Pine wilt is a disease of pines that occurs on most Illinois pine species except white pine. The infected trees die quickly, usually within a season but sometimes sooner. The nematode pathogen that causes pine wilt is easily detected by extraction from the wood. Most plant labs confirm the nematode's presence by soaking wood discs in water overnight and examining the extract for the nematodes.
There is no cure for pine wilt. We can try to break the cycle of infection by removing infected trees as soon as possible, thus preventing spread of the nematode via Sawyer beetle vectors. Infected trees do not recover. If you have a brown pine tree in your landscape, remove it now. Brown pines are not going to recover. You can try bending branches to see if they are alive. If they snap when bent, they are dead. If all needles on the pine are brown, whatever the cause, remove the tree now. Dead pines may provide a place for wildlife, but a tree infected with pinewood nematode may also serve as a source of infection for pines within the flight pattern of Sawyer beetles. The beetles are still feeding now and may be spreading the nematodes as you read. The tree needs to be removed from the site and preferably burned, buried, or chipped. For more information on pine wilt, refer to Report on Plant Disease, no. 1104, or issue 12 of this newsletter.