AKARIFORMNY MITES (Greek akari — a tick and lat. forma — a look, a form) — the backboneless animals belonging to type of arthropods (Arthropoda), a class of helitserovy (Chelicerata), Acariformes group. It is phylogenetic the ancient group combining apprx. 10 thousand species of the free living and parasitic mites widespread on all globe.
Representatives And. to. usually divide into two suborders: sarkoptiformny (Sarcoptiformes) and trombidiformny (Trombidiformes) mites. In suborders numerous families combine in taxonomic categories (see) various ranks (a superfamily, a cohort, a series, etc.). Soil armor-clad mites — Oribatei (fig., 1), more than 100 families, and an akaridiya (Acaridiae), to 20 families, including granary mites — Acaroidea, or Tyroglyphoidea treat the first suborder (fig., 2 and 3); number of parasitic groups: peryevy — Analgesoidea (fig., 4), wool — Listrophoroidea, itch mites (zudn) — Sarcoptoidea, etc. The second suborder includes up to 60 families. Various pro-stigmatic mites (Prostigmata) concern to him: many land sapro-and zoophages, sea mites — Halacarae (fig., 5), the sucking phytophages — Tetranychoidea (fig., 6), gallic quadruped mites — Tetrapodili which are often allocated in a special cohort, predatory heyletida — Cheyletidae, miobiya — Myobiidae (fig., 7), parasites of vertebrata, iron woundworts — Demodicidae, etc.; representatives of the Parasitengona group are fresh-water mites — Hydraehnellae (fig., 8) and krasnotelka — Trombeae (fig., 9); peculiar sucking zoo - and phytophages — Tarsonemina, napr, a big-bellied tick (fig., 10), etc.
And. to. have the sizes 0,1 — 0,5 mm, it is rare — more than 1 mm. Primitive And. to. are segmented; at the majority of mites the body is divided into front department with oral bodies and two pairs of legs and back — with two pairs of legs, sexual and proctal openings. The actinostome is between oral extremities (helitser and pedipalpa). Helitsera are supplied with the chewing claw; they can be pricking and other form. A skin cuticle thin, quite often there are guards sometimes merged in an armor. Sense bodys are presented by the tactile bristles and skin sensillas perceiving fluctuations, gigro-thermal, chemical and other irritations; eyes simple, many types are blind. And. to. breathe skin and tracheas. Intestines with blind outgrowths. As eliminative organs serve koksalny glands and malpigiyeva vessels of intestines. And. to. razdelnopola; insemination is more often spermatoformny. In a number of groups the parthenogenesis meets (see). And. to. lay eggs, some types viviparous. Postgerminal development is followed by molts and consists of six stages: a prelarva (usually in egg), a larva, three nymphal stages and adult. Adaptive changes of a life cycle A.k. are diverse: development of the rasselitelny and worrying armor-clad stages (adult or nymphal), shortening of a cycle due to reproduction in the nymph flax or larval age (neoteniye), difficult metamorphoses, etc.
And. to. live in various environments: on the land, in sweet waters and in the sea. Among And. to. it is a lot of inhabitants of the soil — consumers of an organic residues, microorganisms and mushrooms, various predators, etc. Many types live on plants, in nests of vertebrata and insects, in foodstuff.
Parasitism, sometimes extremely peculiar is eurysynusic: among And. to. the bloodsuckers, parasites gnawing skin and plumage of birds and hair of mammals, the sucking parasites and galloobrazovatel of plants, etc. meet.
And. to. have medical value. Some tarsonemina cause dermatitis. Scabby zudn cause a mange (see). Many types And. to., living in the dwelling of the person, can be the cause of an allergy (see); granary mites at inhalation and swallowing them with food can cause catarral conditions of respiratory tracts and went. - kish. path. Larvae a krasnotelok the stings cause dermatitis-trombidioz, and also transfer to the person of a rickettsia of the Japanese river fever — tsutsugamush (see).
Economic value A is big. to. So, granary mites are wreckers of grain and grain products (see). Armor-clad ticks are intermediate owners of the tape worms striking domestic and trade animals. Parasitic akaridiya and iron woundworts cause extensive damage to livestock production. Tetranikhovy, gallic mites and tarsonemina damage plants; some of them have phytopathogenic viruses.
Measures of fight with And. to. are diverse and depend on a species of a tick and the nature of the harm done to them (see. Akariaz , Acaricides , Wreckers of grain and grain products, Dermatitis , Mites , Mange ). See also Arachnoid ]].
Bibliography: Determinant of the arthropods damaging health of the person under the editorship of V. N. Beklemishev, page 217, M., 1958.
A. B. Lange.