Are ticks different in humans and animals? What types and varieties of ticks are there?

Photo of ixodid tick

Among the many thousands of species, we can name several when the activity of ticks turns into aggression towards humans and animals: ear tick, argas tick, cat tick, gamas tick, etc. A small animal can cause great damage to health, crops, and sometimes is a direct threat to human life , infecting it with relapsing fever, Lyme disease, encephalitis, tularemia, Q fever, etc.

Struggle for existence

To survive in a world of dangers and harsh realities, you need to reproduce your own kind as often as possible. For ticks, this process directly depends on the environment: how comfortable the conditions are and the availability of sufficient food. Ticks are of different sexes. Animals mate, depending on the species, on a warm-blooded host, others - in external environment. As a rule, a male that has fertilized several females dies. To begin laying eggs, the female ixodid tick must gain strength: feed on blood for a whole week. When full, it lays eggs: at one time their number can range from one to 5 thousand. From larva to adult goes through several stages. The larva turns into a nymph only after the first stage of molting. At this stage, sexual characteristics are not yet expressed. Only after the last molt does the transformation into an adult occur. The full cycle of evolution from larvae to adult cannot be unambiguously determined by how ticks reproduce.

The “inner world” of ticks

The digestive tract is capable of processing semi-liquid, liquid food. This explains the sucking appearance of the pharynx. Special glands produce saliva, which has an anesthetic effect: a person or animal may not immediately feel the bite. Ticks breathe with their lungs and have tracheas (they have the shape of holes on the sides of the body). The circulatory “motor” is a heart with cavities or, in other species, there is no circulatory system at all. Blood feeding for arachnids of both sexes is necessary for reproduction.

How long a tick lives is impossible to answer unequivocally, because... the full period of its development can vary from a year to several years. Blood-sucking animals, having drunk blood, accumulate energy, maintain viability for a long time in unfavorable conditions for themselves, even starve until they find “prey” again.

By the way, adult females, preparing to lay eggs, suck 100 times more blood than their own weight. This explains that the male leaves the bite victim before the “girlfriend”. The waiting period can last up to 10 years. The tick is hardy, so it can live a long time.

Habitat

The places where ticks are found are the most unpredictable. These are desert sands, water, grass litter, plants, calorific animals, humans. Comfortable conditions is created not only by nature (global warming, warm or hot weather, humidity), but also by humans. Cutting down conifers and planting in this area deciduous trees- a fertile environment for reproduction. This is what all the invasions are connected with. more ixodid bloodsuckers. Traces of ticks are found throughout the forest-steppe and forest zones of Russia, in public gardens and city parks.

Argas mite

The main time of a tick's life is waiting. It settles on a branch, in a mattress, folds of linen, etc. Seeing a “target”, it tries to fall and cling to the body with its paws, which react to the heat and smell of the body. This is the answer to the question, do ticks fly? No, they swoop or crawl towards a potential food source. In nature, a tick larva cannot rise higher than 0.3 m above the ground, and an adult bloodsucker overcomes only 1.5 m.

The period of tick activity ranges from May (although the first bites were recorded in April) to the end of June. At this time, the ground temperature is more than +7 degrees, the sun's rays are warm, and there is sufficient humidity. Then there is a slight decline, after which in August-September, in areas where ticks live, there is a surge in bites, especially on animals. Demotion outside temperature air below 5°C is a signal to stop activity, entering a state of stupor.

For your information. IN Lately Due to global warming, these time boundaries have expanded. Today, even in November, cases of tick bites are recorded.

The natural environment and ecology are changing on the planet and by no means better side. TO external changes Ticks also adapt. They easily adapt to them, demonstrating an example of survivability and adaptability to survive in the harshest conditions.

Ticks are animals from the class of arachnids. Today, more than 54 thousand species of these arthropods have already been found and described. Of the total, only 144 species have become extinct. The rest are still alive today. This is the largest group of the arachnids. Small ticks and a fairly wide food spectrum helped ticks “conquer the world.”

Principles of classification

There are different types of ticks. Some feed on plant sap, others on rotting organic matter, others on blood, and others on dead parts of the epidermis and fur. But there are no highly specialized species among them. If it's sap, it's the sap of many plants. If blood, then from all warm-blooded organisms living in the area. If organic, then it is still of plant or animal origin. The classification of ticks is multi-stage. These animals are divided into groups not only by lifestyle, but also by type of nutrition and appearance.

