Bees ascospherosis spread in the Russian Federation apiaries

The purpose of the study is to review the distribution of ascospherosis of bees in apiaries of the Russian Federation. The paper presents the results of the analysis of scientific publications and data from veterinary services on the spread of ascospherosis of bees in different years in apiaries in 12 regions of the Russian Federation (Altai, Krasnoyarsk, Kemerovo, Kurgan, Moscow, Novosibirsk, Omsk, Sverdlovsk, Tomsk, Tyumen Regions, the Republic of Tatarstan and Udmurtia). Epizootic survey of apiaries from the Urals to Eastern Siberia in 1981-1987 showed that out of the number of studied 128 apiaries, the disease was detected in 113, which amounted to 88.28%. At the same time, regions unfavorable for ascospherosis were identified: in the Tyumen Region - 15, the Sverdlovsk Region - 7, the Kurgan Region - 1, the Omsk Region - 2, the Novosibirsk Region - 5, the Tomsk Region - 2, the Kemerovo Region - 2, the Krasnoyarsk Region - 8, the Altai Region - 3. 54 apiaries in 12 districts of the south of the Tyumen Region in the period from 2006 to 2020 showed that all the studied farms were unfavorable for ascospherosis. In Tatarstan, when examining 5,000 bee colonies, ascospherosis was detected in 64.0 %, in Udmurtia - in 77.5 % of cases. In greenhouse farms of the Moscow Region, a significant infection of bee families with ascospherosis and European foulbrood was registered; in the Tomsk Region, infection of bees with ascospherosis was 19.4 % among the identified mycoses. As the analysis of literature data shows, ascospherosis is widespread in the apiaries of the Russian Federation. Most often, mycosis occurs in the form of a mixed invasion-infection with varroatosis.