Gadfly insect. Description, features, types, lifestyle and habitat of the gadfly

Farmers and others who raise livestock are exposed to damage caused by parasitic insects.

Among these pests are horseflies, which not only can injure an animal or a person, but are also carriers of dangerous diseases, since they also feed on dead animals.

Description and features

The two-winged insect with short antennae belongs to the Tachi-nidae family. Large hemispheres of eyes with a multi-colored iridescence on a shaggy body up to 17 mm long, transparent wings of the fly make up the external appearance. The species Dermatobia hominis, which is dangerous to humans, lives in Central America. It is capable of attacking and laying its eggs under the skin.

Many have seen these large flies with bright colors in the countryside, in nature or fishing. Externally, the gadfly in the photo is very similar to the two-winged horsefly; they are often confused with each other. Their habitat is the same. The bite of a horsefly is dictated by hunger; it is a blood-sucking insect. The main difference is nutrition. A gadfly, like a horsefly , can bite, but only for the purpose of reproduction.

In some regions the insect is known as spiderweed. Many species of dipterous flies that parasitize large mammals are collectively called gadflies. Common features for insects:

gadfly dimensions 15-20 mm;
the mouth is absent or reduced;
body with villi;
huge eyes;
oval body;
the front legs are shorter than the hind legs;
almost transparent mesh wings.

The body color is very different. For northern latitudes it is of calmer tones:

brown;
dark gray;
different shades of blue.

In the south and tropics, the insect closely resembles small bumblebees with orange and black stripes. It is believed that the gadfly's flight speed of 120-140 km/h is comparable to that of a dragonfly.

Manifestation of a parasite bite

Consequences of a gadfly bite
If you look at the photo of the symptoms of a gadfly bite in a person, you can note that they are very similar to a wasp sting, namely:

pain;
burning;
edema;
skin redness;
itching;
poor blood clotting;
the bite site on the skin acquires a certain character, a tumor similar to a neoplasm appears.

On a note!
The consequences of a gadfly bite, including an allergic reaction, may go away in a couple of days if the wound does not get infected and purulent inflammation does not develop as a result.

Kinds

The family Nu-podermatidae includes insects in which the larva develops in the nodules under the skin of animals. They parasitize many mammals. Among them:

Small rodents. Here development takes a little time. The female lays eggs on the fur. The larvae that emerge from them burrow under the skin. There is no migration.
Large mammals. After laying on the hair, the larvae that emerge from the eggs begin migrating to the back of the animal. Their path of movement goes along the subcutaneous layer, inside the muscles and internal organs. Travel time is from 3 to 9 months.

There are types of gadflies:

Gasterophilidae – parasites in the stomachs of animals. Flies of medium or large size (9-20 mm). Adults do not need food. They are found in the eastern hemisphere, but equines are common everywhere. The larvae live inside the stomachs of odd-toed ungulates, elephants, and hippopotamuses. The female gadfly lays about 2 thousand eggs on the skin or hair layer near the mouth. Gasterophilus pecorum lays eggs on the grass. The first instar larvae enter the digestive system and live until they grow. They come out naturally (with excrement). Animals infected with parasites develop gastrointestinal pathology.

Horse (Gasterophilus intestinalis) is one of the common species. Length varies from 13 to 16 mm. The hairs on the body are yellow or brown. The wings are all with dark spots. A noticeable feature is a bright black dot in the radial vein. The insect uses horses and donkeys for its reproduction. In females, the ovipositor is strongly bent under the body. During flight, females lay on the surface of the skin in places where victims can scratch with their teeth. When the larva enters the mouth, it develops for about a month, then passes through the pharynx into the stomach. Their number sometimes reaches hundreds.

Northern deer (Oedemagena taran-di) - lives off reindeer. Animals travel great distances to winter. There the insects grow, leave the host and move into the ground. With the onset of spring, deer migrate north. Young gadflies must fly many kilometers to again parasitize animals. Natural instinct drives the insects north, they reach the victims and begin to attack defenseless deer. One female can lay up to 650 eggs.

