Ticks belong to the class of arachnids: general characteristics of parasites, description and types of representatives

A tick is an insect or arachnid

Despite the fact that outwardly the tick resembles an insect, this species has nothing to do with them. Ticks belong to the arachnid order, so it is more correct to call them animals.

The practical importance of ticks in nature and what danger ticks carry

At the mention of these animals, many have an association with blood-sucking parasites that carry dangerous diseases.

In fact, certain types of ticks (most often ixodid) pose a serious danger to humans and animals, however, predatory arthropods are also of great importance to the environment.

In addition, some representatives of the tick order are not predators and eat plant foods. The main significance of ticks for nature and man:

1. Participation in soil-forming processes: in the decomposition and humanization of organic residues, increase friability, play the role of orderlies, eating parasitic microorganisms and spreading beneficial ones;
2. Purification of the plant from spores of epiphytic and parasitic fungi;
3. In the foci of endemic vector-borne diseases, arthropods become a leveling factor, play the role of natural vaccinators;
4. Predatory species of mites are used in agriculture for pest control.

However, when assessing the importance of ticks for humans, the scales are outweighed by their negative impact. The danger posed by pests:

• carry pathogens of various human and animal diseases: encephalitis, borreliosis, scabies, tularemia, etc.
• their waste products can cause a severe allergic reaction;
• spoil food (grain, flour, dairy products, etc.);
• destroy cultivated plants, feeding on their juices.

Who are ticks

Ticks are a separate subclass of arthropods. Moreover, this subclass is considered the most numerous. They are found on all continents, live in the soil, organic residues, inhabit the nests of birds and animals, water bodies, parasitize on the body of humans and animals.

What class do ticks belong to?

As mentioned above, mites belong to the class of arachnids.

What does a normal tick look like?

Like all members of the class, ticks lack wings. In adults, there are 4 pairs of legs, in nymphs and larvae there are only 3.

The shade of the animal can be different depending on the species: transparent, gray, yellow or dark brown.

The body, as a rule, has a flat oval shape, covered with a protective chitinous shell. In most species, there are no eyes, it is oriented in space with the help of special sensory organs.

What does a female tick look like?

Females are larger than males, their body is covered to a lesser extent by a chitinous cover - the shield is located behind the proboscis and occupies about a third of the body surface, the rest is soft and elastic. On the dorsal surface of the base of the proboscis there are paired pore fields that perform the function of sensory organs.

What size tick

The body length of arachnids can range from 80 microns to 13 mm, having fed, the individual increases in size up to 30 mm.

The structure of the body of the tick

The integuments of the body are heterogeneous: partly hard, and in some places very elastic. Due to this, the pest is able to significantly stretch during feeding.

Life cycle of mites

Most representatives of the species lay eggs, but there are also viviparous mites. The life cycle of arthropods includes the following stages:

• egg;
• larva;
• nymph;
• imago (adult).

With the establishment of a comfortable air temperature (+15-20 degrees), arachnids begin to multiply actively. Before this, the female needs to get enough blood. After feeding and mating, the female lays eggs. Their number may vary, depending on the type of tick.

Females of some species are capable of laying several thousand eggs.

The duration of the embryonic stage also differs depending on the species - from 5 to 14 days. After that, larvae are born, which differ slightly from adults in appearance.

The larvae of some types of ticks begin to look for a prey already at this stage of development, while others do not need food. After molting, the animal moves to the next stage of development - the nymph. During this period, the tick must take food, after which another molt occurs and the individual passes to the imago stage.

Social Structure and Reproduction

As mentioned above, acarids begin to multiply actively with the advent of heat. For this, the female must be full. Mating can take place on the host, grass, leaves, and so on.

In some cases, fertilization can take place without the participation of a male, in which case only female larvae will appear, and if a male participated, both male and female.

The male does not choose the female in any particular way; the individual who is at that moment at a closer distance becomes a partner. The males of most species die after reproduction.

Features of character and lifestyle

Arachnids begin to show their first activity in the season when the soil warms up to 3-5 degrees. In Russia, most often this period occurs in late March and early April. The peak of activity falls on May-August. Further, it gradually decreases and when the temperature is set below the specified ticks fall into hibernation.

The population and density of parasites directly depends on weather conditions. So, if the summer was cool, with a lot of precipitation, and the winter was snowy and not cold, the next year the population will increase significantly.

