Where TCD has been found
Thousand cankers disease occurs in nine Western and five Eastern States (shaded gray); the year in which the disease was confirmed is noted. Since 2010, TCD has been confirmed in Pennsylvania, Tennessee, and Virginia, whereas the beetle alone and the pathogen alone have been found in Ohio and North Carolina, respectively (denoted with asterisks).
The map shows the native ranges of eastern black walnut (dark green) and four western black walnut species (blue). Eastern black walnut is widely planted in the West, but this map does not depict these western locations.