MISSISSIPPI GULF COAST — A beetle that made its presence known in Mississippi this summer is threatening the extinction of redbay trees in the state and could harm the future of traditional Cajun cuisine.
The beetle is the redbay ambrosia beetle. It spreads the pathogen that causes Laurel wilt disease in many tree species, including Mississippi’s redbay and sassafras trees. Redbay leaves and file, which is made from sassafras leaves, are used commonly as spices in Cajun dishes such as gumbo.
John Riggins, a Mississippi Agricultural and Forestry Experiment Station forest entomologist, was the first to identify this beetle in Mississippi. Riggins, who is with Mississippi State University’s Department of Entomology and Plant Pathology, found it in redbay trees in the Sandhill Crane Refuge near Gautier in Jackson County. This location on the Mississippi Gulf Coast, identified in July, is 300 miles from the nearest known location in Georgia.
“It only takes one beetle to penetrate the bark of a redbay tree, and that is enough to inoculate the tree and kill it in less than one growing season,” Riggins said.
The beetle and the fungus were both introduced to the United States from their native range in Asia. Since 2002, they have been a problem on the Atlantic seaboard in Florida, Georgia and South Carolina.
There are chemical insecticides that can be used against the beetle and fungicides that can help prevent the disease in trees, but Riggins said these are too expensive and impractical to consider on a large scale. Efforts are being focused on preventing the spread of the beetle and finding out where the infestation came from.
Redbay trees are a common understory component of Mississippi’s coastal forests. They are an important food source for many different species of birds and mammals, which eat the small fruits that the redbay trees produce. Redbays are not an economically important species, but they are sometimes used in cabinet making and woodturning because of their attractive wood grain and coloration.