Abstract
Numbers of entry holes and of beetles emerged from logs of Quercus crispula that had been bored and killed by Platypus quercivorus, were investigated according to height above the ground. The number of entry holes tended to increase as the height above the ground decreased, but some were found higher than 10m above the ground. The number of beetles emerged per volume of sapwood or per entry hole tended to increase with height above the ground. Therefore, on some trees the number of beetles emerged lower than 2m high above the ground was less than 30 percent of the total number of beetles emerged from the trees. Although the width of the stem tended to decrease as the height above the ground increased, there was no difference between the width of sapwood where beetles propagate in the lower part of the tree and the upper part of the tree. Therefore, it was suggested that the low density of entry holes in the upper part of the tree decreased intraspecific competition for habitat space and increased the number of beetles emerged per entry hole.
