Beetle Attacking Local Pitch Pines
The Southern Pine Beetle (Dendroctonus frontalis) is an insect that has typically been endemic to the southern United States. However, recent climatic warming conditions have allowed this insect to travel further and further north along the east coast of the U.S. The Southern Pine Beetle (SPB) hit the NY, NJ area hard about a decade ago in 2014. Our warming climate and mild winters have encouraged its spread northward. Its damage is documented on Martha's Vineyard, and the insect has likely landed on Cape Cod. At this point, it is a matter of when will we see these insects infesting our pitch pines, not if. SPB is known to attack pitch, red, and jack pine trees. It can kill trees in a matter of weeks and decimate a dense strand of pitch pines in short order.
Females disperse from brood trees and seek out and attack new host trees in late spring and early summer. SPB chews into the Phloem tissue and releases a pheromone that, when combined with the tree’s resin, attracts more males and female beetles to the tree in an attempt to overwhelm the tree's defenses. Once a host tree has been infected, the pheromone component changes. This shifts new incoming beetles to other nearby trees to begin a new attack. This behavior produces ‘spots’ where a close group of trees can quickly all become infested and killed.
Management is by suppression through 'cut and leave' or 'cut and remove' techniques. Both infested trees and buffer trees are cut down to prevent the brood from spreading. In the south, infected trees are cut as soon as infections are identified and immediately sent to the local sawmill to be turned into usable building material. This is, unfortunately, not a realistic option for us on Cape Cod, as the infrastructure for a working sawmill is not present (to our knowledge).
When the 2025 late winter thaw comes, it is possible that throughout the summer, we see these beetles begin their destruction of our pitch pines. The first step for us is identification; if we cannot identify the pest, we cannot begin addressing the challenge. A standard defense mechanism for our pine trees when attacked by insects attempting to infest it is to push out sap to fight back against the invaders. Distressed trees attacked by SPB will have a few distinct characteristics. First, you will see many resin spots where the tree is pushing out sap. Unlike their turpentine beetle cousin, who prefers the lower section of trees, these beetles do not discriminate. The sap will run in a long cylinder, or the sap will glob, where insects attempt to infiltrate and overwhelm the tree. The other major sign is that the tree's crown will discolor to a light brown or red from its standard green.