2012 Volume 94 Issue 1 Pages 31-35
In 2010, the number of living trees attacked by the Oak borer Platypus quercivorus was investigated in a Quercus crispula forest which had or had not been attacked by the borer in the previous year. The attack density per tree was correlated negatively with that in the previous year, except for one data that showed the maximum density in each year. Thus, the trees attacked by the borer in the previous year received fewer attacks than non-attacked trees, and the past-record effect of reducing tree mortality approximated 81%. These results suggest that further beetle attack and tree mortality were controlled on the living trees that had been attacked at a high density in the previous year.
