page_title: Beech bark disease
section_title: History and distribution
hierarchical_section_title: Beech bark disease / History and distribution
caption_attribution_description: Distribution map of beech bark disease
context_page_description: Beech bark disease is a disease that causes mortality and defects in beech trees in the eastern United States, Canada and Europe. In North America, the disease occurs after extensive bark invasion by the beech scale insect, Cryptococcus fagisuga. Through a presently unknown mechanism, excessive feeding by this insect causes two different fungi to produce annual cankers on the bark of the tree. The continuous formation of lesions around the tree eventually girdles it, resulting in canopy death. In Europe, N. coccinea is the primary fungus causing the infection. Infection in European trees occurs in the same manner as it does in North American trees. Though the disease still appears in Europe, it is less serious today than it once was.
context_section_description: Beech bark disease was first documented in Europe in 1849.  At first, it was believed that the scale insect was the main cause of the disease.  It wasn’t until 1914 that the Neonectria fungus was associated with the disease. The first outbreak of beech bark disease in North America appeared in American Beech (Fagus grandifolia) in Nova Scotia around 1920. The disease then started to spread to the south and west. The first case of beech bark disease in the United States was reported in 1929 in Massachusetts. By 2004, the disease had spread as far west as Michigan and as far south as western North Carolina.
caption: Distribution map of American Beech and the beech scale insect.
exif: {}