From Big Medical Encyclopedia

FLIES — dipterous korotkousy insects of a suborder of Brachycera Cyclorrhapha.

The suborder combines apprx. 70 families considerably differing from each other as on a structure, and features of biology.

Value M. in the nature and for the person variously. Among them there are both useful, and harmful types. Padalny M.' larvae promote processing of the corpses of animals accumulating in the nature, flower M. are pollinators of plants, mu-hi-takhiny — parasites of harmful insects etc. Big group M. — wreckers of crops (see). Many types of M. belong to carriers of activators of a number of dangerous diseases of the person and animals (see. Carriers ).

Fig. 1. The diagrammatic representation of a structure of the head and the oral device of not blood-sicking fly (Musca domestica) — at the left and a blood-sicking fly (Stomoxys calcitrans) — on the right: 1 — a facet eye; 2 — short moustaches; 3 — bristles of moustaches; 4 — the main part of a proboscis of the licking type; 5 — the bottom of a proboscis; 6 — sucking blades; 7 — a palpus; 8 — a proboscis of the drilling type.

Coloring of a body of M. from opaque dark or light gray to metal brilliant blue or green. The sizes vary within 1,5 — 18 mm. The head is svobodnopodvizhny, roundish with big compound eyes. The oral device at the majority of types of sosushche-licking, more rare than the drilling type (fig. 1); sometimes the oral device is completely reduced (e.g., at a gadfly). Short moustaches of three-chlenikovye. (Ari-cost) the last joint with a naked or plumose bristle. Legs of a usual structure, a pya-tichlenikovy pad comes to an end with couple of claws and pulvill — the suckers allowing M. to creep on vertical surfaces. The abdomen oval or ovoid, consists of 5 — 8 visible segments.

Fig. 2. Outward of some flies it (is increased): 1 — a house fly (Musca domestica L.); 2 — a fly a stable-fly (Stomoxys calcitrans L.); 3 — a meat fly (Calliphora ura-lensis Vili); 4 — a volfartova a fly (Wohlfahrtia magnifica Schin.); 5 — a cheese fly (Piophila casei L.); 6 — a fruit fly (Drosophila funebris F.); 7 — a hypodermic gadfly of a cattle (Hypoderma bovis L.), at the left — an imago full-scale, on the right — an adult larva.

Distinguish group from a large number of types of M. synanthropic, connected in a varying degree with the person (fig. 2). Carry types to this group this. Muscidae, Calliphoridae, Sarcophagidae, Hippobos-cidae, Syrphidae, Piophilidae, Dro-sophilidae, Oestridae, Hypodermatidae, Gasterophilidae, etc., differing in the biology, ecology and extent of contact with the person.

Fig. 3. Diagrammatic representation of a larva of the III stage of flies this. Hippoboscidae and sorts Glossina (this. Muscidae): B1 — B10 — belly segments; In — valikoobrazny swellings of belly segments; G1 — G3 — chest segments; D1 — a perednegrudny stigma; D2 — a back stigma; P — pleural sclerites; PTs — pseudo-cephalus.

Vast majority of M. oviparous. One-time fertility fluctuates from 20 to 300 eggs. At the same time there are viviparous types. So, this M. Sarcophagidae give rise to a larva of the I stage, this M. Hippoboscidae and sorts Glossina (this. Muscidae) — a larva of the III stage, ready to pupation. Larva of worm-shaped type (fig. 3). Difficult arranged oropharyngeal device is armed strongly hitinizirovanny kryuchyam. Larvae by means of the tracheas opening in two couples of stigmas breathe: front couple is located on the first chest, back on the eighth belly segments. Features of a structure of stigmas are used in M.

Lichinki's systematics occupy various substrates: the decaying plant and organic residues, food waste, a dung of animals, etc. Therefore the main places of breeding of M. in settlements are dustbins, dumps, not canalized toilets, livestock farms, catering establishments, pshtsekombinata and shops (at disturbances of sanitary standards of operation).

Life expectancy of adult M. makes 2 — 3 weeks. Throughout this period each 2 — 3 days the female postpones a portion of eggs. Adult M. are active only during the light period of days at a temperature not below 15 ° — repeatedly visit as garbage the receiver and, the decaying waste, manure, and housing of the person. M can become easy mechanical carriers of causative agents of intestinal infections.

On character of food of M. divide into several groups.

