Click on any
image for a more
detailed view

Significance

The disease has a different impact on U.S. exporters of wood products than on homeowners. Bursaphelenchus xylophilus is a quarantine organism in the European Union. Because of the number of susceptible pine hosts and suitable insect vectors in Europe, and the devastating impact the disease has had on native forests in Japan, China, Korea, and Taiwan, unseasoned wood from areas where the pine wood nematode was known to occur was banned in the European Union and China. In Japan, survival of pine trees in a stand can be less than 50% due to pine wilt. An exact measure of the economic impact of the ban on lumber exports from the U.S. and Canada cannot be directly made because of other variables, such as the changes in the Japanese economy and other market factors.

Canadian and U.S. exporters are working with researchers to develop wood treatments that kill the nematodes present in wood chips or other unseasoned lumber (Figure 12). Currently, heat-treating unseasoned lumber to a core temperature of 56°C (133°F) for 30 minutes is sufficient to satisfy the European Union that wood products are free of living nematodes or their beetle vectors. Researchers are studying the risk of pest introduction based on visual inspection of lumber.

Figure 12.