All gadflies are divided according to the type of mouth opening. In Oestridae typicae it is absent or underdeveloped. Representatives of the small Cuterebridae group have a more pronounced proboscis (mouth), without tentacles. Scientists divide the first type into three sections:

Gastricolae - larvae with two hooks for penetration; there are special tubercles with small spines;
Cavicolae – two hooks and large spines, the female is viviparous, no ovipositor;
Cuticolae - there are no hooks, the spines are small, they are almost invisible.

Cattle attack Hypoderma bovis De G. bovine botfly . For horses and donkeys, the equine species has become a threat. Sheep try to escape from the sheep type Oestrus ovis L. Even wild animals have their own varieties:

American squirrels are attacked by C. emasculator Fitch;
Elephant intestines are infested with Cobboldia elephantis Brau;
rhino suffers from Gastrophilus Rhinocerontis Ow.

In the tropics of Central America lives Ver macaque and moyocuil, which can accidentally attack a person. After a gadfly bites and the larva implants, a large tumor, or hardening, with a hole at the top grows. This type affects dogs and livestock.

The photo shows a gadfly larva

How to avoid meeting a gadfly and how to defeat it

Nothing is impossible in this world, and you can meet a gadfly even in the urban “jungle”. But the risk increases tenfold for those who travel into nature. Experienced travelers know how insidious the gadfly (insect) is. They also know how to fight it and protect themselves at least to a minimum. Here's what every tourist should take care of:

about tents equipped with mosquito nets;
about clothes of neutral colors - gadflies love bright colors;
about wormwood, tansy, yarrow, which you can carry with you and lay around the tent;
about chamomile, the branches of which can be thrown into a fire - such aromatic smoke will scare away gadflies.

And it is very important to remember: the gadfly is an insect (a photo of which can be seen in this article) is quite dangerous! Prevention measures should not be neglected. And if you happen to become a victim of an aggressor, then you should treat the bite very carefully. Who knows?! In this case, the old Russian proverb will come in handy: “God protects those who are careful.”

Lifestyle and habitat

The place of parasitism in gadflies is different, therefore there are 3 types:

Gastric. Distributed almost everywhere. The female lays eggs on wool, limbs or grass. After penetration inside, the maturation cycle begins. The result is access to the surface of the skin through fistulas or with waste products. All this causes severe itching in the animal. The most common is the horse gadfly .
Subcutaneous. The habitat of this type is all latitudes except the Far North. It chooses cattle as its victims. The female insect lays eggs on the fur, and the larva penetrates the skin. A focus of inflammation – myiasis – develops. Before molting begins, the parasite enters the subcutaneous layer, forming holes there. There have been recorded cases of it penetrating inside the skull of an animal and the human brain. This resulted in death.

Subcutaneous gadfly, lays larvae when bitten

Cavity. The main difference from the previous ones is that females give birth to larvae during flight, bypassing the stage of laying eggs. They are able to spray them onto the mucous membranes of the eyes, nostrils of an animal or a person. After which the parasite remains inside the eye, eyelid or nose. Then, by migration, it gets inside - the sinuses, the oral cavity, etc. Severe inflammation develops at the injection site.

The gadfly is most often found on sheep

The human gadfly is not found in Russia, but can be spread by people already infected with parasites. It differs from the others in its penetration mechanism. The female first lays eggs on an insect that can feed on human blood. This is usually a mosquito, tick or other bloodsucker. After a bite, the gadfly larva moves under the skin of the victim, where the life process continues.

The parasite can be found everywhere except the coldest latitudes (Antarctica). mainly lives in warm and temperate climates. In Russia there are many of them in the vastness of Siberia, the Ural and Northern regions. Frequent clusters of insects nearby:

pastures;
livestock farms;
places where animals pass.

Insects love a humid climate, so they swarm in large numbers near rivers, ponds and swamps.

How do horse flies develop?

Female horseflies lay eggs near water bodies on moist leaves. At first the masonry is white, and then acquires a darker color.

After a few weeks, the larvae appear. They can live in different conditions - water is preferred for raincoats, and bullfly larvae live in the soil cover.

To transition to the adult insect stage, the larvae begin to spin a cocoon on land. After 3 weeks, the pupal stage is completed, the insects emerge from the cocoons, dry out their wings, and then are ready to fly.

Nutrition

The parasite larva receives nutrition while inside the victim. Adults cannot absorb food; their oral apparatus is reduced. The pest inside the victim is pear-shaped with the obligatory spines on its scales for advancement. All this is enclosed in a sclerosed capsule, with a hole at the bottom. Length reaches 25 mm, diameter 7 mm.

The basis for nutrition is blood fluid. After securing itself inside the host, the larva begins to accumulate all the useful substances for further existence. The parasite secretes a liquid mass in its body, causing severe pain and inflammation.

Prevention of infection by gadfly larva

Mosquito nets on windows are an effective way to keep parasites out of your home. When going for a walk, it is recommended to treat your clothes with one of the following preparations:

Argus: repellent in spray and spiral form. When treating clothing, the protective effect against gadflies, midges, horse flies and other insects lasts up to 20 days;
“Picnic”: repellent against gadflies and horse flies; when sprayed on the skin, repels insects for 2-3 hours;
OZZ: creams, lotions and aerosols with a wide spectrum of action.

Chemical products are good for one-time use, on a picnic, fishing or on a hike. In your summer cottage against the gadfly, it is better to use traditional methods:

the smell of spruce needles, bird cherry, mint, cloves, basil and tomatoes repels parasitic insects;
the site area is periodically treated with a solution prepared from ammonia, lemon juice and mint mouthwash;
You can spray an infusion of herbs on your clothes: mint, wormwood or tansy.

Maintaining personal hygiene, especially after visiting stud farms and farms, significantly reduces the risk of becoming the host of a parasitic fly larva.

Parasitic and blood-sucking flies:

Tsetse fly: photo.
Photo of horsefly. common pied
photo of bullfly

What is the danger to humans and animals?

The gadfly is a biting insect ; the gastric and cavitary type is considered the most dangerous for people. After entering the body, the larva begins to actively feed. It deprives him of vital energy, vitamins, and pathological processes begin. Migration throughout the body and internal organs, right up to the brain, causes health problems. Deaths from infection are common.

When the larva gets inside the victim, myiasis begins (the formation of a parasite). More often this happens in the summer. The infection process occurs in stages:

a female insect attaches eggs to the scalp of a person (usually the head);
the parasite begins to come to the surface from body heat;
penetration under the skin or into organs;
the formation of fistulas for the breathing of parasites, through which they exit.

There is a certain risk group for a person. This category needs to be careful when walking and interacting with livestock. In an area of increased risk of infection:

advanced age;
insufficient hygiene;
mental illnesses;
craving for alcohol;
diabetes type 1 and 2;
diseases that provoke hematopoietic obstruction;
frequent stays in the tropics and subtropics.

At the slightest sign of infection, you must contact a medical facility. Bodflies are dangerous for animals, they are annoying, and livestock are defenseless from their attacks. The potential victim becomes very nervous and begins to lose weight from poor nutrition.

This reduces milk yield from livestock. Parasitic larvae take useful substances for themselves. A large number of pests weaken animals, they get sick and lose their sight. Migration completes its destructive action after infection. Nerves are damaged, internal bleeding and paralysis begin.

How are both insects similar to hornets?

The hornet is a large insect that is yellow and black in color. This insect looks like a wasp, only different in size. Hornets, gadflies and horseflies are similar in their large size and aggressiveness. They bite painfully. Their bites cause great discomfort and are dangerous.

After bites, the affected area swells, hurts, and itches. For people with allergies, this can be deadly, as the bites can cause anaphylactic shock. Hornets and gadflies settle anywhere - in the forest, in the city, on the plain and in the mountains.

Gadflies and horseflies are dangerous insects that are carriers of serious infectious diseases. Gadflies are parasitic in the body not only of animals, but also of humans. When there is a mass accumulation of insects, it is important to use protective equipment - thick clothing, insecticides. If you have been attacked or even bitten by insects, you should carefully monitor the affected areas and, if you have the slightest complications or doubts, immediately consult a doctor.

