The hemlock woolly adelgid has been found in Walker County, Ga., within the city limits of Chickamauga.
In 2009, Georgia state foresters said the tree-killing bug had spread westward only to about the middle of Murray County.
Now the identification of an infested hemlock in Chickamauga has experts on heightened alert for signs of the bug in Whitfield, Catoosa, Dade and Chattooga counties.
"We have a trip planned later this fall to the Cloudland area (on Lookout Mountain) to survey for the adelgid," said Scott Griffin, the Georgia Forestry Commission's expert on the hemlock woolly adelgid. "This one (in Chickamauga) sounds like it's an isolated pocket of hemlocks."
Tennessee and Georgia forestry experts have said the bugs will spread over the Eastern hemlock in the Southern mountains within the coming decade, carried by wind, deer, birds - even people who brush against infested foliage. The bugs can kill a hemlock in seven to 10 years.
Norman Edwards, University of Georgia extension agent in Walker County, said hemlocks are not native to the valleys of Whitfield, Catoosa and Walker counties, but they often are planted there in home landscapes.
The infested tree in Chickamauga is in a home landscape planting and has been there for a while, Edwards said.
But he urged residents to inspect their trees.
"This is the time of year to treat them - to use what we call a drench around the base of the tree," he said. "We can tell people how to do it."
Edwards said the pesticide in the drench is taken up by the tree roots. Adelgids suck the pesticide along with tree sap and die.
State and federal foresters have treatment plans in the region's parks and national forests, but saving deep-forest hemlocks and private community stands has fallen to homeowners and community groups.
BATTLE THE BUGS
For more information, call:
* Walker County's extension agent at 706-638-2548
* Georgia Forestry Commission at 770-530-3929
* Save Georgia's Hemlocks at 706-429-8010
Experts say that when the forest hemlocks die, the stream banks on which they often grow lose shade. That raises water temperatures in streams that support trout, which need lower water temperatures to survive.
The loss of hemlocks also destroys bird habitat and shade that protects rhododendron and forest wildflowers.
In March, Georgia foresters and a Dahlonega-based volunteer group known as Save Georgia's Hemlocks organized information sessions in Murray County, where the adelgid arrived in 2009.
The alliance also has established a pool of pesticide injectors and instructions to lend to homeowners to protect their hemlocks. Homeowners must buy their own pesticide.