On a note!

These arthropods are not insects, but are closer to animals such as spiders, crabs and crayfish.

What types of ticks are there?

The classification of living organisms in biology is based on phylogeny - the evolutionary origin and development of species. But there is still debate among scientists about the phylogeny of ticks, and the data may change in the future.

On a note!

The superorder Parasitiformes includes:

• The order Opilioacarida, which includes only one family of harvest mites. The family contains 25 modern species.
• The order Ixodida includes one superfamily of ixodoid ticks, which is divided into 3 families: , argasidae, Nuttalliellidae - endemic to Africa, having a single species in the family.
• The order Holothyrida contains 27 species, but all of them are found in southern regions planets and feed on the hemolymph of dead arthropods.
• The order Mesostigmata is the most numerous in the superorder, comprising more than 70 families containing a total of 8,000 species of mites. Representatives of this order are predators.

On a note!

Of interest to humans are the order Ixodidae and Mesostigamata. The former are dangerous to life, the latter are useful as assistants in the fight against agricultural pests.

There are more than 30 thousand species in this superorder of arachnids. The classification of acariform mites is quite confusing and is carried out using different methods. Of interest in this superorder are the sarcoptoid mites, which cause ear scabies.

Brief description and names of tick species

All 54 thousand can only be described by a reference book on acarins, so we will have to limit ourselves to the most common and those living within the reach of residents of the Russian Federation.

Ixodidae

This group of ticks is ubiquitous in Russia. The three most common species received the collective name “forest” for their predilection for forest biotopes. All species prefer deciduous and mixed forests. The most common of them are:

• canine;
• (Dermacentor reticulatus);
• genus Haemaphysalis.

A tick with a pattern on its back is a meadow tick (Dermacentor reticulatus). It is not found in forests without undergrowth. This tick waits for its victim in the grass, which is why it is often called the grass tick. Prefers open spaces: edges, water meadows, pastures. Can tolerate flooding by melt water. Very cold resistant. Its activity begins earlier than that of the taiga. Peak activity occurs in April-May. It ceases its activity only with the onset of cold weather.

His closest relatives from the same family are found:

• (Dermacentor marginatus) in the steppes and forest-steppes of Kazakhstan, the European part of the Russian Federation, Transcaucasia, Central Asia, in the south Western Siberia;
• – Siberian forests;
• Dermacentor silvarum – forest-steppe of Eastern Siberia and the Far East.

All of these species have a characteristic pattern on their back, which can be seen in the photo of the meadow tick below.

Taiga, in addition to the “honorary” title, is also called “wood mite”. It does not sit in trees, waiting for prey, but few people wonder where this animal came from on clothes. Many believe that it jumped from a tree branch. Moreover, this species prefers forests rather than open spaces.

The ixodid family Haemaphysalis has similar habits. But ticks of this family prefer deciduous forests, where they wait for their prey, sitting on the grass. They live in Crimea, on Far East and Transcaucasia. They can be found in the south of Altai, Western Siberia and Transbaikalia.

Ixodids have similar not only appearance, but also lifestyle. A sexually mature female tick feeds only once, preferring large mammals. The drunk female falls away from the victim to complete. Ticks of the ixodid family lay up to 17 thousand eggs. Only a few survive to sexual maturity due to large quantity and difficulties in finding the victim. The female lays eggs on wet soil. The hatched larva finds a victim and, having drunk blood, disappears to transform into a nymph. The actions of the nymph are exactly the same.

Natural enemies

Ixodidae feed on:

• birds;
• small reptiles;
• predatory insects;
• other predatory mites;
• ants.

Destruction of the habitat of these creatures leads to an increase in the number of ticks.

Argaceae

This family includes the largest representatives of the superorder of mites. The size can be from 3 to 30 mm. The total number of species in the family is 200. 12 species can attack humans, causing a severe allergic reaction. Argasaceae also carry 2 types of relapsing fever and tick-borne borreliosis. Dangerous for humans:

• Persian;
• Caucasian;
• village;
• shell

Europe and Russia have been familiar with the last three for a long time. Persian – the new kind ticks imported from the Middle East. In endemic areas it suffers fever, which is very severe in foreigners.