Traps for horseflies and gadflies, by what means you can get rid of insects, read more in this article.

Reproduction and lifespan

An insect goes through a full cycle of transformation: egg, larva, pupa, adult. Life expectancy 1 year. There is one peculiarity: adult gadflies do not receive food. Their existence is possible due to the substances in the body obtained by the larva. The life period completely depends on the temperature and the speed with which the insect creates a “platform” for its offspring.

The female gadfly carefully selects a place on the animal's skin. Areas with less wool are suitable for this. They attach up to 2-3 eggs per hair. This condition lasts from 3 to 20 days. Development phases:

The larva at the 1st stage grows for several days, then gets inside the victim, thanks to hooks on both sides. The movement goes through the blood vessels, the spinal column and to the fat layer in the direction of the brain canal. The rest is sent to the esophagus and penetrates into the mucous tissues.
Larvae 2-3 tbsp. move to the back and lumbar region. At the attachment site there are tissue capsules. To develop further, they need oxygen. To receive it, the larvae make special passages through the skin of the animal (fistula). As they develop, they molt and emerge to the surface through ready-made holes in the dermis. After which pupation occurs on the ground.
The next phase lasts from 1 to 7 days after leaving the animal’s body. The rate of further growth of pupae, depending on humidity and temperature, lasts 33-44 days.
As a result, the adult fly (imago) emerges within three to five seconds. The insect is ready for new mating and flight.

The short life cycle of a fly (1 year) ends in death; the gadfly does not hibernate in the fall. During the cold winter, the larvae live inside the victim. An adult insect lives very little (3-20 days). By the end of life it loses most of its body weight. In cold weather, the insect almost does not fly. In this case, life is extended by another month.

Adult gadflies are able to reproduce immediately after emerging from the pupa. It is noticed that the mating process takes place in a constant place where they fly every year. After which the females begin to search for an animal to procreate. A large number of eggs each contributes to rapid reproduction. Insects have few enemies, only birds. In southern regions, gadflies mate longer than in northern latitudes.

Gadflies have adapted to live next to many animals. They parasitize small rodents, artiodactyls, the largest rhinoceroses and elephants. Even with a minimal number, due to the high fertility of females, insects multiply quickly in the almost complete absence of enemies.

Use of pharmaceutical drugs

Medicines to relieve swelling from a bite
It happens that the body has an inadequate response to the action of the gadfly allergen. In this case, you need to relieve swelling from the bite with more effective means:

Suprastin, Tavegil, Claritin will quickly relieve allergies;
a compress of ammonia, soda solution, or any mint toothpaste will cope with itching;
It is worth anointing the bite with an ointment containing corticosteroids (hydrocortisone, Sinaflan, Advantan) so that the wound does not become inflamed;
You can use an ointment for bloodsucker bites based on herbal components or chemical components.

If it is impossible to use the services of a pharmacy, it is recommended to use natural resources, such as:

plantain;
mint;
dandelion in any part of it;
yarrow;
parsley.

You can name many more plants that stop bleeding and have an astringent and anti-inflammatory effect. It is recommended to treat swelling with lemon, onion or garlic, rubbing the inflamed area with a slice.

Symptoms when a parasite is under the skin: what are they?

The gadfly larva can be anywhere in a person. For example, it can be found on the arm, on the chest, on the leg, and even on the head. But their most favorite places to live are the armpits and back. It also happens that the larva of a gadfly in the body is located in the nose or eye.

As a rule, at first a person does not experience any complications or discomfort. In the place where the parasite entered, a small bump appears, reminiscent of a mosquito bite. After a certain amount of time has passed, this area begins to hurt and become inflamed. Afterwards it turns blue or red. Then an abscess forms and opens. Thus, for the gadfly larva, a certain hole is formed under the human skin through which the parasite breathes. As soon as the inflamed area is opened, pus begins to be released from it.

