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 infected 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.
In total, there are about one and a half hundred species of them in nature.
Appearance of the gadfly
Outwardly, it is very similar to a fly, only the length of its wide and large body with a seam located on the back is 2 cm.
The head is hemispherical, well developed. There are bare eyes on it, and in females they are spread slightly wider at the back of the head than in males; There are three simple eyes. In addition, in the hole on the forehead of the gadfly there are antennae.
The hind legs of this insect are slightly longer than the front ones. The wings of the gadfly have very fine transverse wrinkles and veins, the same as those of real flies. The body is covered with short but dense, sometimes brightly colored hairs.
What do gadflies eat?
An insect such as the gadfly does not eat not only blood, but also anything else, so its life cycle lasts only 3–4 days. During this period, the gadfly exists due to the nutrients that were accumulated by its body when it was in the pupal stage.
Reproduction
A female individual is looking for a suitable victim for her future offspring. Livestock is often suitable for these purposes. The female gadfly lays up to 700 eggs in their hair, and the larvae that emerge from them feed on the blood of the animal.
The larvae themselves have neither legs nor heads. Their body consists of 12 segments. The first two are most often very weakly expressed, so there are only 11 segments. Some larvae are equipped with belts with chitinous spines, and sometimes with fleshy processes. Small anterior motor foramina, one pair, are located between the first and second segments. A pair of posterior motor openings, in the form of retractable tubes, are located on the last posterior segment.
Approximately every fifth egg is a full-fledged future gadfly, capable of continuing the actions necessary for its existence, that is, flight and reproduction, within 30 seconds after birth.
Distribution area of gadflies
These insects are found almost everywhere to the globe, only in Russia there are 6 species of them.
Harm to others
Insects of this species cause huge losses for those who deal agriculture. At the time when female gadflies begin laying eggs, cows’ milk yield decreases, as they interfere with the animals’ ability to eat normally. Moreover, the value of the future animal skin, which is damaged by gadfly larvae, will be significantly reduced.
But the gastric botfly lays its eggs on the horse’s fur, causing itching, the animal licks them off, and they get into its stomach. There they undergo a certain stage of development - molting. After this, they fall onto the soil along with feces and pupate there. For horses, the presence of such “neighbors” of parasites can result in intestinal disease.
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 cycle they 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.
Class - Insects - Insecta, Hexapoda
Department - Insects with complete metamorphosis- Holometabola
Squad - Diptera or flies and mosquitoes- Diptera
Family - Subcutaneous gadflies - Hypodermatidae
Morphology.
Imago.Large insects: pregnant female length 13-15 mm, male - 11-13 mm, resembling appearance bumblebee Their body consists of a head, chest and abdomen, covered with thick hair of yellow, orange and black colors. There are 4 weakly contoured hairless lines on the back. The wings are smoky, span 9-11 mm. The oral apparatus is not developed, they do not feed (Sharova I.Kh., 2002).
Sexual dimorphism. In females the distance between the eyes is greater than in males.
Egg. Oval shape, size 0.8-0.29mm, light yellow color. At one pole of the egg there is a conical appendix.
Larva. The first stage larvae begin to emerge from the eggs laid by the female after 4 days. They are thin, cylindrical, mobile, with an average size of 0.6 mm, slightly whitish. The body of stage I larvae is composed of 12 segments, which are equipped with spines. Stage II larvae are also segmented. The length of the larvae is 18 -20 mm. The first segment carries the reinforcement of the lips, which are close together and have 2 denticles; these indicators distinguish the string larva from the esophageal larva, whose lips are wide open and lack denticles. The color of the larvae varies from ash-white to yellow. Stage III larvae are 22-28 mm long, and the esophageal larva is 16-26 mm long. The dorsal part of the larva is equipped with small spines. The lips and antennae are atrophied. This larval stage lasts 2 months, subsequently the larva falls onto the soil and turns into a pupa, and after 20 - 40 days adult insects emerge from the pupae.