In appearance and behavior it is very similar to, but larger. Body length up to 10 cm, width up to 5 mm. The main object of attack is birds. Also attacks people and is capable of jumping onto people from the ceiling. Active at night.

On a note!

Ticks do not build nests, but the female Persian tick lays 30-100 eggs in cracks on the walls. Such a clutch can be equated to a nest, especially during mass reproduction of arthropods.

And scabies (Sarcoptes scabiei), which affects humans. Animal and human sarcoptiform ticks do not overlap. That is, you cannot get scabies from a dog.

The external characteristics of mites of the order Sarcoptiformes are so similar that there is debate in scientific circles whether they should be considered one species or several. But these small arthropods have different food sources. Photo of the human mite that causes scabies is below.

But not all arthropods are equally harmful. There are also harmless and even necessary ones.

Saprophytes

These are arthropods that feed on decaying organic matter. Saprophytic mites are relatively harmless. Most of them process rotting organic matter, improving soil quality like earthworms. But the “dust allergy” known to many actually occurs due to the presence of Dermatophagoides farinae in the home.

These are microscopic creatures measuring 0.1-0.5 mm. They feed on epidermal scales, particles of fallen hair and animal fur, and waste products.

“Dust allergy” is actually caused not by house dust, but by the excrement of dust mites and particles of the shells of dead arthropods. Dermatophagoides farinae live in uncollected dust in corners and under furniture, in sofas, pillows, and mattresses. For regular thorough cleaning and treatment upholstered furniture.

A microscopic insect - a tick - often causes panic in people. A small bug can make them paranoid, constantly inspecting their own skin and the thick fur of their pet. How dangerous ticks are and what diseases they cause, we’ll find out right now.

Appearance

How do ticks attack?

Why is tick saliva dangerous?

1. The effect of anesthesia so that a person or animal does not show concern and does not interfere with the insect doing its dirty deed.
2. Suppressing the immune system so that it does not provoke tick rejection.
3. Destruction of tissue and vessel walls, allowing blood to flow freely through the trunk.

The most dangerous diseases

What viruses does this little bug carry? First of all, the infection affects the infected person nervous system: various kinds of neurological disorders appear, which ultimately can even lead to death. The incubation period lasts about two weeks, after which the patient feels weak and tired, his body temperature rises, accompanied by muscle pain and headaches. After five days the symptoms disappear, but after a week they come back with a vengeance. In addition, irreversible changes occur in the brain. The patient needs immediate medical attention.

Are ticks dangerous for dogs? Undoubtedly. Like humans, animals can contract another terrible infection - borreliosis. In this case, not only the nervous system is affected, but also the cardiovascular system. At first, the disease, the incubation period of which lasts a month, resembles ARVI. If therapy is started in time, it can be cured with antibiotics. Otherwise, the person will remain disabled. As for dogs, they will also suffer from severe joint damage, remaining lame and crippled for the rest of their lives.

Another dangerous infection is hemorrhagic fever. It affects all internal organs of a person. At first, the disease resembles ordinary poisoning, but already in its second stage complications may arise: toxic shock, renal failure and even cerebral coma. Recovery is long and takes several months. Therefore, if you doubt whether ticks are dangerous, think about the serious consequences that their bite causes.

Diseases in dogs

In addition to borreliosis, our beloved pets are also threatened by other troubles. For example, bartonellosis is a bacterial infection of red blood cells, macrophages and endothelial cells. Symptoms include fever, drowsiness, weight loss, inflammation of the eyelids and joints, weakness of the hind limbs, and anemia. Although sometimes the disease can be completely latent: owners are sincerely surprised when their seemingly healthy dog ​​suddenly dies. If the virus is not treated, it causes complications such as bleeding and meningitis.

The so-called blood diseases also include ehrlichiosis, against the background of which the dog loses weight, has constant hemorrhages, and shortness of breath. If the disease is not treated, it leads to severe damage to all organs.

Are ticks dangerous for cats?

Our favorite furry creatures are also not immune to serious diseases carried by insects. The most famous among them is hemobartonellosis. Its main symptoms are loss of appetite and complete apathy. In some cases, anemia is observed, which is accompanied by weight loss, rapid heartbeat, and pallor. Some housewives notice that the cat begins to eat dirt or garbage. Without timely assistance, the animal may die from complications caused by anemia.

