From Big Medical Encyclopedia

DEZINSITSIRUYUSHCHY MEANS (fr. des-prefix destruction, removal + lat. insectum an insect) — physical agents, chemicals and biological methods (factors) used for destruction of arthropods — infection carriers or causing material damage. Success of use of D. of page in fight against separate types of arthropods depends on knowledge of a row them biol, features: habitals at various stages of development and duration of terms of development depending on environmental conditions, a way and frequency of food of larvae and an imago (adult individuals), conditions of a rewintering of a look, terms of emergence of spring populations (see), quantity and terms of emergence of generation (see. Generation ), etc.

For each area separate biological features come to light phenological observations (see. Phenology ). These observations allow to define the most rational ways and ways of use of D. of page in specific conditions. Of page were applied by the population to extermination of insects from time immemorial (burning, boiling, poisons of a plant and mineral origin).

Physical agents of disinsection

Fire — burning of the invaluable objects occupied by arthropods; a burning of surfaces and objects in fight against bugs, mosquitoes, cockroaches etc.; boiling and processing by abrupt boiled water (extermination of louses, bugs, cockroaches); the water vapor and a dry hot air used in disinfection chambers (see). Low temperatures (to 5 ° below zero) are effective only for extermination of cockroaches in premises. From mechanical ways apply different traps to catching and the subsequent destruction of some types of arthropods (sticky paper, etc.).

Chemical Dezinsitsiruyushchy means

carry To chemical D.'s number of page: insecticides — substances for extermination of harmful insects; acaricides (see) — for extermination of ticks; egg-killers (see) — for destruction of eggs of insects and mites; Larvicides (see) — for destruction of larvae and caterpillars.

Chemical D. of page shall meet the following requirements: to possess pernicious action on arthropods and to exert minimum adverse effect on animals and the person; to kill arthropods at all stages of development for short term at the minimum dose; to have considerable firmness; not to lose efficiency at influence meteorol, factors; not to damage objects on which they are applied; not to frighten off arthropods, and whenever possible to attract them; not to have off-flavor; to have the simple production technology and to be fireproof.

Depending on ways of penetration of drugs to an organism of arthropods distinguish three groups of chemical D. of page: contact — getting through outside covers, intestinal — getting through a digestive tract, fumigants (see) — getting through respiratory tracts. This division has conditional character since many insecticides can be carried at the same time to two or even to three groups. At all ways of penetration into an organism of an arthropod the insecticide gets to a hemolymph, edges carries it on all organism. Toxic action (irrespective of ways of introduction) develops hl. obr. from the chemical reactions leading to disbolism and enzymatic processes, to defeat nervous and other systems. Some of contact poisons have the cauterizing (destroying) effect on body tissues of arthropods.

Efficiency of action of insecticides depends on their dose, ambient temperature, duration and completeness of contact of arthropods with drug and sensitivity of an arthropod to it in each stage of development.

Contact insecticides — the most numerous group of chemical D. of page; they are divided into synthetic insecticides, products of processing of some minerals and lesokhy. industries, and also vegetable matters.

Synthetic insecticides are the most widespread and differ in property is long to keep toxicity during the drawing them on a surface (so-called residual action).

Oxidate ethylxanthogenic to - you was the first synthetic insecticide implemented in medical practice — bisetilksantogen (drug «K»), received in 1938. In pure form this crystal substance of yellow color, with a specific smell; it is not dissolved in water and well dissolved in alcohol, ether, oils. It is applied in the form of soap «K» (mix of equal parts of a bisetilksantogen and laundry soap) in fight against louses in the form of 2% of an emulsion, the cut is moistened by pilar parts of a body. Then appeared several insecticides received by chlorination of turpentine — the chlorinated terpenes: SI, SK-9, penphene, polychlorcamphene, Strabane, polychlorpinene, hlorten.

