Host: The Japanese Forestry Society
Interaction among blue-stain fungi associated with larch bark beetle, Ips cembraeTwo experiments of the interaction among the blue-stain fungi associated with larch bark beetle, Ips cembrae were cariied out. The distribution of blue-stain fungi in the sapwood and inner bark from the living larch tree in which I. cembrae were artificially bored was examined. The most pathogenic blue-stain fungus, C.laricicola formed axially very large lesion in the inner bark, and also caused blue stain axially in the sapwood. The fungus tended to be isolated from the distal part of the lesion or sap stain. O.laricis less extended axially in sapwood and inner bark than C.laricicola. O.piceae and O.brunenno-ciliatum only isolated from the discolored part of inner bark or sapwood just adjacent to the gallery of bark beetles. Each blue-stain fungus associated with I. cembrae revealed showing different extension in the inner bark and the sapwood of the attacked larch. The mixture inoculation of two species of blue-stain fungi, by the combination of C.laricicola vs. O.laricis, C.laricicola vs. O.brunneo-ciliatum, and C.laricicola vs. O.piceaewas carried out. Changes of trees after the inoculation were observed. The progress of the symptom on trees inoculated with the combination of C.laricicola and O.piceae was obviously delayed, compared with that of trees inoculated with only C.laricicola. The symptom on inoculated trees with the combination of C.laricicola and O.brunneo-ciliatum was also less severe than that of single inoculation of C.laricicola.
