Infected trees will show yellowing then death of the needles. White fungus patches form under the bark in the infected area. Stressed trees will be more susceptible. Pine wood nematode causes the needles on entire tree to turn brown. Wound on tree infected with the nematode will not exude resin.
Scotch pine is particularly susceptible.
There is no control and infested trees should be burned or chipped. The new growth turns brown and the branch is stunted. Black fruiting bodies may be found on the dead needles. The fungus may attack the branches and form cankers. When the canker girdles the stem, the portion of the stem above the canker will die.