Due to this, the bite of the parasite is not felt by a person. The duration of blood sucking can be up to 15 minutes. The lifespan of a tick depends on the species. For example, dust mites live 65-80 days, while forest mites can live up to 4 years.

Under adverse conditions, arachnids fall into a state of suspended animation - all processes in the body slow down and the animal falls into a kind of hibernation.

After awakening, the tick can continue its life activity without any consequences for its body.

What does a tick eat

According to the method of nutrition, arachnids are divided into 2 groups:

• predators;
• saprophages.

Saprophages feed on organic matter. Most of the saprophages are recognized as beneficial to humanity, as they play a significant role in soil formation. However, there are saprophages that use plant juices as food, including useful crops.

Such animals are considered parasites, as they can cause significant damage to agriculture and horticulture, destroying the entire crop in a short time.

There are also saprophages that feed on particles of exfoliated human skin, hair and natural human secretions. This group includes dust (household) mites.

They do not attack a person, do not bite and do not carry infections, but they can harm his health by causing a strong allergic reaction. Saprophages also include barn mites, which eat grain, flour, dried fruits, and others, making food unsuitable for human consumption.

Predatory mites attack warm-blooded mammals, including humans, birds, and amphibians. In some cases, they attack their relatives - herbivorous ticks. The pest clings to the victim with the help of its legs and then purposefully moves towards the bite site.

Tick ​​Habitat

Natural enemies of the tick

Arthropods are one of the last positions in the food chain, so many species use them as food.

Enemies in nature for them are:

• spiders;
• frogs;
• lizards;
• birds;
• This;
• dragonflies.

Ticks classification

In total, about 50 thousand species of these arachnids are known. Most of them parasitize on humans, animals and plants. The following is a classification of species depending on the type of host.

Ticks that parasitize animals

Representatives of the Argasidae and Ixodes families parasitize on animals. Pests attack an animal, feed on its blood, infect with viruses, cause allergic reactions and a general weakening of the body. These include the following types:

Ticks that parasitize humans

The following types of danger to humans are:

Ticks parasitic on plants

Harm to ornamental and horticultural plants is caused by representatives of the acariform order, among which mites from the superfamily Tetranych mites cause the greatest harm to plants. Such parasites include the following types of ticks:

• cobweb;
• flat;
• gallic.

General characteristics of ticks of different types

According to the generally accepted classification of these arthropods, it is customary to divide them into 3 superorders: parasitomorphic, acarimorphic, and saprophage. Below is a description of some common types of mites.

How tick infections are transmitted to humans

Diseases transmitted by ticks

Not every individual carries dangerous viruses, but the percentage of those infected is quite high. The most common diseases carried by ticks are described below.

Tick-borne viral encephalitis

An acute infectious disease that affects the brain. It is considered the most common and dangerous disease of all carried by ticks. The causative agent of the infection is an arbovirus, which is transferred to the human body at the time of the bite.

Infection is also possible through the use of raw milk from goats and sheep.

The incubation period lasts 10-14 days, in some cases its duration can be 60 days. As a rule, the disease begins with a sharp rise in temperature to critical values ​​- 39-39,5 degrees. Other symptoms follow:

• chills, fever;
• headache mainly in the occipital region;
• general weakness, lethargy;
• nausea and vomiting;
• muscle weakness;
• numbness of the skin of the face and neck;
• lower back pain.

The prognosis of the disease depends on the general health of the patient, the degree of infection and the form of the course of the disease. The consequences of infection with encephalitis are severe disturbances in the functioning of the central nervous system and cognitive impairment. The most serious complications include:

• cerebral edema;
• coma;
• violation of breathing and motor functions;
• epilepsy;
• cerebral hemorrhage;
• disorders of consciousness.

There is currently no specific treatment for tick-borne encephalitis. Therapy is exclusively symptomatic. With a deep dysfunction, their full recovery is impossible, and the disease often has a fatal outcome. All over the world, the generally accepted method of preventing encephalitis is vaccination.

Tick-borne borreliosis Lyme disease

The causative agent of the disease is the Borrelia bacterium. Its penetration into the body causes severe damage to internal organs: the heart, liver, spleen, eyes and ears. The nervous and lymphatic systems are also affected. Borreliosis occurs in acute or chronic form. Infection is possible through the bite of an ixodid tick or milk.

The incubation period of the disease ranges from 2 to 35 days, after which the following symptoms occur:

• muscle and joint pain;
• headache and dizziness;
• temperature increase;
• weakness, fatigue;
• red round spots on the body.

