ash genetics -- 001

ash genetics -- 001

ash tree death spiral

This sequence of photos shows what happens to green ash trees over several years from the time they are infested by emerald ash borers. The death spiral occurs after adult beetles lay eggs on their bark. When the eggs hatch, the larvae bore into the bark and feed on the transportation tissues of the tree. This disrupts the movement of nutrients and water within the tree, girdling it and causing death.

IMAGE: John Carlson/Penn State