Near this site in
anthracnose disease was observed on flowering dogwoods (Cornus
It spread rapidly, appearing only two after first being discovered in
York and Connecticut. Earlier (1976) the symptoms of the disease had
seen on another native dogwood species, Cornus nuttallii,in
state. Since 2002 the has been reported in Germany and Italy in nursery
stock. Discula destructiva was described relatively recently
from near Camp David, Maryland in the Catoctin Mountains as the fungus
causing the disease. Within ten years of its first reported infection,
89% of the dogwoods in Maryland were dead and the rest were infected.
infected areas in the United States, 30-40% of dogwood trees have died.
A study in Great Smoky Mountains National Park showed that dogwood
may be controlled by controlled burning. The geographical origin of Discula
destructiva is unknown, but the pattern of sudden and agressive
of the disease at at least two distant localities in the USA, indicates
the fungus was introduced from an exotic site. In fact genetic evidence
suggests that at least two introductions occurred at about the same
in the western and eastern USA. Without careful monitoring, increased
and travel will result in continued introducion of invasive microbial
of plant and animal diseases.
--U. D. Nguyen
and M. Blackwell