Its presence has been known since the 1880's where in Southern California it destroyed 35,000 acres of vineyards. At that time the disease was known as Anaheim Disease, Mysterious Disease and the California Vine Disease. It was eventually named for N. B. Pierce, who extensively studied the disease. The bacteria, X. fastidiosa , is limited to the xylem or water conducting vessels of plants. Symptoms begin to develop about mid-summer as the bacteria blocks these vessels and a drying or scorching of the leaves is seen.
Leaves become chlorotic along the outer edges or adjacent to the dead tissue.
The drying or scorching of the leaf continues for a few days to weeks until the leaf eventually falls, usually leaving the petiole attached to the cane. Petioles gradually die back and fall. Maturing canes that turn tan will have green islands along the infected portions. When new growth occurs on infected canes it can be delayed and is usually stunted. Leaves on stunted shoots can have a yellow mottling between the major veins.