By David A. Farrell, Item Staff Writer
The Picayune Item
STARKVILLE, Miss. —
A Mississippi State University entomologist says preliminary investigations have shown that the Chinese ambrosia beetle, which attacks and kills redbay and sassafras trees, has spread into eastern Harrison County in Mississippi, and Marengo and Mobile counties in Alabama, after first being detected about three years ago in portions of Jackson County along the Pascagoula River.
Marengo is just east of Meridian. Mobile County, which includes the City of Mobile, butts up against the Jackson County and Mississippi state line in southeastern Mississippi.
“I want to reiterate that these findings are preliminary, but it seems to indicate some bad news,” said Dr. John Riggins, an MSU associate professor, who is conducting several studies on the beetle with federal grants.
He added, “We have captured some beetles in traps over the Harrison-Jackson county line in Harrison County, and we have found some symptomatic trees. These findings in Harrison County are in the process of being confirmed, however.”
Riggins said confirmation has been obtained that the beetle is now in Mobile County and in Marengo County in Alabama. He said that Morengo is the first place in the United States where it has been confirmed that the beetle can survive in areas exclusive to sassafras. “That is a disturbing finding, since sassafras stands stretch all the way to Canada,” he said.
He said that the Marengo findings indicated that the beetle, believed to have been brought into the U.S. through a Georgia port in wood packaging material from China, can survive not only on redbay but on sassafras stands alone. The beetle was first trapped near Port Wentworth, Ga., in 2002, and was later connected to the death of redbay trees in a 40-mile radius of the original trap site.
“That fact, that it can survive just on sassafras, too, is particularly disturbing because sassafras trees stretch all the way up into Canada,” said Riggins. He said studies are showing the beetle can survive, too, in the cold northern winters, which is more bad news. “We were hoping it could not handle the northern cold winters,” said Riggins.
He said his study has shown also that the beetle infestation has collateral impacts. He said that in areas where infestations were heavy, the palmetto butterfly, which uses the redbay as a host in its life cycle, showed a 10-fold decrease in numbers in areas.
“Of course, these are estimates,” said Riggins, “but they are based on scientific surveys, and always when you disturb something in nature, like the redbay and sassafras trees, you disturb something else that depends upon them, too.”
Riggins said he has applied for additional grants to increase his study and staff, but said that right now “my funding is inadequate to mount a full-scale attack on this problem.” Federal funds have been funneled through the State Forestry Commission to Riggins.
Riggins said he did not want to “overstate” the problem, but added that he believes the Eastern and Southeastern U.S. faces a major ecological threat to the redbay and sassafras tree population, unless adequate funding to get a handle on the exact nature of the problem and possible remedies to save the trees, which have for thousands of years been a basic species in the Southeastern forests. His studies have been going on for about three years.
The possible impact of the beetle on the redbay and sassafras trees has been compared to the destruction of American chestnut tree populations, which were destroyed by a disease from China that invaded the U.S. Ecologists have called the chestnut tree destruction, which ran from about 1900 to 1950, the greatest ecological disaster in U.S. history. Animals and humans alike ate the chestnut that fell to the ground in fall.
Riggins said that studies on the beetle, trapped in Jackson County, shows that it is the same species that killed vast swaths of redbay and sassafras on the Southeastern Atlantic seaboard, and that researchers believe it was brought into Jackson County in a load of firewood, or by a woodworker transporting some logs to the Gulf Coast.
When the studies were originally begun in 2010, Riggins said researchers were trying to determine in what direction the beetle might be moving from its original Gulf Coast site in Jackson County. “I am sorry to say the research so far is turning up some evidence that is quite disturbing,” he said.
Researchers were amazed that the beetle would show up in Jackson County only about three-to-five years after being detected along the Atlantic seaboard. Investigators expected it would take 20 years to spread to the Mississippi Gulf Coast, but the beetle made the jump in less than five.
The beetle also has infested large areas in South Carolina and Florida, besides its original site in Georgia. In Florida it has also threatened the avocado crop. Researchers say that in Florida it has been found in the following counties: Alachua, Baker, Bradford, Brevard, Citrus, Clay, Columbia, Flagler, Indian River, Marion, Martin, Nassau, Okeechobee, Osceola, Putnam, St. Johns, St. Luicie, Suwannee, Union and Volusia, according to a Mississippi Forestry Commission technical bulletin.
The beetle does not actually eat a tree’s wood. It injects a fungus, which grows, clogs the tree’s pores and kills it. The beetle’s young live off the fungus. When a beetle bores into a tree, the tree dies in about two weeks. First the leaves wilt, and researchers have named the infestation the “laurel wilt” — bay trees are members of the laurel family — disease because of that characteristic, but it is caused by the beetle. It only takes one beetle to kill a tree.
Right now there is no effective pesticide that can be used to combat the infestation, and researchers are looking for an antidote to the beetle and its destructive fungus.
Redbay and sassafras trees are highly important and have played a part in Southern culture for hundreds of years, and part of the ecological underpinning of Southern forests for thousands. Redbay tree leaves are used as seasoning in Cajun dishes. The wood is also used in cabinet making and wood-turning because of its beautiful grain. It is also host to three different species of nesting butterflies.
The sassafras was once used as a base for root beer and the roots are still used to make sassafras tea in the Spring, an historic drink that once was a staple, even as a medicinal drink. Old-timers said sassafras tea “cleaned the blood” and they drank it every Spring when the sap flowed. Crumbled sassafras leaves are the filet in Cajun filet gumbo. Sassafras trees also produce brilliant displays as the leaves turn to fall colors and its wood is often used in cabinetry and for making piano sound boards.