Development.
Phenology of development. The transformation is complete
larvae in the spinal canal of some and in the esophagus of others is 5-6 months (Abuladze K.I., 1990). After this period, the larvae migrate to the back and lumbar region. For further development they need oxygen atmospheric air, for which the larvae form fistulous openings in the skin.
Summary data on subcutaneous gadflies
| № | Indicator name | Line | Esophagus |
| 1 | Wingspan | 9-11mm. | 8-9mm. |
| 2 | Length: females | 13-15mm. | 12-13mm. |
| 3 | male | 11-13mm. | 10-11mm. |
| 4 | Egg | 0.8-0.29mm. | 0.8-0.2mm. |
| 5 | Optimal temperature for larval development | 30-32°С | 30-32°С |
| 6 | Size: Larva I stage | 0.6mm. | 0.6mm. |
| 7 | Stage II larvae | 18-20mm. | 15-17mm. |
| 8 | Stage III larvae | 28mm. | 16-26mm. |
| 9 | Number of spines around spiracles | 20-30pcs. | 10-15pcs. |
| 10 | Transformation of stage III larvae at 29°C | 2-7days | 2-7days |
| 11 | At lower temperatures | More than 70 days | More than 70 days |
| 12 | Emergence of the imago from the pupa | 20-40 days | 20-40days |
| 13 | Female mating time | In 30-80 days. | In 30-80 days. |
| 14 | Lifespan of a gadfly under optimal conditions | 3-10 days | 3-10 days |
| 15 | At low temperatures | Up to 28 days | Up to 28 days |
| 16 | Number of eggs laid per season | From 200 to 800 | From 200 to 800 |
| 17 | Number of eggs per 1 hair | 1 egg per hair | 6-20 eggs |
| 18 | Formation of larvae in the egg | 3-7 days | 3-6 days |
After 8 days, the larvae molt and enter the second stage, which will last 1.5-2 months and end with the transition to the third stage. Mature larvae fall out onto the soil through sinus tracts and pupate. After 20-40 days it emerges from the pupa adult insect and the development cycle repeats.
Geographical distribution.
The distribution area of these pests is very wide, depending on the presence of cattle in the region. Covers the territories of Europe, Asia, Canada, Russia, the Caucasus, England, Japan, Africa, China (Cosoroaba J., 2000).
Maliciousness.
Firstly, a person may become a victim of subcutaneous gadflies. The migration of larvae in the human body ends with their penetration into the head. The most dangerous migration is into the eye. In this case, surgery is necessary, which leads to partial loss of vision. Bodfly larvae cause great harm to animals when migrating throughout the body, destroying blood vessels and causing bleeding, damaging nerves and causing paralysis. Adult gadflies disturb animals during the oviposition period.
Economic threshold of harmfulness. Even 10-15 third-stage larvae that fall out to pupate are dangerous, causing damage to 40% of the livestock.
Struggle.
It is necessary to systematically combat gadflies, taking into account their development cycle (Lukin E.I., 1989). To destroy the larvae of the first stage, animals are treated after the end of the summer of gadflies in southern regions Russia - September, October, November, and in the northern regions August-September-October. To achieve 100% effectiveness, treat twice with an interval of 30 days. Organophosphorus drugs are used, including Blotik and Neotsidol. Currently, Ivermectin (Ivomec) is widely used. The main requirement is the processing of all animals.
3. Lukin E.I. Zoology. Publisher: "Agropromizdat", Moscow, 1989. pp. 211-214.
4. Cosoroaga I. Parazitologie veterinara. Edit: “Mirton”, Romania, 2000. R. 529-
5. Bamakila A., Boulard S. Ghypodermose bovine appoce epidemiologice et caracterisation du cycle biologice en l'estabisement d'un plan de prophilaxia dans le nord est algerien. Edit: Reviste Med. Vet., 1993, 144:8-9 et 693-700.
Every person has at least once encountered this large, “biting” and “harmful” fly. But in fact, “biting” and “harmful” are two different flies: most people confuse the gadfly and horsefly.
Science knows more than 150 species of these insects. All species are classified as flies, whose life is connected with human settlement: where a person lives, an insect is always found there. Scientifically it is called - synanthropization.
Insect gadfly
Appearance
The insect is larger in size than a regular fly. The difference from other large dipterous insects is that its head is movable, semicircular. Connects to the body with a thin stem.
The eyes are bare; in females they are more spread out at the back of the head than in males. The insect has five eyes in total, one pair of large and complex eyes and 3 small simple eyes. Small, short and bristly antennae are located, as if in a dimple, on the forehead.
Adults do not feed, therefore they have no mouthparts. The body of the insect is large, wide, and has a transverse seam on the back. There are short bristles on the body, and the hairy gadfly is also found; it is often confused with a bumblebee. The insect has six legs, with the back pair being much longer. There are two wings, which is why they are classified as dipterous insects. On wings, like regular flies, there are small transverse veins.
The color of an insect depends on its species. Some have an indeterminate color and blend in 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 eggs are formed, the female lays them depending on the species, but most often it is the animal’s food or its fur. Interestingly, when the female of some insect species is just about to lay a clutch, she makes a characteristic sound that the animals hear and begin to worry. The duration of this period depends on the weather and climate; naturally, in the north this period is shorter.
- Larva 1st stage. The larva inside the egg matures 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 into the host’s body begins, how this happens is still not known for certain. Some believe that the larva penetrates the skin by boring through it. Most believe that through natural openings, and in the body they already migrate through the vessels, getting into the adipose tissue. Scientists do not know exactly how long this stage lasts; some believe that it lasts up to a year. What is known is that the larva increases tenfold: from 1.5 mm to 1.5 cm.
- Larva of the 2nd stage. At this phase, the larva gradually moves to the back area, 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 in the skin of the animal, the so-called fistulas. At the end of phase 2, the larvae molt.
- Larva of the 3rd stage. Here the larva gets out through the fistula to the surface and falls on the ground, where it transforms into a pupa. Typically this happens in warm time day - morning or afternoon.
- doll. The transformation into a pupa does not occur instantly, but over several days, sometimes weeks. But the development of the insect inside the pupa takes from one to one and a half months. The pupa itself is almost motionless in this phase.
- Imago. The further transformation of the pupa into an imago (adult) occurs almost at lightning speed (2-3 seconds), and within a minute the insect can fly and mate. Since adult there are no mouthparts, the gadfly is not looking for food, that’s all nutrients were accumulated during previous larval phases. It follows that the lifespan of an adult gadfly is short - no more than three weeks (in non-flying rainy weather up to a month). Moreover, by the end of the phase, the gadfly loses a third of its weight. Interesting fact researchers discovered: males and males fly to the same place every year, where mating occurs.
Gadfly families
Human gadfly
It is worth mentioning separately human gadfly. Fortunately, it is not found in our latitudes, but is found in South America, although it is easily transported 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, etc.), and then with the bite of this insect, the larva gets under the human skin, where all 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 strong natural amber), so it is very sensitive to it, it follows that maintaining hygiene, especially in the hot months, is simply necessary for prevention. Unlike natural odors, the odors of various special sprays repel them, as do some natural aromas, for example, birch tar. It has been noticed that the gadfly cannot stand the smell of Vishnevsky’s ointment.
You can notice the dangerous proximity of a gadfly by observing the behavior of the animal; it becomes restless (runs, twists its head or tail).
If a “bite” occurs, you should immediately consult a doctor. If this is not possible, you can try to deal with the larva yourself. To do this, lubricate the area where the “bite” is found with a fatty and thick substance that does not allow oxygen to pass through (glue, Vaseline or something similar). The gadfly larva needs air, and if there is not enough air, the larva will partially crawl to the surface. And then carefully remove it. The last step will lubricate the damaged skin with a disinfectant.
The described measures also apply to pets.