Now you understand how dangerous ticks are to humans and animals. In most cases, they cause serious health problems that lead to either disability or death. Even timely treatment does not guarantee the absence of complications - chronic dysfunction of internal organs, systems, joints. When visiting your doctor, find out about the correct therapy. Strictly follow all instructions, including daily routine and balanced nutrition.

How to get a tick?

How dangerous are ticks to humans? Because they are carriers of deadly viruses. To avoid getting sick, prevention is necessary: ​​constant examination of the skin after visiting the forest, choosing closed clothing during walks in nature. If, despite all the tricks, the tick manages to attach itself to the body, it must be removed as quickly as possible. There are three effective ways.

True quantity various types ticks discovered and described by zoologists are thousands of times greater than the number known to the average inhabitant of the planet. If you ask any person to name the types of ticks known to him, then, most likely, he will remember only 2-3 names, in best case scenario- up to 5, and, rather, will name not specific species, but certain groups, varieties, corresponding to certain characteristics.

For example, almost all residents of Eurasia are well aware of ixodid ticks - the very ones among which there are carriers of tick-borne encephalitis, fatal dangerous disease. Many people also know about scabies (and not only those who themselves suffered from scabies), and gardeners and flower growers are well aware of spider mites. These species, as well as dust mites and red mites, perhaps represent the entire “set” known to the general public.

For example, the photo below shows the well-known dog tick, the main carrier of tick-borne encephalitis in the European part of Russia:

And this creature with a difficult-to-describe body shape is an itch itch (photo taken using a microscope):

Today, science has described more than 54 thousand species of mites, and their number is constantly increasing due to the discovery of new representatives of this group of arthropods, many of which are microscopically small in size. Scientists estimate that there are about a million different species of ticks on Earth, and they have yet to be named.

On a note

In terms of species diversity, mites surpass even the order of spiders - the latter number just over 42 thousand species.

Compared to the number of living species of ticks studied, not many fossil forms have been described - about 150. This is partly due to the fact that the remains of ticks that lived in previous eras are difficult to find and identify. In addition, there is a hypothesis that this group of arthropods is currently experiencing its heyday - living conditions on modern Earth are optimal for ticks, and this contributes to active speciation in many of their genera and families.

However, in reality, most ticks are completely harmless to people and animals. The most extensive groups in terms of the number of species are saprophagous mites that live in the soil and feed on decaying debris dead plants and animals. These creatures are extremely useful for biocenoses, and not only do not harm, but also bring great benefits to natural ecosystems and agriculture.

On a note

Mites (Acari) are grouped into a large subclass of the Arachnida class. It is interesting that the spiders themselves form an order in this class, and among mites, scientists have identified several different orders, and therefore a subclass had to be formed to unite them.

The diversity of mites is exceptional even for the phylum arthropods. Among them there are both microscopically small forms, distinguishable only under a microscope, and animals with a body size of up to 10 mm (especially after saturation). They have very varied colors, various shapes bodies and very effective and bizarre adaptations for their lifestyle. No wonder that general characteristics this subclass is not so easy to give.

The photo below shows the Argas mite:

Ticks live in a wide variety of biotopes - from dry steppes to tropical forests, from earthen litter to carpets in apartments. There are even known species that live under water. They inhabit the upper layers of the soil in huge numbers, where sometimes hundreds of individuals are found in 1 cm3 of soil.

A significant problem is the classification of all this diversity of species. As a rule, they are divided into groups according to anatomy, various physiological characteristics and lifestyle. Groups of the same order (taxa) are included in higher associations, as a result, orders and families are formed, each of which is characterized by certain characteristics of their representatives.

This division is very arbitrary. The taxonomy of the subclass is constantly being revised, and many experts offer their own options for dividing the group into subgroups. In particular, it is popular to distinguish harvest mites as a superorder for their very specific structure.

The photo below shows the harvest mite (Opilioacarus segmentatus):

This superorder is notable for the fact that it includes the most famous ticks among the people - the ixodid ticks, the same ones that urban residents of central Eurasia are terrified of because individual representatives of some of their species can be infected with the tick-borne encephalitis virus and, when bitten, can infect a person with it. . Since this disease is deadly, intensive care is required after infection, but reliable prevention of the disease is quite difficult.