Soap K, SK, SK-9 and biphenyl amine played a certain role in prevention of a sapropyra during the Great Patriotic War. With the advent of new synthetic insecticides the listed drugs (except soap K) are laid off.

In the 40th 20 century the insecticides relating to were offered to chlorinated hydrocarbons (see), striking a nervous system of arthropods: in 1942 — santobane (see), in 1945 — hexachlorocyclohexane (see). Both connections were synthesized last century, but their insecticidal properties are found only in the late thirties — the beginning of the 40th of the current century. In the next years chlorinated hydrocarbons are synthesized and implemented in practice some more: aldrin, dieldrin, heptachlor, etc.

Santobane (DDT) it is effective for destruction of many types of arthropods that caused wide use it in medical disinsection.

A lack of chlorinated hydrocarbons — their accumulation in fatty tissue at systematic hit in an organism of an animal at least in small amounts. In this regard the specified insecticides are not applied to processing of animals and places of their pasture, and also objects from where they can get to food of the person and to a forage to the cattle (warehouses, the food enterprises, etc.). Their use is allowed in premises for processing of walls, furniture and clothes.

Other negative property, to inherent not only chlorinated hydrocarbons, but also other synthetic insecticides, development of resistance to them in arthropods is. Stability develops gradually later 5 — 8 years' constant use of the same insecticide irrespective of forms of use. Stability — property reversible: after phase-out of an insecticide, to Krom stability developed, in each succeeding generation it gradually decreases and, at last, disappears.

From the middle of the 50th of 20 century gained distribution organophosphorous connections hlorofos (see), trikhlofos (trichlorometafos-3), karbofos, metilnitrofos, etc. These are highly toxic and high-speed D. page, on the mechanism of action — the enzymatic poisons detaining education cholinesterases (see), but possessing shorter residual action, than chlorinated hydrocarbons.

Trikhlofos (trichlorometafos-3) is included into group of the mixed aliphatic aromatic ethers thiophosphoric to - you; an oily liquid with specific off-flavor, in water it is insoluble, possesses residual action from 4 to 30 days (depending on climatic and meteorol, conditions). Release in the form of 30 — 50% of the concentrated emulsion forming at cultivation by water resistant working emulsions of white color and also in the form of alloy with the paraffin (pencils) containing 2% of a trikhlofos. Apply to destruction of eggs, larvae and dolls of flies — 0,1 — 0,2% of an emulsion; in fight against bed bugs — 0,1 — 0,2% of an emulsion and pencils, to-rymi draw strips in habitals of bugs; with fleas — 0,1% of an emulsion; with mites — 0,5% of an emulsion.

Karbofos (a synonym malathion) — connection from derivatives dithiophosphoric to - you; liquid with a strong specific smell; in water it is insoluble; is poison contact, intestinal and fumigant; duration of residual action from several days to one month depending on local conditions. 30% of the concentrated emulsion and pencils containing 5% of drug are produced in the form of powder the content of 4% of karbofos. Apply to extermination of flies — water emulsions of 0,5 — 1% of concentration, louses — powder, 0,15% a water emulsion for soaking of linen, irrigation of clothes and easy wetting of hair on a body, bugs — powders, pencils, cockroaches — powders, ticks — water emulsions, midges — powders, water emulsions.

Dibromine (orthodibromine is abroad known as K-3455, neyled) — liquid of light yellow color, with a slight specific smell. Let's easily dissolve in hydrocarbons of an aromatic series, in water it is insoluble. 4% dust of dibromine (mix of talc with a kaolin) is steady at storage. It is most effective concerning bed bugs and house flies. Absolute death them is reached at contact with a worked surface of 0,5 — 1 g/m 2 active ingredient of technical dibromine (50% concentrate of an emulsion) or 0,05 g/m 2 dust. Dibromine is less effective in fight against cockroaches. Their absolute death is possible at a consumption of dust of 0,5 — 0,75 g/m 2 .

Methylacetophos it is applied to fight against louses and cockroaches.

