Fomin S. N., Barinov V. V., Myglan V. S. Siberian Silkmoth in the Republic of Tyva, the History of Studies

Received 26.04.2019

Siberian silkmoth (eggar) Dendrolimus sibiricus Tsch., (1908) is one of the most dangerous forest pests in the Republic of Tyva. Outbreaks of this phytophage in the republic occur frequently and cause significant damage to forests. Studies in Tyva were engaged by A. I. Cherepanov, N. G. Kolomiets, N. F. Reimers and others in the 50–70s of the XX century. They described the phenology of the Siberian silkmoth, the biological and ecological aspects of its life activity. In this paper we tried to summarize all the accumulated knowledge of the Siberian silkmoth in Tyva. On the basis of the collected and analyzed data we restored the chronology of the Siberian silkmoth outbreaks. We demonstrate that outbreaks of the Siberian silkmoth in the Republic of Tyva are most frequently observed in the forests of Shagonarsky, Chadansky, and Turan forestry districts. In total, five outbreaks were registered: in 1954–1966, 1969–1975, 1979–1985, 1997–2000, and in 2009–2011. Duration of outbreaks was 13–7–7–4–3 years and intervals without outbreaks were 2–1–2–1 years subsequently. The fragmented nature of the obtained data on outbreaks shows the need for their verification using dendrochronological methods. Correct performance of such an analysis is possible with the use of control tree species not susceptible to the Siberian moth damage and some parameters of the annual ring, for example, the optical density of wood.