Another interesting feature of this group is its very low representation in paleontological remains. The reason for this “gap” in the evolutionary record is not fully understood, but it is precisely this that makes it difficult to trace the developmental path of this group of mites. Some soil gamasid mites are considered to be the closest to the original forms, and the most highly developed are various predatory forms of the same group. Although it is not entirely correct to speak unequivocally about the evolutionary superiority of one group over another.

On a note

It is incorrect to talk about saprophytic mites. Saprophytes include only microorganisms - bacteria or single-celled fungi. Mites that feed on decaying organic matter are called saprophages. It is also incorrect to call mites saprotrophs - the fundamental difference between saprotrophs and saprophages is that saprotrophs do not leave behind solid waste products (excrement) after feeding, while saprophages do.

A remarkable group in this superorder is the uropod mites, which mainly inhabit the soil. Among them are:

This is interesting

The most epidemiologically significant species are:

Tick-borne encephalitis is carried by several other types of ticks: Ixodes pavlovskyi, Haemaphysalis concinna, Dermatocentor marginatus and others. There are only 14 species, outwardly quite similar to each other, and in some cases it is extremely difficult to identify them (especially when it comes to immature individuals). For this reason, the common name has stuck among the people - “ Tick-borne Encephalitis", which sometimes also applies to those species of ixodids that do not carry the virus, but look similar to the true carriers.

On a note

Notable among them, for example, are the myrmecophilous mites Antennophoridae, which live in anthills, attach to the lower part of the ants' heads and feed on food debris remaining on the ants' jaws. The photo below shows a corresponding example:

Gamasid saprophagous mites in huge numbers inhabit the corpses of animals and insects, excrement, and other organic remains. It is noteworthy that these species settle on various carrion insects. For example, if you lightly tap a dried crust of manure with a stick, simulating the touch of a fly or rat, hundreds of macrochelys or califora mites instantly appear on the surface of the crust, ready to grab onto the insect and then “fly” with it to a new food substrate.

The photo shows a scarab beetle covered in mites:

The tracing name of this group from Latin is thyroglyphoid mites. The group received its Russian-language name because its representatives very often settle and reproduce in huge quantities in storage facilities for agricultural products. Here different types They feed on grain, husks, molds, and animal products.

This is interesting

The most notable among barn mites are the following:

• Flour mite, damaging flour, starch, bran, various grain processing products;
  
• Cheese mite, which is often found in long-stored cheeses;
• Sugar mite, which damages sugar and the raw materials for its production;
  
• Wine mite that settles on the surface of wine if the container with it is not hermetically sealed;
• Bulb mite, a pest of onion, potato, garlic, and beet stocks.
  

All of them lead to damage and deterioration in the quality of stored products.

Itching

This is interesting

The passages of scabies can sometimes be seen under the skin with the naked eye - they look like a mesh of lines.

The larvae emerging from the eggs feed on the epidermis in the maternal passages for some time, turn into nymphs, crawl to the surface of the skin, where the males turn into adults and mate with immature females. After this, the females bite into the skin and begin to make their own passages.

The vital activity of scabies causes severe itching in a person - the disease itself is called scabies. Likewise, mange can occur in cats, dogs, rats and many other animals.

Zheleznitsy

Ironweeds are very specific mites. At a minimum, in appearance they are very different from other ticks, since they have an elongated back part of the body, similar to a tail. Moreover, their length together with such a “tail” is no more than 0.3-0.4 mm.

These mites are most interesting because they constantly live on the human body. Of these, the two most common types are:

1. Demodex folliculorum - lives most of the time in hair follicles;
2. Demodex brevis - inhabits the sebaceous glands, the secretion of which is excreted into the hair follicles.

Both species feed on gland secretions and normally do not harm humans. However, when they multiply profusely, they can cause demodicosis - a dermatological disease in which the skin peels off, foci of inflammation develop and itching occurs.

According to research, these ticks are widespread - almost 100% of the planet's population is infected with them. And precisely due to the fact that infestation by them practically does not manifest itself in any way, most people do not even know about such infection, just as they do not know about the existence of the ironworts themselves.

The so-called dust mites (Dermatophagoides sp.)

This group includes several species of very small mites that have adapted to living in human housing and feeding on exfoliating skin particles present in household dust.

It is known that each person loses approximately 1.5 g of dry dead epidermis per day - this is what these creatures consume as food. Moreover, this amount of “food” is quite enough for the existence of an entire population indoors.

This is interesting

Today, the ability of dust mites to feed, including mold fungi, has been discovered.

Due to their microscopic size, dust mites can settle inside mattresses and in the upholstery of upholstered furniture, from where it is almost impossible to expel them. They inhabit carpets, crevices behind baseboards, and dust in the corners of rooms in large quantities, and therefore fighting them in most cases is a difficult task.

The photo below shows a Dermatophagoides pteronyssinus dust mite in a carpet:

At the same time, dust mites can cause severe allergies. It is believed that most cases of asthma develop in response to constant inhalation of air that contains dust from the excrement and chitinous coverings of these creatures. Excrement contains specific digestive proteins that cause sensitization in humans.

Types of spider mites that harm agriculture

Perhaps, of all the mites that are pests Agriculture, arachnids are the most famous.

Firstly, they are diverse and there are more than 1200 known species. Secondly, they are very versatile in nutrition. The type species of this family, the common spider mite, is distributed throughout the world and affects at least about 200 plant species. Moreover, these 200 species are only those that are known to scientists. Perhaps the diet of this tick is even more diverse. It is capable of hitting most garden crops grown in middle lane Russia, but most of all it affects cucumbers, tomatoes, eggplants, bell pepper and strawberries.

Its relatives are less versatile, but no less harmful. Garden, hawthorn, citrus and other mites of this group are considered a real disaster in gardens and vegetable gardens.

Finally, spider mites cause serious damage to plants, significantly reducing the yield of fields and gardens. In addition, mites infect flowers and trees in natural habitats.

On a note

This group of pests got its name because, when infecting plants, mites entangle their habitat with a thick web, in which, as if in a shelter, they feed and reproduce.

It is not surprising that spider mites are actively being fought, and the most effective and rational way to destroy them is to involve other mites in this...

Enemies of spider mites - phytoseiulus

Phytoseiulus is the largest family of gamasid mites. There are more than 2,000 species, the vast majority of which are voracious predators that destroy many small invertebrates.

In this group, Phytoseiulus persimilis has the greatest economic importance, which is used in biological control with spider mites. One adult of this predator eats up to 20 adults per day spider mites, their eggs and larvae, and the more intensely it feeds, the more eggs it lays and the more equally voracious larvae and nymphs are then born.

On a note

Phytoseiulus feed not only on spider mites, but also thrips, nematodes and some other harmful invertebrates. Therefore, their use in biological control is considered an integrated method of plant protection.

Today in Europe there are already nurseries for growing phytoseiulus, which are sold in batches to greenhouses and garden farms. Here they are released onto plants, and within a few weeks their numbers grow rapidly due to a decrease in the number of spider mites. This is possible without insecticides and other chemicals protect the harvest.

Red mites and other predatory species

Perhaps every person has seen these ticks. They are found in large numbers in spring and early summer under stones in the forest or in vegetable gardens, where they move smoothly, as if “swimming” along the ground in search of their victims - small insects and other mites.

In Japan and on the islands Pacific Ocean These ticks carry the causative agent of tsutsugamushi fever.

Representatives of this group are of economic importance because they can cause serious diseases in poultry.

Normally, these mites are commensals and do not lead to severe consequences for birds. They settle in feather stumps and feed on their walls. Each feather forms its own colony, from which mites can move to neighboring feathers.

Wild birds usually carry out some hygienic procedures to help control the number of these mites, and a significant part of these “hosts” die during molting. However, when birds are kept in cramped enclosures, mites multiply here in huge numbers, cause itching, inflammation, and breaking off feathers, which is why the birds do not gain the required weight and even die.

Oribatid ticks as carriers of helminth infections

Oribatids are generally considered useful pliers, involved in the formation of soils. Millions of them can live in one cubic decimeter of forest soil - they constantly eat the remains of plants and animals and turn them into a substrate assimilated by plants.

The ability of oribatids to spread helminth eggs is important. Thus, some species of this group of mites eat the eggs of tapeworms of the Anoplocephalata family, after which the larvae hatch from the eggs in their bodies, and then the mites themselves and the plants are eaten by large cattle. Already in the digestive tract of the animal, the ticks die, and the helminth larvae are released and burrow into the intestinal epithelium, causing monieziosis. This disease leads to a slowdown in the growth of young cows, sheep, goats, a decrease in milk yield and sometimes even to the death of animals.

