Efficacy of commercial wood preservatives against Bursaphelenchus xylophilus, a quarantine organism in Europe

Bursaphelenchus xylophilus, the pine wilt nematode (PWN), is a quarantine organism with a high potential to damage conifer forests in Europe. This has driven the European Union to protect forest stands from the propagation and dispersion of this pathogen. However, the current control measures have been unsuccessful in preventing the dispersion of this organism, as it continues to be detected in wood material through commercial trade. Timber is a material treated with specific products against wood decay organisms, and is now, additionally submitted to thermo-treatment in accordance with International Standards for Phytosanitary Measures No. 15 (ISPM-15) to control PWN. The industrial sector is concerned whether this treatment is sufficient and the current anti-decay wood treatments are effective against this nematode. For this reason, the objective of this work was to evaluate the efficacy of the permitted wood products against B. xylophilus in blue-stained and non-stained green and dry wood in Pinus pinaster Ait, the most sensitive Pinus species. The results show that the anti-sapstain products tested are effective against PWN in green sound wood, but they do not present the same protective behavior in blue-stained wood. The results for other products employed on dry wood (stained and non-stained) show that almost all of them are effective against this nematode. In consequence, timber protected by means of commercialized wood preservatives might be a good way to control PWN in the wood industry, even being a valid alternative and in some situations preventing the application of ISPM-15.