Gypsy Moth Suppression Program

Jeremy Lowell - Program Coordinator
Carter Rogers - Assistant Program Coordinator

Bay County Building
515 Center Avenue, Suite 503
Bay City, Michigan 48708-5941
Voice: (989) 895-4195

Beech Bark Disease (BBD)



Beech Bark Disease (BBD) is a disease that causes mortality and defects in American beech trees in the eastern United States. BBD is caused by a fungal pathogen that doesn't attack trees until they have been extensively infested with a non-native scale insect.The sap feeding scale insects, in combination with the Neonectria fungus, causes BBD.  American beech trees first become infested with a non-native beech scale insect in the 1980s, and was first discovered in Michigan in 2000.


The scale insects which are covered in waxy white wool can turn infested portions of the tree almost completely white.


The fungus affects the tree’s health by blocking the flow of sap and killing the wood of the tree. Affected trees then decline in health and will eventually die. Some infected beech trees will break during heavy winds before completely dying. This condition is known as “beech snap”.

Out of an estimated 32 million American beech trees in Michigan, about 2.5 million trees have been killed by BBD to date.  Much of the loss has occurred in the eastern Upper Peninsula. Newly infested areas of beech forests with the disease are reported in the Lower Peninsula every year. Mortality of the trees occurs three to six years after scales first infest an area. The larger the beech tree the more susceptible it will be to the disease. Scale infested trees with apparently healthy crowns can become a risk due to beech snap.

You can help prevent the spread of beech bark disease by not moving beech firewood or logs from infested areas to areas yet to be affected. Controlling the natural spread of BBD is not yet feasible due to the fungus and scale insects being so easily moved by the wind and animals.

If you notice signs of the scale insects occurring on beech trees in your area, watch for areas with resistant trees, and report all your findings to the Bay County Gypsy Moth Suppression Program Staff at or call 989-895-4195.

For more information about Beech Bark Disease (BBD) Please check out the links below: