Live Oaks, can get Oak Wilt
by way of root transmission from another Live Oak, or from
the sap feeding, Nitidulide beetle. This insect would first have to
have fed from a tree with an infected fungal mat.
A fungal spore can stick to its body, then be carried to the next
tree that the insect feeds upon. Red Oaks are the most common tree
to produce this infected fungal mat.
Insect transmission does not occur from Live Oak to Live
Oak as Live Oaks are
incapable of producing the infected fungal mat and fungal spore.
When Oak Wilt travels through the grafted root system of Live
Oaks, it is at a rate of about 75 feet per year. Spread at a rate of
150 feet per year has been documented.
Spanish/Red Oaks primarily get
Oak Wilt by insect transfer. Spanish/Red Oaks do not develop
grafted root systems. Furthermore, Spanish/Red Oaks are one of the
few trees known to produce the infected fungal mat and fungal
spore, that can be transported by way of sap feeding beetles. This
infected fungal mat most commonly forms in mild temperatures, for
the first year following the trees death from Oak Wilt.
Spanish/Red Oaks can not be salvaged once they have contracted the
disease. They should be removed immediately upon decline.
Most Oaks develop mechanical problems
which cause self inflicted wounding.
includes interlocking limbs, branches rubbing on roofs or other
structures and trees
growing up into and through the crown of susceptible Oaks. This
type of abrasive wounding, will never heal, and will flow sap year
around. The flow will be heaviest during peak insect and fungal
mat formation periods. All pruning cuts made by man, even large or
incompetent cuts, will stop flowing sap within a couple of hours.
If these wounds are properly treated with pruning paint, there
will be no sap flow at all and the wound will be unattractive to
the insect. Therefore, properly
pruned Oaks are less likely to become infected by sap feeding
1. Trees that need to be pruned,
should be pruned, by a professional Arborist, as soon as possible.
This will significantly reduce the possibility of Oak Wilt infection
by insect vector.
2. Needless to say, trees that don't need to be pruned, should
not be pruned.
3. When pruning
trees susceptible to insect transmission of any disease, a non-phytotoxic
wound sealer should always be used.
Again, call us, we are here to help. We have professional
Arborists to help you make that determination.