Mite
Overview
 
Mites, along with tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

s, are small arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

s belonging to the subclass Acari (also known as Acarina) and the class Arachnid
Arachnid
Arachnids are a class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, although in some species the front pair may convert to a sensory function. The term is derived from the Greek words , meaning "spider".Almost all extant arachnids are terrestrial...

a. The scientific discipline devoted to the study of ticks and mites is called acarology.
All members of the subclass Acari are mites, except for the three families of tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

s. Mites are among the most diverse and successful of all the invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

 groups. They have exploited an incredible array of habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...

s, and because of their small size (most are microscopic
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...

) go largely unnoticed.
Encyclopedia
Mites, along with tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

s, are small arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...

s belonging to the subclass Acari (also known as Acarina) and the class Arachnid
Arachnid
Arachnids are a class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, although in some species the front pair may convert to a sensory function. The term is derived from the Greek words , meaning "spider".Almost all extant arachnids are terrestrial...

a. The scientific discipline devoted to the study of ticks and mites is called acarology.

Diversity and systematics

All members of the subclass Acari are mites, except for the three families of tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

s. Mites are among the most diverse and successful of all the invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...

 groups. They have exploited an incredible array of habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...

s, and because of their small size (most are microscopic
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...

) go largely unnoticed. Many live freely in the soil or water, but there are also a large number of species that live as parasites on plants, animals, and some that feed on mold. It is estimated that 48,200 species of mites have been described.

Some of the plant pests include the so-called spider mite
Spider mite
Spider mites are members of the Acari family Tetranychidae, which includes about 1,200 species. They generally live on the under sides of leaves of plants, where they may spin protective silk webs, and they can cause damage by puncturing the plant cells to feed...

s (family Tetranychidae), thread-footed mites (family Tarsonemidae
Tarsonemidae
Tarsonemidae is a family of mites, also called thread-footed mites or white mites.Only a limited number of tarsonemid genera are known to feed on higher plants while most species in this family feed on the thin-walled mycelia of fungi or possibly algal bodies...

), and the gall mites (family Eriophyidae). Among the species that attack animals are members of the sarcoptic mange mites (family Sarcoptidae
Sarcoptidae
Sarcoptidae is a family of mites, of which the most prominent are in the Genus Sarcoptes. Sarcoptic mange is caused by digging mites in that genus....

), which burrow under the skin. Demodex mite
Demodex mite
Demodex is a genus of tiny parasitic mites that live in or near hair follicles of mammals. About 65 species of Demodex are known; they are among the smallest of arthropods. Two species living on humans have been identified: Demodex folliculorum and Demodex brevis, both frequently referred to as...

s (family Demodicidae) are parasites that live in or near the hair follicle
Hair follicle
A hair follicle is a skin organ that produces hair. Hair production occurs in phases, including a growth phase , and cessation phase , and a rest phase . Stem cells are principally responsible for the production of hair....

s of mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s, including humans. Perhaps the best-known mite, though, is the house dust mite
House dust mite
The house dust mite is a cosmopolitan guest in human habitation. Dust mites feed on organic detritus such as flakes of shed human skin and flourish in the stable environment of dwellings. House dust mites are a common cause of asthma and allergic symptoms worldwide...

 (family Pyroglyphidae
Pyroglyphidae
Pyroglyphidae is a family of mites....

).

Insects may also have parasitic mites. Examples are Varroa destructor
Varroa destructor
Varroa destructor is an external parasitic mite that attacks honey bees Apis cerana and Apis mellifera. The disease caused by the mites is called varroatosis....

, which attaches to the body of the honeybee, and Acarapis woodi
Acarapis woodi
Acarapis woodi is a mite that is an internal parasite of honey bees, originally described from the Isle of Wight. Tracheal mites are related to spiders and have eight legs. Acarapis woodi live and reproduce in the tracheae of the bees...

(family Tarsonemidae
Tarsonemidae
Tarsonemidae is a family of mites, also called thread-footed mites or white mites.Only a limited number of tarsonemid genera are known to feed on higher plants while most species in this family feed on the thin-walled mycelia of fungi or possibly algal bodies...

), which lives in the trachea
Invertebrate trachea
The invertebrate trachea refers to the open respiratory system composed of spiracles, tracheae, and tracheoles that terrestrial arthropods have to transport metabolic gases to and from tissues....

e of honey bees. There are hundreds of species of mites associated with other bee species, and most are poorly described and understood. Some are thought to be parasites, while others beneficial symbionts
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...

.

The tropical species Archegozetes longisetosus is one of the strongest animals in the world, relative to its mass (100 μg): It lifts up to 1182 times its own weight, over five times more than would be expected of such a minute animal.

Medical significance

Mites cause several forms of allergic diseases, including hay fever
Hay Fever
Hay Fever is a comic play written by Noël Coward in 1924 and first produced in 1925 with Marie Tempest as the first Judith Bliss. Laura Hope Crews played the role in New York...

, asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...

 and eczema
Eczema
Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...

 and are known to aggravate atopic dermatitis
Atopic dermatitis
Atopic dermatitis is an inflammatory, chronically relapsing, non-contagious and pruritic skin disorder...

. Mites are usually found in warm and humid locations, including beds. It is thought that inhalation of mites during sleep exposes the human body to some antigen
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

s that eventually induce hypersensitivity reaction. Dust mite allergens are thought to be among the heaviest dust allergens.

Like most of the other types of allergy, treatment of mite allergy starts with avoidance. There is a strong body of evidence showing that avoidance should be helpful in patients with atopic dermatitis triggered by exposure to mites. Regular washing of mattresses and blankets with hot water can help in this regard. Antihistamine
Antihistamine
An H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...

s are also useful; Cetirizine
Cetirizine
Cetirizine , a second-generation antihistamine, is a major metabolite of hydroxyzine, and a racemic selective H1 receptor inverse agonist used in the treatment of allergies, hay fever, angioedema, and urticaria.-Availability:...

, for example, is shown to reduce allergic symptoms of patients.

However, not all types of mites are infectious such as Alaskozetes antarcticus
Alaskozetes antarcticus
Alaskozetes antarcticus is a species of non-parasitic mite, known for its ability to survive in subzero temperatures.This animal's name derives from its habitat: Alasko, meaning "from Alaska", and antarcticus, in connection with frigid conditions in which the mite lives...

, an Arctic mite.
They only "Harvest" on Animals. Not Infectious to Humans.

See also

  • Grain itch
    Grain itch
    Grain itch is a cutaneous condition caused by several types of mites, and characterized by intense pruritus....

  • Copra itch
    Copra itch
    Copra itch is a cutaneous condition that occurs on persons handling copra who are subject to Tyrophagus longior mite bites....

  • Gamasoidosis
    Gamasoidosis
    Gamasoidosis is a cutaneous condition that occurs after contact with canaries, pigeons, and poultry, caused by two genera of mites, including Ornithonyssus and Dermanyssus....

  • Chigger bite
    Chigger bite
    Chigger bites are a cutaneous condition caused by trombiculid mites....


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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