From Big Medical Encyclopedia

ARGASOVY MITES — the backboneless animals belonging to type of arthropods (Arthropoda), a class of helitserovy (Chelicerata), Parasitiformes group, a superfamily of Ixodoidea, the Argasidae family; specific carriers of the activator of a tick-borne typhinia.

Argasovy mites (full size of 2 — 13 mm): 1 — Ornithodoros papillipes; 2 — Argas persicus; 3 — Alveonasus lahorensis.

The family combines apprx. 100 types; it is subdivided into two subfamilies — Argasinae Can. and Ornithodorinae P. - Schtr.; they include five childbirth: Argas, Alveonasus, Ornithodorus (fig., 1 — 3), Otobius, Antricola. In the USSR 17 types belonging to the first three labor meet. The northern border of their distribution passes 50 °C across the line. highway. Further others on the North mites of the sort Argas come. Number of types And. to. from the North increases by the South.

A shape of a body — uploshchenno-oval, at saturation beaded. Length is 2 — 13 mm. Coloring gray or light brown. The body is covered with a soft leathery cuticle with numerous grooves and folds. Most of representatives of family is deprived of eyes. The body consists of a gnathasoma (a complex of oral parts) and an idiosome (actually bodies). The idiosome bears 4 pairs of legs which all joints are mobile, except for the 1st, grown together with a body. Eliminative organs — malpigiyeva vessels and koksalny glands. Breath is carried out by means of tracheal system. Sexual dimorphism is expressed poorly.

And. to. live in holes, nests, caves, under canopies of rocks (the gnezdovonorovy trapping parasites). Their active movement is limited. Eat on various wild and domestic animals. In total And. to. — obligate bloodsuckers. Process of suction is painless. Duration of a krovososaniye is various — of several minutes till 1 — 2 o'clock. The weight of a full female is 6 — 12 times more of the weight of hungry. Once the female lays 50 — 200 eggs, repeated layings occur after a new krovososaniye. U A. to. 3 preimaginalny phases: egg, larva, nymph. Egg large, spherical, to dia. 0,5 — 0,8 mm. The larva at the majority of types is active. The nymphal phase consists of several morphological stages (from 2 to 8). And. to. differ in durability and ability to long starvation. E. N. Pavlovsky and A. N. Skrynnik showed that separate individuals can live up to 23 years, without food survive up to 11 years. At optimal conditions a life cycle of development (from egg to egg) lasts from 6 months to 2 years (at different types).

And. to., as it is specified — specific carriers (see) the activator of a tick-borne typhinia (see). Distribution of the natural centers of this disease matches an area And. to. sorts Ornithodoros. The main carriers and keepers of spirochetes in the USSR are O.'s mites of papillipes and O. of verrucosus. These types differ in the greatest aggression in relation to the person. In the natural and antropurgichesky centers (see. A natural ochagovost) spirokhetoz in areas of Central Asia and Kazakhstan a carrier of spirochetes (Borrelia sogdiana) are O.'s mites of papillipes. In Transcaucasia, Stavropol Krai and in Ukraine of spirochetes (Borrelia caucasica) transfer O.'s mites of verrucosus. Smaller value as carriers have O.'s mites of alactagalis, O. of tartakovskyi, O. of nereensis. Infection of the person can occur at a krovososaniye of one individual of a tick. And. to. keep spirochetes in process a metamorphosis and transmit them to the posterity transovarialno (from a female through eggs). The infecting ability remains at a tick for life, without decreasing at starvation and low temperature. And. to. can be carriers of activators of the Q fever, plague, brucellosis, hay fever, but epidemiological and epizootological value A. to. at these infections it is not defined. And. to. transfer also activators arboviral diseases (cm).

A.k. cause extensive damage to livestock production. During mass attack they exhaust animals, especially sheep and poultry; stings of mites can cause paralysis in animals.

For fight with And. to. in inhabited and economic constructions apply contact insecticides with long residual action.

A rational measure of fight against mites is construction of new modern houses and rooms for the cattle. To be saved from attack And. to., it is impossible to have a rest and spend the night in caves, grottoes, about holes, and also in old mud houses which can be populated with mites.

See also Mites , Arachnoid , Arthropods .

Bibliography: The multivolume guide to microbiology, clinic and epidemiology of infectious diseases, under an edition of H. N. Zhukova-Verezhnikov, t. 5, page 383, M., 1965; Pavlovsky E. H. The Argasidae Canestrini family, in book: Mites of rodents of fauna of the USSR, under the editorship of E. N. Pavlovsky, page 366, M. — L., 1955; Pospelo-va-Shtrom M. V. Kleshchi — ornito-dorina and their epidemiological value, M., 1953, bibliogr.; Filippova H.A. Argasovy mites (Argasidae), Fauna of the USSR, Arachnoid, t. 4, century 3, M. — L., 1966, bibliogr.

I. M. Grokhovskaya.