Afag — M., in adulthood which are not eating — gadflies (see); nektarofag — the adult M. eating nectar of flowers and vegetable juice — volfartova fly (see), etc.; a coprophagy — the adult M. eating excrement of animals and the person and also foodstuff, kitchen garbage etc. (house and room M., etc.); necrophages, or padalny M. — preferential eating on corpses of animals, meat waste, also excrement of animals and the person, products of plant origin (green meat M., blue padalny M., etc.); erythrophages — M. eating blood. Erythrophages divide on erythrophages optional and obligate. The first — not blood-sicking M. eating the blood exuding from wounds, allocations from mucous membranes etc. (a market fly, etc.). Obligate erythrophages are the blood-sicking M. eating only blood of the person and animals — a fly a stable-fly, tsetse fly (see), etc.

Epidemiol, value of different types of synanthropic M. is defined by extent of their contact with the person, edges depends on character of food of larvae and an imago.

Distinguish settlement, semi-settlement and pasturable types from synanthropic types of M. Settlement M. are so closely connected with the person that such types as Musca domestica, Fannia canicularis and Musca sorbens out of the settlement, as a rule, do not find at all.

The majority of necrophages belongs to semi-settlement types since can vyplazhivatsya on meat waste and corpses of animals both in the settlement, and in the wild nature (this. Sarcophagidae, types of the sorts Lucilia, Calliphora this. Calli-phoridae).

Carry to pasturable types many optional and obligate erythrophages, nektarofag and afag. These M. attack on animal hl. obr. on pastures for food blood (types of the sorts Lyperosia, Haematobia, Musca, Hydrotaea) or otkladka of eggs (Wohlfahrtia magnifica, a gadfly). The person who is on a pasture can be also attacked by pasturable types of M.

Settlement types of M. can serve as indicators a dignity. conditions of the inhabited places. As on each substrate certain types of M. vyplazhivatsya, their mass quantity in the settlement indicates a dignity character. disturbances. E.g., high number within the city of Musca domestica and Protophor-mia terrae novae indicates untimely garbage removal, M. of types of Fannia canicularis, Calliphora uralensis or Muscina stabulans — insanitation of neka-nalizirovanny toilets; the abundance of Ravinia striata, Bercaea haemorrhoidalis or Musca sorbens tells o fecal pollution of the soil etc.

Synanthropic M. are mechanical and specific carriers of a number of infections and invasions, activators of mioses of the person and animals. In the mechanical way M. transfer cysts of a dysenteric amoeba and egg a worm, causative agents of such bacterial intestinal infections as cholera, a typhoid, a paratyphoid In, dysentery, etc. Terms of survival of bacteria on a body and in M.'s intestines are quite considerable, napr, a tubercular stick up to 16 days, disputes of a malignant anthrax to 13 — 20 days. Optional erythrophages are carriers of infectious conjunctivitis and trachomas, obligate erythrophages — mechanical carriers of a tularemia, a brucellosis and nek-ry infections of page - x. animals. So, an obligate erythrophage a tsetse fly (Glossina palpalis) — a specific carrier of a tsetse-fly disease, or African trypanosomiasis. Larvae of nek-ry types of M. from group of afag and necrophages parasitize in an organism of hematothermal and are activators of high-quality and malignant mioses of the person and animals (see. Miaza ).

Fight against M. and their larvae has multidimensional character. A radical measure of fight against settlement types of M. is timely and full removal of food waste and other accumulations of the decaying organic matters from the territory of settlements. Removal of garbage needs to be carried out regularly at least 1 time in 3 days (according to terms of development of larvae of Musca domestica), at the same time dustbins shall be cleared carefully for the prevention of breeding of M. in the remains of garbage at the bottom. It is necessary to store in rural areas correctly and to regularly take out manure.

From chemical methods of controlling use of larvicides in effluent is the most effective; use of larvicides in solid waste is less effective. At a large number of M. in rooms it is possible to carry out processing of walls insecticides (see). Effectively also use of the poisoned baits and adhesive tapes (see. Disinsection ).

Bibliography: Derbenyova-Ukhova V. P. Flies and their epidemiological value, M., 1952; The Guide to medical entomology, under the editorship of V. P. Der-benevoy-Ukhova, page 176, M., 1974; Shta-kelberg A. A. Synanthropic dipterous faunae of the USSR, M. — JT., 1956.

S. N. Zarechnaya, E. V. Mahanko.