Survival of Bursaphelenchus xylophilus and Monochamus galloprovincialis in pine branches and wood packaging material.
Survival and development of Bursaphelenchus xylophilus (pine wood nematode) was studied for up to 40 weeks in Pinus pinaster sawn wood and branches: 30 boards (1200×100×25 mm), 30 long-blocks (1200×95×95 mm), 10 pine branches with bark and nine branches without bark (1200 mm long). The nematode was found in all materials and through the entire sampling period, with higher abundance in the sawn wood (boards and long-blocks). In the initial period B. xylophilus reproduced abundantly and a population peak was detected at 8-12 weeks. Subsequently, the populations declined and became dominated by third-stage resistant larvae (JIII), and in the final sample nematode abundance was very low. Nematode decline in the wood was correlated with a decrease in the moisture content (MC) to below fibre saturation. Survival of the insect vector Monochamus galloprovincialis was also assessed in sawn boards (1200×100×25 mm, n=31) and blocks (160×95×95 mm, n=40). The majority of the larvae were killed when sawing the wood, although some adults successfully emerged from the boards (10% survival) and blocks (37%). These results represent a contribution to the quantification of the risks of dispersing pine wilt disease through wood packaging materials, confirming that untreated wood can support healthy and abundant B. xylophilus populations for sufficient time for vectors surviving the sawing process to complete their development, to emerge and disperse the nematode.