Featured Research

from universities, journals, and other organizations

Laurel Wilt Of Redbay And Sassafras: Will Avocados Be Next?

Date:
April 7, 2008
Source:
Southern Research Station - USDA Forest Service
Summary:
Scientists have provided the first description of a fungus responsible for the wilt of redbay trees along the coasts of South Carolina, Georgia and Florida. Plant pathologists have now provided results from their assessment of the fungus, the beetle that carries it, and their combined effect on redbay and other members of the laurel family, including sassafras, spicebush and avocado.

The large redbay shown next to the Horton House ruins on Jekyll Island, GA was once considered one of the largest redbays in the United States. Killed by laurel wilt, it was cut down in November 2007.
Credit: Image courtesy of Southern Research Station - USDA Forest Service

Scientists with the USDA Forest Service Southern Research Station (SRS), Iowa State University, and the Florida Division of Forestry have provided the first description of a fungus responsible for the wilt of redbay trees along the coasts of South Carolina, Georgia, and Florida.

Related Articles


In the February issue of Plant Disease, SRS plant pathologist Stephen Fraedrich and fellow researchers provide results from their assessment of the fungus, the beetle that carries it, and their combined effect on redbay and other members of the laurel family, including sassafras, spicebush, and avocado.

Extensive mortality of redbay, an attractive evergreen tree common along the coasts of the southeastern United States, has been observed in South Carolina and Georgia since 2003. Though the wilt was at first attributed to drought, the cause was soon found to be a fungal pathogen and the exotic redbay ambrosia beetle, Xyleborus glabratus, a native to Southeast Asia that was first found in the area in 2002. Many ambrosia beetles carry species of fungi as food for their larvae; a previously undescribed fungus in the genus Raffaelea is a fungal symbiont of this ambrosia beetle.

To determine if the fungus was the cause of the wilt, Fraedrich and his colleagues inoculated redbay trees and containerized seedlings with the Raffaelea fungus; the plants died within 5 to 12 weeks. To connect fungus and beetle, they also exposed redbay seedlings to X. glabratus beetles; the ambrosia beetles tunneled into almost all of the plants, causing 70 percent of them to die. The researchers found the fungus in 91 percent of the beetle-attacked plants.

"These experiments showed that the Raffaelea species we isolated from wilted trees and from the redbay ambrosia beetle is the cause of redbay wilt," says Fraedrich. "The fungus, which is routinely isolated from the heads of X. glabratus ambrosia beetles, is apparently introduced into healthy redbay during beetle attacks on stems and branches."

Redbays are common along Southeastern coast, and both residents and visitors are disturbed by the massive mortality. Deer browse on the evergreen foliage of the tree, and the fruit is eaten by songbirds, wild turkeys, and other animals. Redbay is also the primary host for the larvae of the palamedes swallowtail butterfly. But it’s not just the redbays that plant pathologists are worried about.

"The fungus we isolated has also been associated with the death of other trees in the laurel family, and the Raffaelea sp. has been isolated from wilted sassafras, pondberry and pondspice," says Fraedrich. "Our inoculation studies have shown that the fungus is deadly to these species as well as to spicebush, and avocado, but not to red maple."

The researchers concluded that there is reason to be concerned about the spread of the wilt to other members of the laurel family, which are common components in forests across the United States and other areas of the Americas. Recent studies have shown that California laurel, a West Coast species in the Lauraceae, is also susceptible to laurel wilt.

"We are also very concerned about avocado, a species indigenous to Central America which is grown commercially in Florida and alifornia," says Fraedrich. "Our evaluation of avocado indicates that it is also susceptible to laurel wilt, and the wilt has been found recently in avocado trees growing in a residential area of Jacksonville, Florida."


Story Source:

The above story is based on materials provided by Southern Research Station - USDA Forest Service. Note: Materials may be edited for content and length.


Cite This Page:

Southern Research Station - USDA Forest Service. "Laurel Wilt Of Redbay And Sassafras: Will Avocados Be Next?." ScienceDaily. ScienceDaily, 7 April 2008. <www.sciencedaily.com/releases/2008/04/080402151409.htm>.
Southern Research Station - USDA Forest Service. (2008, April 7). Laurel Wilt Of Redbay And Sassafras: Will Avocados Be Next?. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2008/04/080402151409.htm
Southern Research Station - USDA Forest Service. "Laurel Wilt Of Redbay And Sassafras: Will Avocados Be Next?." ScienceDaily. www.sciencedaily.com/releases/2008/04/080402151409.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins