Today we will talk about gadflies. Let's try to put all the dots on this question - what kind of insect is it and how it can harm our health. Perhaps our reader already knows something, or maybe he will discover something new.
Life and death of a gadfly
First of all, gadflies are one of the families of dipterous insects, which also include flies and bees. For this reason, gadflies look like their cousins and lead a very similar lifestyle. Today, entomology includes approximately 150 species of various gadflies, but the predominant number of them are more harmful to warm-blooded animals than to humans. Of all this diversity, only one species, which is called the human skin gadfly, attacks us. The habitat of this insect is Central America, therefore, as always, residents of temperate zones of Russia are the luckiest.
This may be news to some, but adult gadflies do not bite. Moreover, they do not even eat throughout their entire lives, which is not so short for those on hunger strike. How then do they live? The fact is that they use very economically nutrients, accumulated during the larval and pupal stages. Insects lead an active life exclusively in warm sunny weather when it is not worth spending energy on increasing metabolism during low temperatures and resist the wind in flight. On average, the lifespan of a gadfly, of all its types, ranges from 3 to 5 weeks. However, under favorable circumstances, the insect can live for a month and a half.
If gadflies do not bite and rarely lead an active lifestyle, why did they annoy people so much that they deserve a whole article? It's all about their larvae, which not only bite, but are also able to penetrate the skin of animals and humans, depending on the species, and cause significant harm the health of its owner.
Let's take a closer look at the most interesting facts about their life as gadflies.
The female cutaneous or bovine gadfly lays eggs in certain places on the hairline or directly on the skin of large ruminants in places with the thinnest and most delicate skin. Such places are skin folds in the groin or armpit area, on the skin of the udder, and so on. After the larvae hatch from the egg, they pierce the skin with their powerful jaws, while feeding, and thus move under the skin towards the upper surface of the animal's back. By this time, the larvae have time to mature, emerge to the surface of the skin, pupate and fall to the ground.
The gastric botfly strives to lay its eggs where they will be swallowed by the animal - the edges of the lips, the mirror of the nose. Perhaps this type of gadfly is the most intelligent. Females are able to lay offspring even in areas that are relative, for example, places on the skin where the animal reaches with its teeth to scratch itself, as well as on the grass of pastures. In the latter case, the eggs will simply be swallowed. They will continue their development in the rumen of ruminants, and then in the form of a pupa they will emerge through the esophagus, pharynx and nasal passages.
Human gadfly in the conditions of our continent it can only develop in laboratory conditions. In our country, neither the air temperature, nor the length of the daylight period, nor the duration of summer are suitable for him. But in the conditions of Central America he is very comfortable. The attack on people occurs quietly and imperceptibly, the female gadfly lays eggs on the scalp, and the larvae, gnawing through the skin, move closer to the bones of the skull.
In all cases, all types of gadflies cause significant harm agriculture, especially in the field of dairy production. When the active year of gadflies begins, cows' milk yields decrease by an average of 15%, and weight gain - by 30-35%.
With timely treatment of livestock against gadflies, it is possible to avoid the penetration of larvae under the skin, however, the very presence of these insects greatly irritates the animals, as a result of which productivity is greatly reduced.
Gadflies prefer almost all types of large and small ruminant and whole-hoofed animals - large and small cattle, pigs, horses. However, there are species that preferentially attack only a certain type of animal, for example, the deer botfly.
The cattle senses the string, which is what the female gadfly is called, from a long distance. Apparently because the insect is capable of producing a characteristic buzzing sound. As soon as one cow from the herd hears the line, she emits a warning moo, the animals gather in groups, stop feeding and drinking water, and behave quite belligerently. If there is a pond nearby, the cows will definitely climb into it up to their horns, leaving only their nostrils on the surface to breathe.
Female gadflies are also not born with bast. Knowing how cattle react to them, they can fly up, landing at long distances and in short dashes bring them closer to their target.
Gadflies are characterized by such a phenomenon as a male harem, if one could put it that way. In the area, most often in dry lowlands, groups of males gather, waiting for a female to appear. The lines are like honey, they fly into such harems one by one, mate and fly away to lay eggs.
If you look into the linguistic origin of the word “gadfly,” scientists have not been able to figure out its meaning. The concept of “pout”, widespread in the Siberian outback, refers specifically to the gadfly, but has nothing to do with the blood-sucking horsefly, which is very similar to the gadfly.
Stages of larval development
- subcutaneous;
- cutaneous;
- abdominal (sheep);
- gastric (horse).
Subcutaneous
Cutaneous
Cavitary
Gastric
Why is the gadfly dangerous for humans?
How does infection occur?
The gadfly larva does not affect everyone. People who are at risk should be especially careful in nature and when interacting with pets. What factors need to be considered:
- old age;
- poor hygienic conditions;
- mental illness;
- alcoholism;
- diabetes;
- vascular diseases causing obstruction in the bloodstream;
- travel to tropical and subtropical regions.
Gadfly larva in a person - symptoms
- the formation of a boil on the body;
- tumor;
- nasal congestion;
- a feeling that something is moving under the skin;
- fever;
- swelling of the face;
- diarrhea;
- vomit;
- redness of the eyes;
- anemia.
A large number of larvae inside the body and their migration can lead to negative consequences. The human gadfly contributes to the emergence serious illnesses, such as:
- allergy;
- secondary purulent infection;
- pneumocephalus (presence of air in the skull);
- meningitis;
- stomach ulcer;
- erosion of the nose, face, eyes.
Removing gadfly larvae
- Local anesthesia is prescribed.
- Using a scalpel, the doctor makes an incision to enlarge the wound.
- The surgeon then removes the larvae.
- After surgery, the patient is given a course of antibiotics to prevent infection.
- The wound heals within one to two weeks.
- In some cases, small scars may remain on the body.
Video
The first type is dangerous for both humans and animals. If treatment is not timely, disastrous consequences can occur.
The second type is characteristic of He, of course, is not dangerous like the first type, but still, if this happens, boils form on the body of a person or animal. In addition, there appear severe pain. Pus may then be released.
The cavity type is most common in goats. The larvae are first found in the nostril, and then penetrate the respiratory tract.
The adult gadfly larva is a fly. Its size is about 2 cm. It is somewhat similar to a bumblebee.
But to distinguish it from this insect, there are a number of signs:
- big head;
- large eyes;
- blue belly;
- orange paws;
- transparent wings.
Already half a minute after emerging, an adult gadfly can fly. A female individual produces about 600 eggs. But, fortunately, only 1/6 survive.
There are about 7 species of larvae in our country. They mainly live in the body of cattle. There are known cases where gadfly larvae were found in the human body in Russia. Their favorite place to be is the eyes or skin.
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.
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.
The penetration of larvae into the vitreous body of the eyeball is very dangerous. Then the person may lose his sight completely.
- 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.
How is diagnosis made?
The main method is to take a blood test. It determines the amount of antibodies. The patient is also asked a number of questions. For example, they ask whether he has been to places where the disease is common. In addition to all this, the specialist conducts a visual inspection. Using this method, you can detect an inflamed purulent abscess. It has a hole through which air flows. The doctor examines the area using special device, namely magnifying glasses.
If you are absolutely sure that there are gadfly larvae in the body, then you should not contact a therapist, but immediately an infectious disease specialist.
How is treatment carried out when infested with larvae?
Removing gadfly larvae: how does it happen?
A complex operation should only be performed 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 this entire procedure, it is possible that 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 bandage is applied to the place where the abscess was previously.
Prevention of infection
But most often the gadfly larva penetrates the human skin in countries with a tropical climate. And if you decide to go there, then follow a few simple rules. Places where it lives should be avoided large number insects Of course, you need to wear clothing that will protect you from bites. There is a huge selection in stores now good repellents. These should also be used.
If, for example, an insect bites you, you should not panic ahead of time, but you should not forget about it either. First, you should treat the wound disinfectant. And watch her. If something goes wrong, you must immediately contact a specialist. The doctor will examine you, if the diagnosis is confirmed, he will send you for the appropriate procedures, and if the opposite is true, you can safely return home. And don’t forget that vigilance never hurt anyone.
Medium size. Gadflies belong to one of the numerous families of these dipterans whose larvae are parasites. In nature, there are approximately 150 species of these insects. Humans are attacked by one species of these insects, Dermatobia hominis, which is found in the regions of Central America.
Species
Cycles of life
The gadfly is an insect that has the following life cycle: the egg turns into a larva, which becomes a pupa and the end is an imago (adult). The entire development cycle of an insect lasts a year. The transformation of the pupa into an adult occurs almost instantly, two to three seconds, and within the next minute, the individual can already fly and is ready to mate.
