From Big Medical Encyclopedia

LARVICIDES — means for destruction of maggots, it is preferential with full transformation (flies, mosquitoes, mosquitoes, fleas, etc.), the causative agents of infectious diseases which are carriers.

On the mechanism of action of L. conditionally subdivide on contact, intestinal, fumigatsionny, however many of them possess the combined action, napr, fumigatsionny and contact, contact and intestinal etc. Larvicide properties most of modern insecticides of group of organophosphorous connections (trichlorometafos, karbofos, DDVF, etc.) and chlorinated hydrocarbons has.

Efficiency of L. depends on degree of their toxicity for larvae, physical. - chemical properties of drugs, a form of their use (dust, granules, water and oil solutions, emulsions), character of the processed substrate, klimatogeografichesky features, etc.

L. apply by means of various disinfection devices (see). Ways and terms of use are established according to bioecological features of larvae of different types of insects, taking into account the environment of their dwelling, time of mass breeding, conditions of development etc.

L have the greatest practical value. for destruction of larvae of flies and mosquitoes; they are applied always in a complex of the actions directed to prevention of mass breeding of insects, napr, for the prevention it is filled in also breeding of flies of a wall of outdoor bathrooms and pomoynitsa shall be without cracks, doors of bathrooms and a cover of pomoynitsa densely to be closed. Collecting solid garbage needs to be made in the closed removable tanks (tanks, containers). The territory about pomoynitsa and vygreb is asphalted or concreted on 1,5 m from their edges (distance of possible creeping of larvae of flies). Receivers for solid garbage establish on the concreted (asphalted) platforms of such sizes that from receivers of garbage to the region of the platform there were also not less than 1,5 m.

For destruction of larvae of flies use karbofos, hlorofos, trichlorometafos, hexachlorane, polychlorpinene, etc., with water emulsions or solutions of which evenly fill in the surface of liquid or solid garbage and sewage, and also soils around collections of garbage, etc. (Delarvation) earlier widely applied surface processing of water in reservoirs to destruction of larvae of mosquitoes oil, thiobiphenyl amine, Paris green, calcium arsenite, arsmaly and other delarvatsionny means. Possess high larvicide action karbofos, trikhlofos, etc.; they kill larvae of mosquitoes of the sort Aedes, Culex, Anopheles and midges. However all these drugs perniciously affect useful inhabitants of reservoirs therefore their use is admissible only for processing of the swamps, drying channels and reservoirs which do not have economic value.

The dosage of drugs depends on the nature of overgrowing of a reservoir, its depth, a species of the occupying blood-sicking insects, a geographical location and the equipment used during the processing. In the reservoirs which grew with vegetation apply big dosages, than in not overgrown. At aviachemical treatments the consumption of working solution makes 25 — 30 l/hectare, and during the use of the mechanized land equipment — 100 — 200 l/hectare.

Due to the task of environmental control and inadmissibility of disturbance of integrity biocenoses (see) the volume of delarvatsionny works with the purpose of destruction of larvae of blood-sicking insects it was sharply reduced. Preference is given to extermination of adult dipterous insects.

During the use of L. it is necessary to observe measures of personal and public security for prevention of accidental poisoning of people and useful animals. Working with toxic chemicals it is necessary to provide with the devices and overalls protecting respiratory organs, skin and eyes from hit of drug (a dressing gown, an oil-cloth apron, goggles, gumboots, rubber gloves, respirators).

Preparation of working solutions, packaging of drug are carried out in specially equipped, well aired room or in the open air. It is possible to store drugs only in non-residential premises, especially for it equipped, without allowing frost penetration in drug in winter time. On the ware used for preparation of working emulsions (suspensions) there has to be a text «Poison». After work it needs to be washed with hot water with soap and soda. This ware, and also an empty container cannot be used for other purposes.

In operating time yet overalls are also not taken off, hands by warm water with soap are not washed up, it is impossible to eat food, to drink, smoke.

See also Disinsection , Dezinsitsiruyushchy means , Pesticides .

Bibliography: Vashkov V. I., Kerbabayev E. B. and Dremova V. P. Midges in the oil-and-gas Areas of Siberia and fight against it, L., 1968; Vashkov V. I., etc. Insecticides and their use in medical practice, M., 1965, bibliogr.; Putintseval. S. Difos-perspektiv-ny an insecticide, in book: Sovr, methods and means of disinfection and sterilization, under the editorship of T. I. Istomina, page 134, M., 1977.

F. T. Korovin.