Metilnitrofos — a dense dark brown oily liquid with a slight smell; the hl is recommended. obr. for destruction of larvae of mosquitoes and in fight against mites. From foreign drugs in the USSR it is used metation — the drug similar to a metilnitrofos (it is made in ChSSR). Abroad organophosphorous insecticides — bromophos, ethylbromophos, nuvanol have distribution (a synonym: yodfenofos, alfacron), tsidiat, etc.

In a number of the countries the new connections relating to group of carbamates were widely adopted (see. Carbamic connections ).

Of page representing products of distillation of minerals and lesokhy. the industries, include the following substances: albikhtol, green oil, kerosene, phenol, cresols, distillation residues, turpentine.

Albikhtol in the form of 10% of an emulsion from paste (50% of an albikhtol and 50% of laundry soap) applied to extermination of louses.

Products of distillation of oil — kerosene, green oil, etc. — are effective for destruction of larvae of flies. From products of processing of black coal can be used: phenol in the form of hot soap and phenolic solution — against bugs; cresols in the form of so-called crude carbolic acid — means for destruction of larvae and dolls of flies in the earth and the decaying organic garbage; krezolsoderzhashchy drugs — lysol, naftalizol, kreoline — effective Larvicides against flies in the form of 10% of emulsions. Turpentine for destruction of bugs and fleas, and in the form of 10% of an emulsion and paste — for destruction of louses on pilar parts of a body was in pure form used. The listed substances have the unpleasant, long remaining smell, and some of them are dangerous in the fire relation; besides, the decaying organic garbage processed by them cannot be used as fertilizers.

From the vegetable contact poisons finding application in the past only some species of camomiles from the sort Pyrethrum kept the value (see. Pyrethroids ).

Intestinal insecticides use for extermination of cockroaches and flies, and also against larvae of mosquitoes, midges, mokrets (dust or spray reservoirs). In addition to already mentioned insecticides from group contact, acting and as intestinal, enter into this group D. of page: boric acid (see), borax, sodium fluoride, thiodiphenylamine, Paris green, Butadionum (see), etc.

Boric acid, borax, sodium fluoride are used in fight against cockroaches in the form of powder, solution, and by the last two drugs — in fight against a red house ant (add to baits).

Paris green, thiodiphenylamine are used for destruction of larvae of malarial mosquitoes. Before use drug is mixed with road dust, hydrated lime, talc, etc.

Fumigants come to an organism of an insect through respiratory system. It easily evaporating substances.

Methyl bromide — a liquefied gas, is used in cameras for disinsection of various objects and in fight against insects on sea vessels at the rate of 30 — 60 g/m 3 .

Ethylene oxide is used in cameras for disinfection and disinsection at the rate of 15 — 30 ml/m 3 it (is explosive).

Cyanhydric acid in medical practice is used for destruction of arthropods and rodents on vessels in the form of a cyclone B (the infusorial earth sated hydrocianic to - that with addition of the signaling connection) or cardboard circles (diskoid) containing 7,5 g hydrocianic to - you on one disk expected 1 m3 of the room. It is allowed to work with hydrocianic to - that only to the persons who had special training.

Such fumigants as hexachloroethane, methyl chloride, parapont and chloropicrin are much less often used in disinsection.

From among organophosphorous connections as fumigant has high insecticidal activity dimethyldichlorvinylphosphate — DDVF which is widely used in the form of vapors and aerosols in fight against insects on the area and in premises. In the latter case concentration in 0,3 mg/m is sufficient for death of insects 3 . Aerosol cans contain 1 — 2,5% of DDVF.

During the work with any drugs carrying a respirator (is obligatory and during the work with solutions and emulsions on benzene and benzene chloride — carrying a gas mask), rubber gloves and the clothes which are well protecting skin.

Biological methods

Biological methods (factors): cultivation and release of the males who underwent sexual sterilization (gamma irradiation, X-ray); sexual sterilization of insects of natural population; use of the connections having juvenile and hormonal activity; use of viruses, bacteria and their toxins; use of natural enemies of arthropods; use attractants (see).

