Jim Guldin, research ecologist with the FS Southern Research Station (SRS) and project leader of the SRS Upland Forest Ecosystems unit in Monticello, AR, recently announced the results of a pilot study started this summer to quantify the extent of the outbreak. Designed to provide more information about the distribution of the insect, the plot-based study is funded by the Forest Service, with the research conducted by scientists from SRS, the University of Arkansas at Fayetteville, and other agencies.

The red oak borer, an inch-long beetle native to forests in the eastern United States, causes most of its damage while in the larval stage of a two-year life cycle. The larva burrows through the bark of the oak, carving out galleries in the cambium and the heartwood of the tree. The adults emerge from the oval holes they chew in the bark in odd-numbered years. The red oak borer is usually an insignificant pest that oaks can easily fend off, but since 1999, when unusual levels of infestation were found by the Forest Service near Clarksville, AR, the density of red oak borer populations has steadily increased.

"What we found in our preliminary results confirms an explosion of oak borer infestations," said Guldin. "Outbreaks once consisted of five to 10 borers a tree: now we are seeing 1500 a tree. At this level of attack, the insects literally girdle the tree: tens of thousands of trees have died so far."

During the summer of 2002, researchers installed a pilot study on 44 plots, primarily on National Forest land in Arkansas and Oklahoma."Traditional plots established by the Forest Service for forest health monitoring cannot capture the extent of the problem because the plots are too dispersed and not visi
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Contact: Jim Guldin
jguldin@fs.fed.us
870-367-3464 x 13
Southern Research Station - USDA Forest Service
21-Nov-2002