1999 Volume 3 Issue 2 Pages 81-84
A mass mortality of Japanese cedar (Cryptomeria japonica) trees occurred in Komaki-yama in Aichi Prefecture, Japan, in May 1997. A newspaper reported that the mortality was caused by Xeris spectrum emerged from the trees. We doubted this explanation and investigated the true cause of the mass mortality. The dead trees had elliptic emergence holes and symptoms of hatikami on the trunks, suggesting that the sugi bark borer (Semanotus japonicus) had attacked them. Moreover, a star-like discoloration characteristic of attack by Urocerus japonicus was also seen. In 1998, we caught a large number of sugi bark borer adults with sticky-band traps, suggesting that these insects were the primary cause of the cedar mortality. Perhaps, oviposition by U. japonicus transmitted a fungus to the cedar trees that had been weakened by the sugi bark borer attack, and Xeris spectrum exploited this circumstance.
