Bugs at War To Save Pine Trees

Friday, January 12th 2001, 12:00 am

By: News On 6

PIKEVILLE, Ky. (AP) â€” Pine beetles are devouring trees throughout the South, prompting a bug war with their natural predators that agriculture officials are counting on to halt the invasion.

The southern pine beetles have destroyed about half the pines in the Appalachian mountains of Kentucky, Tennessee and North Carolina. Agriculture officials hope a ground force of checkered beetles coupled with aerial assaults by tiny wasps will fend off the infestation.

``Southern pine beetles are the most devastating forest insects in the South,'' said Rusty Rhea, an entomologist for the U.S. Department of Agriculture in Asheville, N.C.

The insects chew their way into loblolly, yellow and Virginia pine trees to lay their eggs. As those eggs hatch, the larvae chew their way along in the trunk, killing the tree. When the larvae reach insect stage, they fly to another tree and repeat the damage.

Foresters say pine seedlings will grow back in place of larger trees that are damaged, but that does little to satisfy Judy Brimm, who has lost about 300 trees around her home near London, Ky.

``This spring, I didn't see anything wrong with the trees,'' Brimm said. ``Now they're turning brown and the bark is falling off because of the southern pine beetles. You don't know they're there until it's too late.''

The U.S. Forest Service spent $750,000 to combat the beetles last year with little success. That amount is expected to be higher this year.

Because of federal environmental regulations, no pesticides are available to effectively control the pests in forests, said Paul Finke, who heads pine beetle suppression efforts in the Daniel Boone National Forest in eastern Kentucky.

Heavy infestations also have been reported in the Deep South, causing $40 million to $50 million in damage in Alabama alone, Rhea said. Because pines are outnumbered by hardwoods in the affected Appalachian region, the financial impact has not been as great as in the Deep South.

Foresters won't know until spring how much impact this winter's cold temperatures will have on the infestation. Rhea said temperatures would need to fall into the single digits for several weeks to wipe out the population of the rice-sized insects.

Short of that, the checkered beetle, named for the pattern on its back, and the wasps are the best hope, Rhea said. The checkered beetle eats the pine beetles as well as their eggs and larvae, while the wasps kill the pests by laying eggs inside their bodies.

The natural predators' numbers haven't been sufficient to control the pine beetles, but that is apt to change, possibly this summer, he said.

``It's kind of a catch-up game by the checkered beetle. After two to three years, they reach the level that they can impact the population of southern pine beetles,'' Rhea said.

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On the Net:

U.S. Agriculture Department: http://www.usda.gov

Daniel Boone National Forest: http://www.r8web.com/boone