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Hokkaido Oaks Fall to Invasive Beetle Disease
15 Jan
Summary
- Oak wilt disease is rapidly spreading north across Hokkaido.
- Warming temperatures allow disease-carrying insects to survive winters.
- New strategy involves harvesting oak trees before infection occurs.

Oak wilt, a destructive tree disease, is rapidly spreading north throughout Hokkaido, Japan's northernmost main island. The disease, transmitted by insects, attacks oak species, leading to their eventual death. Experts warn that warming temperatures are a critical factor, allowing the insects responsible for transmitting the pathogen to survive the harsh winter months and accelerate the outbreak.
Recent surveys reveal a dramatic escalation in oak wilt cases. In fiscal 2011, only 15 trees showed signs of damage, but by 2025, officials confirmed 1,637 damaged trees across multiple cities and towns. The rapid spread overwhelms current extermination and containment efforts, requiring increased budget and manpower. Field crews also face risks from brown bears in remote forests.
Faced with the potential loss of valuable timber resources, communities are exploring early harvesting strategies. The town of Mori has partnered with a company to process oak wood before it deteriorates, aiming to supply the growing demand for whiskey barrels. This initiative offers potential business opportunities but underscores the urgent need to utilize timber resources before they lose their value.



