Krivets S.A., Kerchev I.A., Bisirova E.M., Debkov N.M. 2018. [Current distribution and forecasted expansion of the four-eyed fir bark beetle Polygraphus proximus Blandford, 1894 in an invaded area of Tomskaya Oblast’ (Western Siberia)] // Euroasian Entomological Journal. Vol.17. No.1: 53–60 [in Russian, with English summary].
Institute of Monitoring of Climatic and Ecological Systems, Russian Academy of Sciences, Siberian Branch, Akademichesky Ave. 10/3, Tomsk 634055 Russia.
Tomsk Branch of the All-Russian Plant Quarantine Center, Frunze Ave. 109А, Tomsk 634069 Russia.
ABSTRACT. A species previously known as a Far-Eastern endemic, the four-eyed fir bark beetle Polygraphus proximus Blandford, 1894 (Coleoptera, Curculionidae: Scolytinae), introduced into South Siberia, has become one of the most aggressive pests in terms of the recent large-scale degradation of Siberian fir forests. The Tomskaya Oblast is the first region where it was authentically recorded in 2008 and a special investigation of its invasion began. The aim of this study is to summarize the data on the distribution of P. proximus in the Tomskaya Oblast over a 10-year period of extensive field research. Locations of the P. proximus were identified on the basis of characteristic signs of damage to fir trees revealed according to the ‘Rules of a mandatory verification of taxonomic identification of collected insects’. Currently, the fir bark beetle has been detected in 13 districts of the Tomskaya Oblast, where it causes the death of the Siberian fir Abies sibirica Ledeb., 1833. The most widespread and highest population densities of P. proximus are found in the south-eastern districts, located on the right-hand bank of the Ob’ River in the area of the initial stage of invasion, where Siberian fir forms degradated stands. Total area of the bark beetle distribution is more than 100,000 km2 (256 km from S to N & 435 km from W to E). The northern limit of the current boundary of the alien species expansion coincides with the northern boundary of the southern taiga forest area. Further spread to the north and west of the region is forecast due to degradation of fir and mixed stands with fir, also caused by the outbreak of Siberian moth Dendrolimus sibiricus Tschetv., 1908 which began in 2015.
KEY WORDS: Polygraphus proximus, invasive area, Tomskaya Oblast’, Western Siberia.