The fungus, Geosmithia morbida, causes Thousand Cankers Disease in trees and was discovered on small weevils in a black walnut plantation in Yellowwood State Forest in Brown County.
It is estimated there are 31.5 million walnut trees in Indiana. Based on the dollar value of wood produced, the black walnut tree is the most valuable. Approximately 17.7 million board feet of black walnut is annually harvested in Indiana with a value of $21.4 million. If all forest walnuts were infested with TCD it would represent a $1.7 billion dollar loss.
The plantation in Brown County has been quarantined under the orders of the director of DNR Division of Entomology and Plant Pathology, Phil Marshall. The quarantine only restricts the movement of black walnut trees out of the plantation. Marshall claims the trees currently show no symptoms of TCD but if the status changes, the trees will immediately be cut and destroyed to prevent spread out of the plantation.
To get more information about TCD or to report a suspicion of an infestation in your own foliage contact the DNR toll free at 1-866-663-9684 or visit the website.