The southern pine beetle (SPB), Dendroctonus frontalis, is a minute (3 mm), invasive insect that is native to southeastern states and is the most destructive insect pest of their forests. Its range extends from New Jersey to Florida to Texas to Illinois. The SPB must kill its host pines to reproduce, and attacks trees en masse. The SPB causes significant and rapid economic losses in all forest types, including traditional forests, urban forests, watersheds and viewsheds, and negatively impacts habitat for endangered species and recreational areas. In addition, human safety and property are threatened by SPB-killed trees, which may be susceptible to fire and whose removal costs usually exceed the tree's value.
Three complimentary phases of forest management are used to reduce losses to the SPB: prevention of attacks, prediction of where outbreaks will occur, and suppression of populations that have reached pest status. Prevention relies on forest management practices, like thinning, to promote vigorous trees and healthy forests that are consequently inhospitable to SPB. Prediction of SPB damage is accomplished through annual monitoring of population levels with traps, and the identification of forests that are most likely to be attacked. These forests can then be monitored more closely or scheduled for management to reduce their susceptibility. Suppression relies primarily on the removal of infested and nearby trees. Acting together, these activities do not always prevent outbreaks but rather work to reduce their size, frequency, duration, and impacts.
The SPB sometimes exists at low (endemic) population levels where it can be scarcely found, and other times at high, epidemic levels, where it causes rapid, unpredictable and substantial damage to forests. At endemic population levels, healthy pines are usually able to thwart beetle entry via oozing resin and the formation of “pitch tubes” at the beetle attack site. This kills the beetle and saves the tree. The SPB may subsist by killing decrepit trees like those struck by lightning. However, at outbreak levels, even healthy, resistant trees are killed. The last widespread outbreak occurred in the early 2000's and resulted in an estimated $1.5 billion dollars of economic damage. Today’s forests are generally denser and older, while at the same time urbanization and land use priorities, such as recreation and protection of water resources, have increased their value. Similar to the evolving impacts of wildfire, these factors work in concert to make SPB a greater threat than ever.
For more information on the biology, ecology and management of the southern pine beetle, as well as numerous other forest insects, diseases and plants, please contact Doug Streett, Project Leader of the Insects, Diseases, and Invasive Plants (IDIP) Research Work Unit in Pineville, LA or visit the IDIP website.
Find research publications about the southern pine beetle on Treesearch.