Living off the resources accumulated in the larval phase, adult individuals do not need food; according to various estimates, their life expectancy is from three days to three weeks and by the end of their life life cycle lose 1/3 of their body weight. In cloudy or cool weather, the gadfly's flight period stops - in such cases, the insect, preserving its energy, can live up to 28 days.
In cloudy weather, the gadfly flies at 13–14 degrees; on sunny days, the insect flies at 6–8 degrees. The age of insects is associated with the characteristics of their zonal habitat and directly depends on weather conditions. Researchers believe that insects mate in the same place every year. At the end of the fertilization process, females begin searching for animals in order to lay eggs. The formation of larvae in the egg occurs depending on temperature regime, and can last from three days to a week.
Stages of larval development
Having hatched, the larvae of the first stage of development begin to penetrate the body of their host. It is assumed that at this stage, penetrating the body through skin, the larva of the line continues to move along the nerves and vessels, goes to the spinal column and penetrates the tissue of its canal. The larva of the esophagus moves towards the esophagus, where it is localized in its body.
The period of stay of the larvae in the places where this stage is located is not precisely determined, but their size increases from one and a half millimeters to one and a half centimeters. At stage II, the larvae continue their migratory activities. Having moved to the back and lumbar region, having formed connecting capsules, the larvae, which require oxygen, form fistulas.
Human skin gadfly (Dermatobia hominis)
Gadfly happens:
Horse Gadfly(Gasterophilus intestinalis) belongs to the most common species; its length is 13-16 mm.
The color is yellow-brown, the chest is covered with protruding yellow or brownish hairs, the hairs on the abdomen are straw-yellow with an admixture of black. The wings are covered with small dark spots, and on the radial R1 vein, at the point where the remaining R veins branch off, there is a bright black dot. Females have a long ovipositor that bends under the abdomen, and males have trochanters of the hind legs with a process.
Gadfly-hook (larva)
Gasterophilus intestinalis (larva) (photo from www.diptera.info)
Ready to pupate, they come out along with the droppings and complete their metamorphosis on the ground. Sometimes the first stage larvae penetrate under the skin of a person and, moving in it, cause a “creeping disease” (poricozha). But they cannot fully develop on humans and soon die.
Their growth rate depends on temperature environment and on the condition of the animal itself.
Worldwide distribution. Found anywhere there are horses or donkeys.
Life cycle
Gadflies lay eggs in the host's body or sometimes spread them in another way, for example, with an ordinary housefly.
The eggs are laid directly into the animal's skin, where the larvae hatch from the eggs: high temperature the animal's body causes the eggs to mature after contact with the body. Some species of botflies also live in the digestive tract, as skin irritation caused by the larva causes the animal to lick the area, whereby the larva enters the mouth and is swallowed.
Myiases can be caused by the penetration of a larva into the skin (or folds of skin) on a host animal.
Mature larvae fall out of the host and complete the stage of transformation into a pupa already on the ground.
Gadflies constantly cause difficulties in equestrian sports for people caring for horses, since gadflies lay eggs on inside the legs of horses, on the tibia, on the knees, and sometimes on the throat or nose, depending on the type of gadfly. These eggs, like small, yellow blobs, should be removed promptly during the insect breeding season (late summer and early fall) to avoid infecting the horse. When a horse rubs its nose against its legs, the eggs fall into the mouth, and from there into the intestines, where the larva grows and moves into the skin. When the larvae mature, the horse develops a tumor the size of a fingernail. thumb hands, the swelling is not painful, but if it appears in the place where the saddle or bridle is put on, the horse will be unable to work until the wound caused by the appearance of young gadflies heals. In addition, the larva moving to the surface of the skin can cause sores in the mouth, abdominal ulcers and blockage of the intestinal (anal) opening, leading to colic.
Removing eggs(which cling to the owner's hair) is complicated by the fact that the bone and tendons are located directly under the skin on the tibia: the eggs must be removed with a sharp knife (or blade) or coarse sandpaper. In addition, eggs must be detected in a timely manner before they are ripe. During their maturation, there is a possibility of human infection.
Prevention against larvae can be carried out by spraying with several types of drugs, including dichlorvos, ivermectin and chlorophos.
Scientific classification
Kingdom: Animals
Type: Arthropods
Class: Insects
Squad: Diptera
Suborder: Short mustache
Infrasquad: Muscomorpha
Superfamily: Gadflies
Family: Gadfly (Gasterophilidae)