One of the key symptoms
of pine wilt nematode infestation is the rapid browning
and death of the tree. Fortunately, this generally only
happens to older, sick and declining trees under
environmental stress. These are the types of trees that
are attractive to the sawyers which are borer insects.
Thus, they are the trees that get infected by the
Trees that die of this
problem usually exhibit a bluish stain in the heartwood
of the tree. Unfortunately, this can only be discovered
on a post mortem examination. The stain is not part of
pine wilt but is almost always associated with it.