In 1998, Japanese plant pathologists group was isolation, inoculation and reisolation the dead tree.
The first obvious symptom was that the leaves wilted, and many small holes appeared on the trunk.
If you cut the dead tree, you would discover the xylem had been discolored to brown.
[2] The oak trees react plugging their xylem with gum and tyloses for blocking the fungus spreading.
The majority of this disease treatment is cut down the dead oak trees, and killed the vector ambrosia beetles by burned timber or infused insecticide.