Chestnut blight (Cryphonectria parasitica) is a fungal pathogen of chestnut trees. It is a native of Eastern Asia and was first detected in New York in early 1900's.
This fungus was able to kill the majority of the American Chestnuts in the United States in less than 5 decades. Research is ongoing to develop a blight resistant Chestnut.
For more information about this plant pest, see the CABI data sheet.