More sad news (copied across from Gardenweb):
Quoting:
Just a brief update on a new disease killing members of the Lauraceae in the U.S.:
In 2002 an Asian species of ambrosia beetle (Xyleborus glabratus) was found near Port Wentworth, Georgia (near Savannah). It was soon discovered associated with dying Red Bay (Persea borbonia) trees in the vicinity. Closer inspection revealed the presence of a fungus (Raffaelea or Ophiostoma species) similar to the dutch elm disease fungus. The fungus is very aggressive and can kill entire trees in a couple of months. The beetles are the vectors and are likely infecting trees while feeding on twigs on the outer portion of the crown. The fungus rapidly invades the xylem and plugs up the vascular system. Once a tree succombs, large numbers of ambrosia beetles attck them (possibly for brood trees) and are loaded with inoculum to move to the next tree. Symptoms of the disease include wilting, leaves turn brown and do not fall off the trees. Under the bark a dark colored streaking is evident on the wood.
Current distribution includes coastal areas of South Carolina, Georgia and northeast Florida (approximately 31 counties). However, new counties are being detected weekly and the disease is spreading very rapidly via the beetle vectors at a rate of at least 20 miles per year. It is likely that humans are aiding in its dispersal by moving firewood of infected trees to new areas.
The host range is still being determined, but all members of the Lauraceae seem susceptible. So far it has been found in Persea, Sassafras, Lindera and Litsea in the wild.
The impact of this disease is huge. Most stands surveyed have at least 95% mortality after the disease moves through. Unfortunately it looks like red bay will be extirpated from most areas. Time will tell for other species.
I am working with the U.S. Forest Service and others to see if the very few trees remaining have any resistance to the disease. Many other studies are underway to try to reduce the impact of this disaster.
If you suspect the presence of this disease, please contact your county extension agent or let me know and I can give you advice on who to report it to.
I will keep you posted.
Jason Smith, forest pathologist, University of Florida