After this, the person’s condition begins to deteriorate sharply. Nausea or vomiting, weakness and dizziness, and muscle pain are the main symptoms of gadfly larvae entering the body. In the area where there is inflammation, the patient may feel something moving.

When these harmful parasites get into the eyes, irritation of the mucous membrane is felt, and eye pressure increases. There is constant lacrimation. In addition, all these signs may be accompanied by pain and bleeding.

The penetration of larvae into the vitreous body of the eyeball is very dangerous. Then the person may lose his sight completely.

When the parasite is in the body, the following symptoms are present:

headache;
deterioration of sense of smell;
swelling of the nose;
pain at the location of the larva.

Surprisingly, these harmful microorganisms can crawl out through the nostril.

Treatment

To exterminate larvae on the surface of the animal, use a 0.25% hexachlorane solution, which is sprayed over the entire body.
The treatment process is repeated at intervals of 10 days, until the end of the flight season for fledged individuals. You can also remove eggs from the hair with a sharp movement of a sharp knife, which must be held at an angle to the hair. Treatment in the mouth is carried out by irrigation with a 2% emulsion of hexachlorane, an oil extract of DDT, turpentine, and diesel oil. One of the selected drugs is used to treat the mucous membrane at a rate of 10-15 ml. One of the effective means for treatment is univerm, which is applied twice orally with an interval of 24 hours. Avermectin, Equisect, Rivertin 1% pastes are widely used. Carbon disulfide is used three times a day, 6 ml, and foals under 3 years old are given 3 ml; this drug is given in winter. The larvae come out with excrement three days after using the drug.

Life cycle

Gadflies are insects with complete metamorphosis. In their development, they go through the phases of egg, larva, pupa and imago. The full development cycle of bovine subcutaneous gadflies ends within a year

The emergence of adult gadflies from pupae occurs very quickly - within 2-3 seconds. and after 30-60 seconds. the fly is able to fly and mate

Adult gadflies do not feed. They live off the nutrients accumulated in the larval phase, so their life is short. An adult gadfly loses up to 36% of its weight by the end of its life. The lifespan of adult gadflies is, according to various sources, from 3 to 20 days. In inclement, cool weather, gadflies do not fly; their energy reserves are consumed slowly, and therefore their life expectancy increases to 28 days. On sunny days, the flight of gadflies is observed at a temperature of 6-8 °C, on cloudy days - at 13-14 °C

Many researchers note that males gather annually in the same places where females fly to mate. After mating, females immediately go in search of animals to lay eggs.

When attacking animals, females of the string and the esophagus behave differently. The line flies near the herd, chasing animals and making characteristic sounds. At the same time, the animals are very worried and try to escape from persecution. The female esophagus approaches animals covertly, using short flights and crawling. Remaining unnoticed, she calmly lays 5-20 eggs in a row on one hair. The female string lays one egg per hair

Female gadflies are very fertile, which allows them, despite their relatively small numbers, to staunchly support the existence of the species. For laying eggs, females prefer areas with short hair and abundant undercoat in the area of the hungry pit, the soft wall of the abdomen, the groin, and the front of the thighs.

The beginning and duration of the flight of gadflies depends on the zonal characteristics of their development, and the flight is longer in the central zone, foothill and mountain zones, and shorter in the lowland zones of the south. It also lasts less in the extreme northern regions of its distribution. Depending on the weather conditions of the year, the flight dates of gadflies may shift by two to three weeks.

Stage I larvae. The formation of larvae inside the egg continues at line 3-7, at the esophagus - 3-6 days. It is believed that the optimal temperature for the development of larvae in the egg is 30-32 °C. Under such conditions, development ends in 3.5 days with the release of 90-100% of the larvae.