The last symptom is a specific sign of borreliosis and manifests itself 3-30 days after the bite. At an early stage, the disease is easily treated with antibiotics, with untimely treatment, serious complications of borreliosis may occur:

Tick-borne monocytic ehrlichiosis

The cause of the development of the disease is infection with pathogenic microorganisms - erlichs. Bacteria penetrate the bloodstream and spread in the cardiovascular system, causing the formation of multiple nodular inflammation.

Infection occurs at the cellular level. Foci of inflammation inhibit the work of vital organs: bone marrow, liver, heart.

In the absence of therapy, the disease becomes chronic. A person becomes infected as a result of the bite of an ixodid tick or from domestic animals that have been bitten by the parasite.

Ehrlichiosis symptoms:

• general physical weakness, fatigue;
• increase in body temperature up to 39 degrees;
• chills, fever;
• the appearance of red rashes on the skin;
• nausea, vomiting, diarrhea;
• rapid weight loss.

The first signs of the disease may appear as early as the third day after the bite. In some cases, symptoms may be absent for up to 21 days. Ehrlichiosis therapy is based on the systematic use of antibiotics. As a rule, with proper treatment, complete recovery occurs in 2-3 weeks.

Possible complications of ehrlichiosis:

Granulocytic anaplasmosis

The causative agent of anaplasmosis is the bacterium anaplasma. Penetrating into the blood, it spreads throughout the body, disrupting the work of all organs and systems.

As the disease progresses, the immune system weakens, and multiple foci of inflammation appear.

In nature, the carriers of the bacteria are wild rodents; in the urban environment, mice, dogs, and horses are susceptible to it. However, a person can only become infected through the bite of an ixodid tick. The incubation period is from 3 days to 3 weeks. After its completion, a person experiences the following symptoms:

• fever, chills;
• general state of intoxication;
• migraine;
• nausea and vomiting, abdominal pain;
• pain in the right hypochondrium;
• dry cough, sore throat;
• lowering blood pressure.

Most often, the disease is mild and has a favorable prognosis. Anaplasmosis is treated with antibiotic therapy. Complications occur extremely rarely, as a rule, in people with severe chronic diseases.

Tularemia

The cause of tularemia is a rod bacterium. Infection occurs through the bite of an ixodid tick and as a result of eating infected food.

Most of all, the infection affects the lymph nodes, it can also affect the mucous membrane of the eyes, lungs and skin.

The incubation period is most often 3-7 days, but can last up to 21 days. Clinical manifestations of tularemia:

• rash on the body;
• fever, fever;
• muscle and headache;
• redness and burning sensation of the cheeks;
• swollen lymph nodes;
• weakness, low blood pressure.

Treatment of tularemia is carried out only in a hospital. Therapy involves dezontikation measures, surgical opening of suppuration, taking antibacterial drugs. Consequences of the disease:

• infectious-toxic shock;
• disorders of the cardiovascular system;
• meningitis;
• secondary pneumonia;
• arthritis.

A person who has been ill with tularemia develops a strong immunity to the pathogen bacteria.

Procedure for detecting a tick on the body

If a parasite is found on the body, it must be removed immediately. It is recommended to contact a medical institution for this. If there is no first-aid post nearby, you need to remove the tick yourself:

• prepare any container with a tight lid for a remote tick and an antiseptic for treating a wound;
• wear rubber gloves or otherwise protect the skin;
• take a special tool to remove the parasite or ordinary tweezers;
• capture the tick as close to the bite as possible;
• with scrolling movements, gently remove the bloodsucker without jerking and place it in a container;
• disinfect the wound.

The tick must be sent to a special laboratory for analysis to determine whether it is a carrier of dangerous infections. If the result is positive, you should consult a doctor to prescribe preventive measures. Within 3 weeks, you should carefully monitor your well-being and, if alarming symptoms occur, immediately inform your doctor about it.

preventive measures

When hiking in nature, it is necessary to observe conditions that prevent the penetration of ticks on the skin:

• the use of special repellent preparations to repel parasites;
• tuck outerwear into pants, and pants into socks and boots;
• use headgear and hood;
• give preference to clothes of light colors - bloodsuckers are more noticeable on it;
• do not walk on narrow paths with tall grass;
• conduct inspections every 2 hours;
• upon returning home, take a shower and wash clothes.