The Ussuri Polygraphus proximus Beetle: Spread in Siberia and Implications for Forest Health
Researchers from Siberian Federal University have mapped the spread of the invasive bark beetle Polygraphus proximus Blandford, known as the Ussuri polygraph. Their findings show the pest originated in the Far East and moved westward into Siberia, crossed the Ural Mountains, and reached the border regions of Kazakhstan. The expansion poses a real threat to fir plantations across Russia, a notice reported by the Ministry of Education and Science following consultations with the research community.
In its native Far Eastern range, the beetle is typically a secondary pest, attacking only weakened or wind-damaged fir trees. Over centuries, Far Eastern fir species developed defenses that limit damage. Once the insect entered Siberia, it demonstrated aggressive behavior by attacking healthy trees, including the Siberian fir, which had not previously faced this foe. This shift indicates the pest can adapt to a new host and threaten forest stands that were once resistant. A leading researcher at the Siberian Federal University’s Institute of Forestry and the VN Sukachev Institute notes the Siberian fir’s defenses proved insufficient against the alien invader.
The beetle has already established populations across multiple Siberian regions and beyond the Urals. Moreover, established foci of Ussuri polygraph spread have been observed in the Krasnodar region for several years, signaling ongoing or growing outbreaks in the south as well as the east.
Identification of this bark beetle hinges on examining the insects and their remnants. Experts found evidence beneath the bark of damaged Siberian fir trees, confirming the presence of Polygraphus proximus in affected stands.
Given that local predators and parasitoid insects do not rapidly suppress the alien population through natural predation, experts emphasize that human intervention is essential to regulate numbers and prevent further dispersal. Researchers warn that the species is expanding into new territories, underscoring the need for proactive management and monitoring across forested regions.
Contributions to the study came from Siberian Federal University and the Forestry Institute named after VN Sukachev SB RAS, along with Altai and Tomsk State Universities. Support also came from the Russian Academy of Sciences’ Forestry Institute and the Russian Science Foundation, highlighting the collaborative effort to understand and mitigate this pest.
Recent discourse highlights the ongoing challenges posed by invasive bark beetles and the importance of early detection, coordinated management, and international cooperation to preserve forest ecosystems across Russia and neighboring areas.