. If you do not see a doctor, you can lose sight.
The larvae of the esophagus and the subcutaneous gadfly show their presence with typical symptoms:
- the place of larvae penetration under the skin is red, swollen, in people prone to allergies itching is unbearable,
- after 7-14 days, there remains a cyanotic edema with a foci of suppuration and a small rod in the center,
- the general state of health worsens: the temperature rises, weakness is noted, nausea — the classic signs of intoxication of the body,
- when the larvae enter the sinuses, pain and swelling appear.
The consequences of parasitism can be the most deplorable. The migration routes of the larvae are not fully understood and, if they enter the brain or heart, tissue degradation becomes irreversible.
As a result of the vital activity of subcutaneous, gastric and abdominal larvae, parasitic diseases develop — skin, intestinal, urinary miasmas. The so-called “vagus larval syndrome” causes hypodermatosis — intermittent and disappearing skin seals. And this is not a complete list of health problems that may arise after meeting with a gadfly, so medical help is needed in any case.
Treatment of parasitic infections caused by gadfly
The doctor is an infectious disease doctor who is ridding a person of parasites. To confirm or refute infection by the gadfly larva allows visual inspection and ELISA.
With a positive test, a gastroenterologist, an ENT specialist, an ophthalmologist, and other specialists are connected to the treatment, depending on the localization of the parasites.
The patient is prescribed a course of antibiotics and antiparasitic drugs. Subcutaneous larvae are removed medically or surgically.
The risk of infection with a parasitic fly, widespread everywhere, is exposed to all, but especially those living or staying in places of development of animal husbandry. Therefore, we should not ignore the elementary means of protection.