INFLUENCE OF WEATHER CONDITIONS ON THE DEVELOPMENT OF SIBERIAN SILKMOTH OUTBREAKS IN CENTRAL SIBERIA
O. V. Tarasova, V. E. Volkov
Siberian Federal University, Krasnoyarsk, Russian Federation
Keywords: population dynamics of numbers, mass reproduction, necessary and sufficient conditions, conditional probability, weather, air temperature, precipitation, hydrothermal coefficient
Abstract
It is known that weather affects the development of outbreaks of Siberian silkmoth Dendrolimus sibiricus Tschetv. breeding. In this regard, the purpose of these studies was to study the influence of weather factors - temperature and precipitation on the possibility of developing of Siberian silkmoth population outbreaks. For a correct assessment of the influence of climatic factors on the dynamics of the number of forest insects and the development of outbreaks of pests, the concept of necessary and sufficient weather conditions was introduced to facilitate outbreaks of phyllophages. An approach is proposed to assess whether certain weather conditions are necessary or sufficient for the development of outbreaks of the Siberian silkworm in Krasnoyarsk Krai. Selyaninov’s hydrothermal coefficient (HTC) was chosen as an integral indicator of weather conditions: the ratio of the amount of precipitation for a certain period to the average temperature for this period. The Bayesian approach was used to calculate the conditional flare probabilities. For various forests in the territory of Krasnoyarsk Krai in which outbreaks of the Siberian silk moth were observed, analyses were carried out for May, June, July, August, and September in the period from 1980 to 2017. Analysis of the relationship between weather conditions and the development of outbreaks of the Siberian silk moth showed that a necessary condition for the occurrence of an outbreak of this pest in Krasnoyarsk Krai is dry and warm weather in May of the year preceding the onset of the outbreak. However, dry and warm weather in spring - early summer is not a sufficient condition for a future outbreak, and additional indicators are needed to predict the outbreak. Nevertheless, when the weather with HTC < 1 is realized, it is necessary to start carrying out a more detailed monitoring of the state of the pest population. It seems that the proposed calculation method can be used to assess the effect of weather on the development of the population not only for the Siberian silk moth, but also for other species of forest insect pests.
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