I have six Arborvitae planted in a row with about
10 feet betteen trees (Central Maryland). They are about 5 years old and are doing well except for one tree that developed dried needles on one side of the tree and rolled up needles similar in shape and appearance to a cacoon made by butterflies. There does not appear to be anything inside, however.I started spraying the tree with the same thing I am spraying my vineyard (Dithane, Sulphur, Penncop, and Seven). The condition has not gotten worse and possibly it is showing some signs of recovery.
Any idea on what this condition is due to?