The larvae hatching from the eggs penetrate the host's body. Extracts from the midgut of stage I larvae and the esophagus have a strong dermatolytic effect, which allows them to penetrate the skin of animals. The migration routes of larvae in the host’s body have not been precisely determined, but most researchers believe that stage I larvae, after penetrating through the skin into the animal’s body, migrate along large vessels and nerves to the spine and through the intervertebral foramina enter the adipose tissue of the spinal canal, and stage I larvae esophagus migrate towards the esophagus and are localized in its submucosal layer

It should be noted that the infestation of the esophagus and spinal canal by larvae varies according to periods of the year, which is associated with the timing of the flight of gadflies. The total duration of stay of the larvae in the esophagus and spinal canal has not been established, but there they increase in size from 1.5 - 2.6 mm to 17 mm

Larvae of stages II and III. From the esophagus and spinal canal, the larvae migrate to the back and lumbar region, where they form connective tissue capsules. For further development, they need atmospheric oxygen, for which the larvae form fistulous openings in the skin.

After the formation of a fistula, connective tissue capsules are formed around the larvae, in which their further development takes place. The larvae molt and enter the third stage. The natural mortality of stage I larvae with an infection intensity of 100-250 pieces per animal is 70%, the death of stage III larvae in the nodules is 21.5-21.8%

Mature larvae of the third stage emerge from the capsule through fistulous openings in the skin and fall to the ground, where they pupate

Pupa phase. Most stage III larvae emerge to pupate in the morning and afternoon. The fallen larvae are inactive, their pupation occurs within 1-2, less than seven days. The development of pupae in natural conditions with temperature fluctuations during the day within the range of 10-21 ° C and relative humidity of 60-80% lasts 34-44 days.

Studies by many domestic scientists have shown that the subcutaneous gadflies of cattle give only one generation per year, and throughout the entire territory of the joint habitat of the esophagus and the line, all phases of the development of the former are noticeably shifted to earlier dates

Preventive measures

As they say, prevention is the best cure. Therefore, when going for a walk or a trip to nature, you need to take measures to protect yourself and your loved ones.

When going outdoors, you need to pay special attention to the choice of clothing. It should not be of bright colors, so as not to attract undue attention from horse flies.

It is better to give preference to things that cover the body as much as possible, made of dense, but breathable fabrics, of a khaki color. It is not recommended to use perfume in such cases, as it attracts insects.

Various repellents containing 20% diethyltoluolamide in the form of creams, lotions, and sprays will help repel horse flies. You can also use traditional methods:

If you are going to live in a rural area, then you need to collect wormwood and tansy in small bunches. By hanging them outside on the walls of the house at the entrance and windows, a person will scare away horse flies that try to approach the home.
Bouquets of tansy and chamomile in the house would be useful. You can spread tansy stems around the tent if you have to spend the night outdoors. This plant perfectly repels blood-sucking insects.
When making a fire, it is recommended to burn several chamomile flowers and stems in it. Then evening gatherings by the fire will be safer. You can also use valerian, juniper pine, wheatgrass root, and cinnamon.
If you treat the body with a solution of carbolic acid, horseflies will never attack.
To repel blood-sucking insects, an effective remedy is to lubricate exposed areas of the body with fish oil.
You can sprinkle chamomile tincture on your body and clothes. The most effective in this regard are the Persian and Caucasian species of this plant.
If there are puddles nearby, you can pour a little gasoline or diesel fuel into them. Flies that want to get drunk on the fly, having landed in such traps, will no longer fly up.

Sometimes it happens that you have to stop for the night in places where there are concentrations of horse flies, mosquitoes and mosquitoes. Then it is better to follow the safety rules:

you need to set up your camp on a hill, away from the swamps,
sleep under a mosquito net, and if possible, smear your face with mud (silt), especially before going to bed,
It’s better to tuck your trousers into your socks or shoes,
put on all your clothes, especially at night,
be sure to use a protective mask and gloves,
Use repellents applied to clothing; they retain their effect for weeks.

There are many recipes on how to avoid insect attacks, but the main thing is to use them in time and correctly.

The horsefly, being a blood-sucking insect, causes inconvenience to both animals and people in the warm season. Many people are familiar with its obsessive buzzing and painful bites. In hot weather, far from cities, horseflies stage real attacks, interfering with comfortable outdoor recreation or work in the garden. They also annoy livestock. What kind of insect is this and why does it attack?