160A Zillicoa St. , Asheville, NC 28802, 
(828) 257- 4200, Fax (828) 257-4263

FOR IMMEDIATE RELEASE:        Contact: Forester, Ed Brown (828) 257-4248

January 5, 2000                                                          
                         

Southern pine beetle attacks western North Carolina forests      

An insect the size of a grain of rice is attacking forests and leaving a trail of dying pines across most of North Carolina’s western counties, including Nantahala and Pisgah national forests.

"The southern pine beetle, Dendroctonus frontalis, poses the largest threat to pine trees in the South. During outbreaks, beetles make a mass attack and kill even the most vigorous and healthy trees. Under these conditions, infestations can involve large numbers of trees over hundreds of acres," said Ed Brown, forester for the National Forests in North Carolina in Asheville. Indigenous to the South, the southern pine beetles increase in number where trees are old or stressed by crowded growing conditions and drought.

"Following dry conditions in the late 1980’s, the last serious outbreak in North Carolina occurred on the Nantahala and Pisgah national forests in 1989 and 1990," said the forester. "Drought conditions experienced in western North Carolina for the past 2 years probably contributed to the increased southern pine beetle activity we are now experiencing."

According to Wes Nettleton, entomologist with the U.S. Forest Service in Atlanta, "The insect has many natural enemies that may directly or indirectly affect its development. These natural enemies help to maintain low beetle population levels during normal growing conditions. But with increasing age, crowded growing conditions and drought, beetles build up to outbreak levels and the natural enemies cannot respond quickly enough to control individual infestations."

Southern pine beetles kill a tree by boring through the bark to the first layers of wood, which are the primary transport system for moisture and nutrients in the tree. Once inside, large numbers of beetles excavate galleries or small tunnels to lay eggs, which hatch and develop. This process destroys the nutrient and moisture transportation system within the tree, and it eventually dies.

The defense mechanism for the tree is to "pitch out" the attacking beetle with resin or pitch flow. However, when the tree is old or under stress from crowded growing conditions or from drought, the tree does not have the ability to produce enough resin to "pitch out" the insect.

As the broods or offspring develop and mature, they emerge from the host tree and attack adjacent trees, which increases the size of this infestation or starts new infestations. Infestations are detected when groups of pines have individual trees with yellow, red and brown needles.

The most common method of suppressing or controlling the spread of infestations is to remove trees that have active beetles as well as a small buffer of healthy trees to remove immediate suitable host trees for emerging adults.

The U.S. Forest Service is currently assessing southern pine beetle infestations on the Nantahala and Pisgah national forests. "We will evaluate each southern pine beetle infestation to determine if control measures are needed to protect visitors or prevent the loss of valuable forest," said Brown. "Due to management objectives for areas such as wilderness and inaccessibility, control measures may not be possible in some national forest areas."

For more information, contact the National Forests in North Carolina at 828-257-4200.

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