THE STATE OF STUDY OF EDEMAGENOSIS AND CEPHENOMYIOSIS OF DOMESTIC REINDEER IN THE FAR NORTH-EAST OF RUSSIA

Gadfly invasion remains one of the main diseases of reindeer in the Magadan region and Chukotka. Prevention of damage caused by gadfly invasion, increasing the productivity and profitability of northern domestic reindeer husbandry determined the relevance of this work. The research was carried out during expeditions in the field conditions of the Markovsky reindeer farms (Markovsky district of Chukotka), the Yubileiny experiment production household (Khasyn district of the Magadan region), and the laboratories of the Magadan Research Institute of Agriculture (Magadan).The purpose of the work was to conduct a retrospective analysis of the state of knowledge of edemagenosis and cefenomyosis of reindeer in the Far North-East of Russia, which will form the basis of modern methods of combating these diseases. In the conditions of Chukotka and the Magadan region, the species composition of gadflies was determined: nasopharyngeal - Cephenomyia trompe and subcutaneous - Oedemagena tarandi. The seasonal dynamics, the number of subcutaneous and nasopharyngeal gadflies, the daily rhythm of their activity were studied to justify the timing and frequency of treatments. The mass flight of subcutaneous gadflies in the Magadan region is 47 days, in Chukotka - 26 days. The maximum number of subcutaneous and nasopharyngeal gadflies attacking reindeer is 34 in 30 minutes. The first appearance of gadflies in the forest tundra was noted 28-30 days earlier than in the tundra. The number of days of mass flight of gadflies in the forest-tundra is greater than in the tundra, which leads to a more intense invasion by larvae of the subcutaneous gadfly of deer grazing in the forest-tundra zone. In Chukotka, the infestation of females by larvae of the subcutaneous gadfly was 85.0%, calves - 91.0%, with the intensity of invasion - 102 and 97 larvae per animal, respectively; in the Magadan region, the females and calves are affected by 100.0%, with the intensity of invasion - 370 and 140 larvae per animal, respectively. Invasion of females by larvae of the nasopharyngeal gadfly in Chukotka was 75.0%, calves - 80.0%, with the intensity of invasion - 38 and 45 larvae per animal, respectively; in the Magadan region - the incidence of females - 86.0%, calves - 92.0%, with the intensity of invasion - 44 and 52 larvae per animal, respectively. Larvae of the nasopharyngeal gadfly were localized in the labyrinth of the ethmoid bone - 50%, in the choanae - up to 15% and on the nasal septum up to 35%. The degree of invasion of deer with edemagenosis and cefenomyosis depends on the place of grazing. In the forest-tundra zone, deer are 12-15% more infested than in the tundra zone.