Wednesday, November 18, 2009
Red Bay Trees Losing Battle.
Mortality of red bay trees (Persea borbonia) in coastal locations in South Carolina, Georgia and Florida is spreading rapidly, resulting in the death of nearly all red bays and sassafras trees in the infected areas.
The cause of the disease is a fungus (Ophiostoma sp.) vectored by an Asian ambrosia beetle (Xyleborus glabratus). Both the beetle and fungus are recent introductions into the United States. At the present time, there is no known method to halt the spread of this disease. The Beetle was first discovered in palets at Port Wentworth, Savannah, back in 2003 and probably came from China or Thailand.
Just before Steve and myself reached Cumberland Island earlier this month, rangers and forestry workers had been out on the island collecting Red Bay seeds for the Federal Seed Bank. This is not a good sign as is means there is nothing that can be done to stop the spread of this deadly disease.
Red bay trees extend from Virginia to Louisiana on the coastal plain. A member of the laurel (Lauraceae) family, it is closely related to swamp bays and silk bays.Also in the Lauraceae family are: 1. pondspice (Litsea aestivalis); 2. avocados; 3. sassafras; and 4. pondberry or southern spicebush (Lindera melissifolia), a federally endangered species. Currently red bays and sassafras are confirmed to be susceptible to this wilt disease. It is unclear if other members of the laurel family can serve as hosts to this disease. Since it is suspected that several members of the family may be impacted, the proposed name for the disease is “Laurel Wilt Disease”.
Red bays have limited commercial use. The wood is sometimes used in cabinetry and boat building and the trees are occasionally used in landscaping. The seeds of red bay are eaten by turkeys, quail, deer, songbirds and bears. Leaves are used in Southern cooking to flavor gumbos.
Red bays are host plants to three butterflies: palamedes, Schaus and spicebush swallowtails. The palamedes is obligate to the red bay as the eggs are laid on the leaves and the emerging caterpillar eats the leaves.
The disease continues to spread unabated.
Summary prepared by: Richard M. Bryant