New Zealand Journal of Forestry (1998) 42(4): 30–34
©New Zealand Institute of Forestry
Pine pitch canker - the threat to New Zealand
Pine pitch canker caused by the fungus Fusarium subglutinans f sp. pini is a serious disease of many species of pine and has severely affected Pinus radiata in California since its discovery in 1986. The fungus, together with its bark beetle vectors, causes dieback, reduced growth, reduced timber quality due to stem deformation, reduced seed crops and tree mortality. A number of potential pathways for the entry of the pitch canker fungus into New Zealand are recognised. These are live plant material, Pinus seed, plant debris associated with used logging machinery and vehicles, timber used as wood packaging and insects known to transmit the disease in North America. There would be no climatic barriers to the fungus or to introduced vectors if they escaped the quarantine net. If the fungus were to become established in New Zealand its spread would probably be limited by the paucity of suitable resident insect vectors. Hylastes ater, Hylurgus ligniperda and Pineus laevis would be the most likely
* NZ Forest Research Institute, Private Bag 3020, Rotorua.
vectors of the disease. Airborne inoculum appears to play no part in disease spread in California but it is a major source of infection of Pinus species in the south-eastern United States. Its potential importance in New Zealand cannot be predicted.