Southern Pine Beetle

The Problem
Southern pine beetles attack most species of pines, but in New Jersey the beetle prefers dense, unmanaged stands of pitch pine. These trees, stressed by drought, disease or soil compaction, become vulnerable to southern pine beetle attacks. Without intervention, southern pine beetle can spread rapidly, affecting thousands of trees.

Tree Effects
When southern pine beetles attack a tree, the tree’s needles turn yellow, then red, and within as little as a month, may become brown. Often an outbreak goes undetected until multiple trees are infected and begin to change color.

Monitoring
New Jersey foresters monitor beetle populations in the spring with traps baited with pheromones and pine turpentine. Pheromones are chemicals produced naturally by female beetles to attract males. Turpentine mimics the scent of stressed or wounded trees. Foresters send trap contents to the US Forest Service who identifies southern pine beetles and their predator, checkered beetles. The US Forest Service reports the ratio of southern pine beetle to checkered beetle to New Jersey foresters. With this information, foresters predict the severity of upcoming infestations.

Management
In one summer, the population of southern pine beetle can increase tenfold, infesting pine trees up to 50 feet per day. Often foresters spot dying trees affected by southern pine beetle while conducting an aerial survey. The foresters inspect the site from the ground for telltale signs of southern pine beetle such as pitch tubes, “S” shaped galleries under the bark and exit holes. To control populations, foresters first cut a 40’-70’ buffer strip around the affected area. Then the foresters chip trees or spray them with insecticide.

Outbreak Prevention
Often crowded, dense stands of trees become susceptible to southern pine beetle and other insects and diseases. To maintain vigor, foresters perform periodical thinnings, which improve growth and health of the forest.