Larvae chew curved or S-shaped galleries under the bark in the inner bark and cambium layer, and can girdle and kill the tree. In addition, the beetles introduce a fungus that can be lethal to the tree. Southern pine beetles prefer shortleaf, loblolly, Virginia, and pitch pines. The beetles usually are attracted to weakened mature trees, those more than 15 years old and with a trunk diameter of less than 6 inches. During outbreaks, they attack trees that appear to be healthy and vigorous.
Infestations usually begin on the mid-trunk area and then expand up and down the length of the tree.
Resistant species such as slash, longleaf, and eastern white pine, have a high resin exudate that provides an effective defensive mechanism against the beetle. However, even resistant trees can be attacked successfully when the beetles are very abundant. Management of Infestations Southern pine beetles often attack stressed and injured trees in older-aged, dense stands, so cultural practices that promote healthy trees will reduce the frequency and severity of infestations. During outbreaks, avoid pruning and other activities which produce odors that attract dispersing beetles. An insecticide may be sprayed onto the trunk of landscape pines to protect them when there is an active SPB infestation in the area.