From Big Medical Encyclopedia

BIOLOGICAL METHODS OF CONTROLLING — a complex of the actions directed to use «live against live» i.e. one live organisms for fight against other organisms. To B. of m. carry also genetic methods and receptions physical. and chemical sterilizations.

B. m. apply long ago. So, in the middle of the century the essential role in fight against plague was played by the domestic cat destroying rats with fleas — the main carriers of the activator of «black death». In the eighties last century I. I. Mechnikov suggested to destroy harmful insects by means of activators of fungus diseases.

At the end of 19 and the beginning of 20 century the first progress in pest control of agriculture would be an incitement to B.'s development by m. The technique and technology of contents, cultivation, acclimatization and intra areal resettlement of various entomophages extended and improved. The attention to preservation of biocenoses, to agricultural actions, assessment of value and resettlement of larva-eating fishes increased in reservoirs where mosquitoes, midges and gadflies develop.

Nowadays B.'s theory of m. is based on the concept biogeocenosis (see), on multilateral studying of ecology and biology of harmful types and their enemies — predators and causative agents of the diseases competing and neutral types, and also a role of the environment — the soil, reservoirs, vegetation. B. m. include also special genetic, agricultural and physical. - chemical means.

In practice of biological control with insects of medical value the technique, experience and B.'s generalizations by m is used. at protection of cultures of agriculture, the wood and animals. Enters the list of arthropods of medical value apprx. 1000 types. They are known more than 1000 types of natural enemies (causative agents of diseases, parasites and predators) from which 2 — 3 tens types are used so far, is preferential against blood-sicking, carriers and causative agents of diseases of the person. Among larva-eating fishes (more than 100 types) a special role is played by a gambusia (see), acclimatization and resettlement a cut in the USSR promoted destruction of malarial mosquitoes. The useful role of many bird species and bats is known. Mermitida draw attention (nematodes this. Mermithidae) — parasites of blood-sicking flies; in the centers of stay they are capable to suppress populations of the owner. In the USA mermitid settle in population of mosquitoes, free from parasites; positive takes are received. Success and in experiences of resettlement on the Pacific islands of Tokelau of the activator of a fungus disease (Collomomyces stegomyiae Keilin) of larvae of Anopheles polynesiensis for the purpose of their destruction are achieved. It is established that waste products of choral seaweed are toxic for larvae of mosquitoes in such degree that their population sometimes completely perishes.

Genetic methods of controlling (sexual sterilization, induction of conditional lethal mutations, trans-species and intraspecific incompatibility, etc.) were practically repaid. Processing hemosterilizator or in gamma quanta of males leads to an otkladka of impractical eggs therefore the number of population of a harmful look decreases. Lethal mutation of a mosquito of Aedes aegypti — a carrier of yellow fever (at water temperature 30 — 37 ° from larvae males did not develop) is received. A number of scientists works on transformation of harmful types into harmless and even useful types by means of mutations which carriers are switched to food by weeds. The races of several species of harmful insects incapable are removed to to a diapause (see) and thereof perishing at a wintering. Trans-species and intraspecific incompatibility of natural populations of separate types is used. The populations which are subject to destruction sate with individuals reproduktivno of the isolated race. E.g., population of mosquitoes of Culex pipiens fatigans was liquidated on rice fields near Rangoon (Burma) by daily release of 5000 males cytologic of incompatible race.

The method of the «samtsovy vacuum» created by means of primanochny spraying by mix of an insecticide with sexual is perspective attractant (see Attractants), imitating a specific sexual smell. The newest way of fight against insects — use «matron» — a factor of a monogamy of females. Processing of females of a house fly and several species of mosquitoes to «matrons» (a secret of ferruterous cells of the semyaizvergatelny channel) prevents pairing and dooms them to infertility. The synthetic analogs of juvenile hormone which are sterilizing and slowing down development of harmful insects are made. Further development of B. of m. it is based on the integrated or complex systems of fight in which biological, genetic, chemical, agricultural, physical and other ways of influence are rationally combined.

Bibliography: Biological control with harmful insects and weeds, the lane with English, under the editorship of B. I. Rukavishnikov, M., 1968, bibliogr.; Veyzer Ya. Microbiological methods of controlling with harmful insects, the lane Czeches., M., 1972, bibliogr.; L and B r e to Zh. K. and With m and t To.’ Genetic methods of controlling with harmful insects, the lane with English, M., 1971, bibliogr.; Rubtsov I. A. Biological method of controlling with harmful insects, M. — L., 1948, bibliogr.; it, Natural enemies and biological methods of controlling against insects of medical value, M., 1967; Suitmenkh. L. Biological method of controlling with harmful insects and weed plants, the lane with English, M., 1964, bibliogr.

I. A. Rubtsov.