SOUTHERN PINE BEETLE EPIDEMIC HITS STATE
Tiny beetles about the size of a grain of rice are silently killing thousands of acres of Alabama forests. Southern pine beetles thrive in the high summer temperatures, spreading through forests in many areas of the state already stressed by drought.
The trademark brown spots, often located amid lush green trees, may be the first indication that a property owner has a "beetle spot." The year 2000 is expected to be a record year in Southern pine beetle population. Recent reports from the Alabama Forestry Commission indicate that 53 counties have been infested by beetles, with the worst areas located in Bibb, Tuscaloosa, Jefferson and Shelby counties. And officials predict the problem will only get worse until cooler weather arrives.
"The Southern pine beetle is the most destructive insect pest of pine in the southern United States," said Steve Guy, director of the Federation's Forestry Division. "Southern pine beetles aren't new to the state, but the outbreak does appear to be headed for near epidemic proportions this year."
The insect is native to North America and lives predominantly in the inner bark of pine trees. Trees attacked by Southern pine beetles often exhibit hundreds of resin masses, called pitch tubes, on the outer tree bark. The insects feed on phloem tissue (just under the bark) where they construct winding S-shaped or serpentine galleries. These galleries can girdle a tree, causing its death. Southern pine beetles also carry blue-stain fungi that damages the trees' tissue and blocks water flow within the tree. Beetle spots can expand at rates of up to 50 feet per day and uncontrolled infestations may grow to thousands of acres in size.
The best way to detect Southern pine beetles is to remove sections of bark from trees with fading (yellow) foliage or from trees with bark just starting to loosen. Look for the winding, S-shaped tunnels or galleries made by the adult beetles. The tunnels are filled with sawdust-like material left behind by feeding adult beetles. In pines just coming under attack, galleries are not yet present. The first symptom in this case will usually be the pitch tubes in bark crevices, or sawdust at the base of the tree. But it should be noted that pitch tubes alone are not reliable indicators because other bark beetles also leave them.The Southern pine beetle does not attack hardwood species such as oak and hickory.
Even if the beetle spot is small, the trees must be cut down, plus a buffer area around the site is cut to prevent the beetles from spreading. Cutting smaller areas barely covers the cost of having the trees removed, plus forcing timber producers to sell before the trees reach maturity diminishes the return on their investment. Beetle trees also are less valuable because the blue stain fungus discolors the wood, resulting in poor-quality pulp.