Invading bugs ravage our forests

In Georgia’s rugged mountain forests and its lush maritime woods on the coast, ecological tragedies of great consequence are unfolding —- alarming die-offs of native trees from exotic insect pests.

On the coast, it is the red bay tree —- and possibly the sassafras —- that’s succumbing. Driving around Jekyll Island the other day, I saw scores of red bays dead or dying. I saw no healthy ones. The same situation is true for red bays in other maritime forests all along the Southeast coast. Killing them —- and threatening them with extinction —- is a relentless disease called laurel wilt.

Some reports indicate that the malady also may be spreading to our beloved sassafras trees, which are kin to red bays.

The disease is caused by a fungus spread by the exotic red bay ambrosia beetle (Xyleborus glabratus), a native of Asia. The beetle likely entered the country in wood packing material with cargo imported at Port Wentworth, Ga. Red bays began dying in Georgia and South Carolina in 2003.

“All of Georgia’s coastal counties now have confirmed laurel wilt, and the disease is moving northward in South Carolina, southward in Florida, and inland at an alarming rate,” said James Johnson, a tree disease expert with the Georgia Forestry Commission.

No known treatment exists, he notes. Landowners, loggers and others are asked to leave dead red bay trees in the woods and not salvage them for logs, chips or firewood.

Red bays are native to the Coastal Plain region from Virginia to eastern Texas. They are ecologically and culturally important, although of minor commercial timber value. Red bay trees provide fruit for songbirds, turkeys and quails. Deer and black bears browse on the foliage and fruits. The caterpillars of the palamedes swallowtail butterfly require red bay leaves for development.

More information: www.state.sc.us/forest/idwilt.pdf.

Mountain trees

In North Georgia’s mountains —- and throughout much of the Southern Appalachians —- it is the magnificent hemlock that’s dying by the tens of thousands. The cause is a tiny, exotic, aphidlike insect known as the hemlock wooly adelgid, also a native of Asia. It sucks the sap at the base of hemlock needles, which die and fall off. The tree then starves to death.

Hardly any area of the 750,000-acre Chattahoochee National Forest is untouched by the voracious pest. Dead and dying hemlocks —- large and small —- are now common sights along mountain streams, slopes and trails. Scientists say the hemlock, a major component of Southern Appalachian forests, could go the way of another once-common forest tree, the American chestnut, which was virtually wiped out by an exotic blight during the first half of the last century and has never recovered.

A sliver of good news is that special chemical treatments done by trained arborists can help hemlocks withstand adelgid infestations. The treatment is helping save some hemlocks in homeowners’ yards and at some forest campgrounds.

But for the vast majority of hemlocks in the forest, the treatment is impractical. About the only hope —- slim at best —- for the forest hemlocks is imported beetles that prey on the adelgid. Three Georgia institutions —- the University of Georgia, Young Harris College and North Georgia State College and University —- are raising the beetles in special laboratories for release into the forest. But funding is critical. The Georgia ForestWatch organization (www.gafw.org.) is trying to raise funds for the labs.

Another group, the Lumpkin Coalition, is holding its annual HemlockFest next weekend (Nov. 7-9) in Dahlonega to raise funds for the labs. For information about the festival: www.lumpkincoalition.org/HemlockFest.htm.

Fall colors

On a happier note, I was at a Georgia ForestWatch retreat in the Cohutta Mountains near Chatsworth last weekend, and the leaves of oaks, hickories, maples and other hardwoods were just taking on their glorious fall colors —- especially orange, which tends to dominate this time of year. Leaf color should be at its peak this weekend provided a hard frost doesn’t hit the leaves.

In fact, said Dr. Kim Coder, a University of Georgia tree expert, peak color time about 18 years ago was around Oct. 26. Now, it comes 10 days later, probably because of regional climate change. Warmer days and nights have affected when the leaves change colors.

Bird help

Want to help grassland birds such as sparrows? Then help collect native grass seeds for grassland restoration next weekend at Panola Mountain and Sprewell Bluff state parks. To participate, contact project coordinator Charlie Muise at cmmbird@yahoo.com.

In the sky

The Taurid meteor shower is visible for the next few nights with a peak of 15 meteors per hour on Tuesday night, says David Dundee, astronomer with the Northwest Georgia Science Museum. Look to the east from about midnight to dawn.

The moon will be first quarter on Wednesday, high in the south at sunset. Mercury is low in the east just before sunrise. Venus shines brightly in the west just after sunset and sets in the west about two hours later. Jupiter is high in the southwest just after dark and sets in the west before midnight. Jupiter appears near the moon early Monday evening. Saturn rises out of the east shortly before sunrise.

seabrk@comcast.net