The photo shows a winged tick of the family Galumnidae, a carrier of helminth infections in cattle:

In conclusion, we note that even the main groups of mites are difficult to examine even briefly. However, the above information is already enough to roughly imagine the diversity and huge number of varieties of ticks, as well as their significance for ecosystems and human life.

External structure diagram

Life cycle

Reproduction of some varieties occurs before the onset of the imaginal phase, that is, at the tritonymph stage. The average tick lives quite a short time. Many individuals live only a few weeks.

Ixodid ticks are the longest-lived of these animals and can live up to several years.

When exposed to unfavorable conditions, some species may enter a state of diapause. This is a condition in which metabolic processes in the body are slowed down and are used to survive unfavorable conditions.

Species diversity and features

As noted above, the types of ticks are extremely diverse. Let's look at some groups of these animals that are most important for humans and their economic activities. Mites include agricultural pests. These species are carriers of the most dangerous diseases for humans spread by these organisms - tick-borne encephalitis and. Experts who study ixodid ticks (sometimes incorrectly called “ixoid ticks”) state that they are the most significant for human health. These types of ticks are carriers of the most dangerous diseases for humans spread by these organisms - tick-borne encephalitis and (Lyme disease). The genus Ixodes includes more than 240 species. It is this genus of ticks that is most significant for human health. In Russia, the most carriers are dangerous diseases There are two representatives of this genus: the taiga tick (Ixodes persulcatus) and the dog tick (Ixodes ricinus).

The taiga tick predominates in the Asian part of Russia, as well as in some European regions of our country. In the European part of Russia, the canine species dominates. The forest species is another variant of the name for the dog tick. The most common disease (for the northern hemisphere) transmitted by these organisms is borreliosis. It is caused by spirochetes that enter the human bloodstream when bitten by an infected tick. At the very beginning, this disease manifests itself:

• aching muscles
• chills
• headache
• general weakness

The defeat gradually increases various systems organism, even to the point of death. Unlike Lyme disease, tick-borne encephalitis is dangerous viral disease, caused by a neurotropic, RNA-containing pathogen. This disease is characterized by seasonality due to life cycle ixodid ticks. In the Far East of Russia, a subtype of this disease is common, characterized by a more severe course and increased mortality. Similar to Lyme disease, encephalitis is initially characterized by fever, malaise, muscle pain, and headache. Dog and taiga ticks are the main carriers of encephalitis in Russia. The bite of a taiga tick infected with the pathogen is dangerous for humans due to the fact that it transmits a dangerous infection to the affected host. The bite is also dangerous for people because, in addition to encephalitis, it can spread borreliosis.

In some cases, some types of insects are confused with mites. For example, lice are not mites, they are insects. Also classified as insects is the moose louse (otherwise known as the moose tick). In fact, this is not a louse or tick, but blood-sucking flies called deer bloodsucker (Lipoptena cervi). That is, the so-called moose ticks belong to the class of insects, not arachnids.

Subcutaneous view (demodex) under a microscope

Argas species

The rat mite is a representative of the Gamasaceae. It, like the mouse, attacks rodents, birds and people. When bitten by infected rat mites, itching and dermatitis develop. This species is also dangerous because it can even infect with plague and rat typhus.

However, it causes significant harm, affecting crops and indoor plants.

Practical significance and danger

Let’s summarize, which ticks are dangerous for humans, what dangers do they pose, and why is a certain species dangerous for humans? It is believed that out of everything species diversity Ixodidae are the most dangerous to humans. Statistics on tick bites show that not all ixodids are carriers infectious diseases. Many individuals do not carry pathogens of infectious diseases, and their bite is fraught with only painful sensations. How dangerous ticks are to humans depends on what diseases they carry. Their number in a certain region and the level of their infection with the pathogen directly reflect the degree of risk to the population.

Among the widespread diseases transmitted by these animals, encephalitis and borreliosis are the most dangerous, and it is these that people who spend time in nature should be wary of.

Scabies is a much less dangerous, but very unpleasant disease and a fairly common disease. Dust mites, invisible to our eyes, are permanent inhabitants of homes and can cause unnoticed harm to the health of the respiratory and immune system person. Certainly, modern science Not everyone knows everything about these animals, and further research is required on this important group of species.