Bursaphelenchus xylophilus
[5] In 1969, Japanese plant pathologists Tomoya Kiyohara (清原友也) and Yozan Tokushige (徳重陽山) discovered many unfamiliar nematodes on dead pine trees around the Kyushu islands in Japan.The forests of Portugal have been particularly impacted, as the most abundant species, the maritime pine, comprising almost two-thirds of all trees, is susceptible to the nematode.Many factors have contributed to the global spread of the nematode, including human activities, in particular infested timber exports, as well as climate change and ecological disturbance.[10][14] B. xylophilus is distinguished by three characteristics: the spicule is flattened into a disc-shaped cucullus at the tip, the front vulval lip is flap-like, and the tail of the female is rounded.In nature it reproduces most rapidly in the summer, producing large numbers of individuals that spread throughout the resin canal system of susceptible pines, into the trunk, the branches, and the roots.If living tree cells are no longer available the parasite feeds and reproduces on the fungal hyphae growing in the resin canals.The "high resistance" pines are rarely killed by the nematode, but young saplings or trees in weakened condition may succumb.[20] In Japan, scientists and forestry officials believe the most effective preventative technique is the removal of sawyer beetles, the vector of the nematode.In Japan, organophosphorus compounds and neonicotinoids like fenitrothion, malathion, acetamiprid, and thiacloprid are typically used to treat the adult sawyers.Infected trees are cut and either burned or chipped, soft wood timber is stripped of its bark to prevent oviposition by vectors, and all lumber shipped overseas is either fumigated or kiln-dried.