Invasive beetle threatens Japanese fruit orchards

The invasive red-necked longhorn beetle (Kubiaka Tsuyakamikiri) is causing significant damage to fruit orchards across Japan, threatening traditional crops such as plums, peaches, and prunes. The beetle, native to China and the Korean Peninsula, lays eggs in trees of the Rosaceae family; the larvae then consume the interior of the wood, eventually killing the tree.

In Saitama Prefecture, the Obuse plum groves—one of the region's three major plum forests—are under threat. Approximately 10% of the 5,000 plum trees in Obuse have already been affected. Some farmers have been forced to abandon their businesses because trees must be felled to prevent spread, and new trees take up to 15 years to bear fruit. Challenges in mitigation include the high cost of specialized netting and the fact that pesticides used for cherry trees cannot be applied to edible plum trees.

In Nagano Prefecture, the infestation is also expanding. Local authorities have begun distributing specialized pesticides to farmers in areas like Saku City and Sakuho Town to combat the spread. Farmers in these regions have expressed deep concern that the pest could destroy long-standing fruit-producing traditions in the area.