Disinsectization

methods and agents of controlling arthropods (insects and ticks) that transmit infectious diseases and damage food and agricultural products and human dwellings. One may distinguish medical, veterinary, and agricultural disinsectization.

Disinsectization methods are directed toward creating conditions unfavorable to the reproduction and development of arthropods (preventive disinsectization) and toward their complete extermination (exterminatory disinsectization). Preventive medical disinsectization includes systematic washing of the body and change of linens, which prevents reproduction of body lice; frequent cleaning of premises; and beating of soft furniture; shaking out of bedclothes, which prevents reproduction of bedbugs, fleas, moths, and cockroaches. Systematic removal from populated places of solid wastes and the establishment of sewer systems prevent development of houseflies and other flies. Drainage of swamps and purification and deepening of rivers decrease the possibility of breeding of mosquitoes, gnats, biting midges, bloodsucking flies, and other insects.

Exterminatory disinsectization includes the use of chemical, physical, and biological means that act destructively on all stages of arthropod development. Used as insecticides in the chemical method of disinsectization are chlorinated hydrocarbons, phosphororganic compounds (including chlorophos), pyrethrum, borax, and sodium fluoride. These substances penetrate the bodies of arthropods through the cuticle (contact insecticides), the respiratory tract (fumigants), or the intestinal tract (intestinal poisons); some preparations contain a combination of these properties. Insecticides are used in the form of solutions, powders, and aerosols. Besides insecticides, repellents are also used in disinsectization.

The physical method of disinsectization is based chiefly on the use of high temperatures, and, to a lesser extent, of lower temperatures and physical destruction of some individual insects. Temperatures of 50° C or higher have a destructive effect on arthropods; therefore, hot air, steam, and hot water are widely used for the destruction of lice, bedbugs, flies, and fleas. Also practiced is mechanical capture of arthropods in traps (flies, cockroaches, mosquitoes, pharaoh ants, and ticks) and on sticky paper (flies, mosquitoes, and gnats) and picking of insects and ticks from the bodies of humans and domestic animals.

The biological method of disinsectization is based on the use of the natural enemies of arthropods, such as pathogenic microbes, viruses, and parasitic and predatory insects, capable of causing extensive epizootic disease and destruction of arthropods. Also used are ionizing radiation and certain chemical substances (ethylenimine compounds), derivatives of azaridine, folic-acid antagonists, and pyrimidine, glutamine, and purine, which cause sexual sterilization of arthropods or anomalies in their development, as a result of which the arthropods lose their ability to produce offspring.

Veterinary disinsectization destroys insects and ticks that damage the health of animals and lower their productivity. The objects of veterinary disinsectization are animals, animal-breeding and poultry-breeding premises, farms, warehouses and enterprises that process raw materials of animal origin, slaughterhouses, meat combines, transport, and other objects under veterinary-sanitary supervision.

One may distinguish preventive veterinary disinsectization, which is conducted periodically for the purpose of preventing mass proliferation and spread of insects and ticks, and exterminatory disinsectization. Chemical, physical, mechanical, and biological agents and methods are used in veterinary disinsectization. Most widely used are chemical agents, particularly chlorophos, DDVP, malathion, Baytex, amidophos, Trolene, trichlormetaphos-3, Sevin, dicresyl, sodium arsenite, polychlorpinene, preparations based on the gamma-isomer of hexachlorocyclohexane, and the like. Treatment is conducted by the veterinary disinfection machines DUK and LSD-2M, aerosol generators, hand sprayers, dusting machines, and other mechanisms.

Agricultural disinsectization includes destruction of harmful insects on sowing and planting material, in stores of food and fodder products, and technical raw materials in warehouses and at milling and groats enterprises. Usually chemical disinsectization is conducted; it consists in fumigation with methyl bromide, dechloroethane, and other chemicals; treatment of premises with aerosols and spraying with insecticidal fluids; and dusting of seeds. Also effective against pests of cereals and cereal products is mechanical disinsectization—clearing premises of spills of grain or grain products, cleaning of grain on grain-cleaning machines, and so on. New methods of disinsectization are being studied, including the use of high-frequency currents, infrared rays, and ionizing radiation.