Abstract
To prevent the spread of oak wilt, the population and dispersal of Platypus quercivorus must be reduced. Because this insect is an engraver of living Japanese oaks, freshly cut logs were used to collect the insects from 2010 to 2013 in 26 sites, and 47 examples were accumulated. These logs were then piled in the sides of the forest road and timber yards in the damaged areas or in the forests of Cryptomeria japonica around the damaged oak forests. Huge piles of logs do not dry for a long period and the favorable sites for their mating can be maintained. It is also known that kairomones that attract these insects are present in large quantities in the cross-section of these logs. We succeeded in inducing more than 10,000 insects / 1 m3 to the piled logs by attaching synthetic pheromones on them. With this method, insects could be collected from middle to heavily damaged areas. If logs are crushed before the emergence of new adults, this trapping method is effective not only for disinfestation but also for reutilizing the logs. The tips of the oaks can be used for fuel and in paper manufacture. Furthermore, we suggest the use of this method for forest regeneration, making stands younger by cutting old oaks. Thus, logging can be valuable for protecting from oak wilt, providing useful materials, and regenerating oak forests.