Sexual sterilization of insects. At systematic release of the sterilized males in enough there is gradually an extinction of natural population.

Chemical substances (hemosterilyanta) depriving of insects of an opportunity to breed were discovered in 1952. Derivatives of a trietilentiofosforamid and amidophosphoric to - you concern to them. The most active drugs — thiophosphatide (tiotef), Dipinum, Phosphemidum and morfamid. During the feeding of insects (house flies, stable-flies, mosquitoes, etc.) the baits containing hemosterilyant there occurs their sterilization. Based on success of experiments on use of such substances, WHO was organized in India by the research department for studying of an opportunity and use of genetic methods of controlling in wide scales.

Juvenile hormones, being hormones a metamorphosis, are found in all insects at certain stages of their development and are absolutely necessary for the normal growth and development of younger larval age of insects. They are present at bigger or smaller concentration in a hemolymph of insects throughout larval development. At a stage of an imago juvenile hormones are regulators of a diapause of insects and functioning of gonads.

The initial idea of development of a gormonopodobny insecticide was based on Williams's opening (S. M. Williams, 1956) who established that processing of dolls of insects extract of juvenile hormones leads to disturbance of a morphogenesis and emergence of transitional impractical forms. The farnesol extracted by Shmialek (R. of Z. Schmialek, 1961) was the first chemical juvenile hormone. Afterwards a large number of analogs of the juvenile hormones having high activity was synthesized (altozid, altozar, etc.). Introduction of juvenile hormones on Wednesday where larvae of mosquitoes (reservoirs), flies (garbage), etc. vyplazhivatsya, allows to destroy insects at early stages of development.

The purified juvenile hormone easily gets through a cuticle of insects. Females of house flies and mosquitoes of Aedes after topikalny (local) drawing high doses of hormone lay impractical eggs.

High biol, activity and specifics of action in combination with a hypotoxicity for the highest animals do juvenile hormones perspective in fight against harmful insects. Their epoxyamide analog gives good effect in fight against red cockroaches, house flies, mosquitoes.

From a large number of the bacterial drugs recommended for pest control of page - x. plants, any is not used in medical practice as all of them were ineffective concerning arthropods — infection carriers.

Natural enemies of arthropods are parasitic nematodes, predatory larvae of a mosquito, water bugs, etc. Possibilities of their practical use are studied.

A certain impact on the number of generation of mosquitoes is exerted by use of such fishes as gambusia (see), Penicilia feeding on larvae of mosquitoes, and also fishes of Aptcheicus eating larvae of midges.

See also Disinsection , Desinfectants , Pesticides , Organophosphorous connections .

Bibliography: Berim N. G. Biological bases of use of insecticides, L., 1971, bibliogr.; Vashkov V. I., etc. Insecticides and their use in medical practice, M., 1965, bibliogr.; Gar K. A. Testing methods of toxicity and efficiency of insecticides, M., 1963, bibliogr.; Millers of H. N. Himiya of pesticides, M., 1968; The Guide to fight against insects and ticks carriers of causative agents of diseases of the person, under the editorship of O. N. Vinogradskaya, M., 1972, bibliogr.; The specification of pesticides, the lane with English, M., WHO, 1962; C of e of t of l and V. M N. Aerosol cans, L., 1970, bibliogr.; Tsetlin V. M. and In and l to about in and the p B. And. Physical and chemical factors of disinfection, M., 1969, bibliogr.; Hartley G. S. a. W e s t T. F. Chemicals for pest control, Oxford, 1969, Insecticide and fungicide handbook for crop protection, Oxford a. o., 1972, bibliogr.; Pesticide handbook — Entoma, 1975 — 1976, ed. by S. C. Billings Pennsylvania, 1975; R e an at R. Page of Insects and insecticides, Edinburgh, 1969.

V. I. Vashkov.