Ophiostomatoid fungi and blue-stain in New Zealand

In New Zealand, there are approximately 1.7 million hectares of plantation forestry, with the primary tree species being Pinus radiata. The forestry industry and researchers in New Zealand are concentrated on finding an efficacious, economic, and environmentally sound method of preventing blue stain in P. radiata and other tree species. New Zealand relies on the exportation of wood and wood products, therefore it is not only crucial that blue stain is prevented to minimize the amount of downgraded wood products but also that the quarantine risk associated with blue stain fungi to export destinations is recognized. In order to address these concerns, a concentrated attempt to identify species of blue stain fungi present in New Zealand was undertaken starting in 1996 and lasting about 10 years. From this research, 13 known species of ophiostomatoid fungi and several unidentified species were isolated from various wood sources. Several were associated with the introduced bark beetles Hylastes after and Hylurgus ligniperda. The role of these beetles in vectoring fungi to logs was previously known, but recent research identified a role for H. after as a vector of these fungi to P. radiata seedlings during feeding attempts. The effects of New Zealand blue stain fungi on the structural integrity of P. radiata was evaluated, and it was concluded that these fungi only produce cosmetic, non-degradative defects in wood.