Oak Wilt - Why is it spreading?

1.  The main reason most don't know that this disease even exists or if they do they don't realize it is in our area.  There are very few spreading the word about what is causing the demise of trees due to disease, and even less that have solutions to help mitigate the problem.

2.  Misinformation is another reason the spread picks up speed.  A few of the misperceptions that are out there are that white oaks are not susceptible to oak wilt, this is not true.  Although the infection takes a different route than in other species it is a major problem among this group of trees.  Another, is that the disease only spreads to nearby trees through root grafts, so if trees are not close together they are not at risk.  This ignores the fact that the nitidulid beetle carries the fungal spores farther distances to trees that are not in close proximity for root grafts.  A common misnomer is that an infected tree was removed so other nearby trees are not at risk.  Even after removal, oak wilt is still present in the stump, infected branches (unless disposed of properly), and in the roots (which may be grafted).  In addition, the chances for reintroduction of spores is extremely high, especially in an area where oak wilt infection has already occurred.

3.  Misdiagnosis is an interesting reason for not treating.  This is peculiar as diagnosis is not necessary for preventative measures.  I have seen where tree owners decline to treat because symptoms may be caused by other factors.  Although it is true that the symptoms can be similar to other underlying conditions, the best is to treat before oak wilt infection occurs.  Sending out samples for testing is not very practical as the conditions that need to be met to keep a culture testable are very stringent.  When the culture is not kept at a certain temp or is kept for too long before testing, false negatives are often the result.  It is just as important to address other causes which can be affecting the health of the tree.