What is a pine borer beetle?

Pine borers are beetles whose larvae tunnel beneath the bark of conifers, causing damage. The most aggressive species belong to the genus Dendroctonus, and they are serious pests to forestry.

Pine borers cause direct damage to trees by interfering with sap flow and destroying cambium. The adults of some species feed on needles and twigs. One species, the pine sawyer beetle, also carries the pine wood nematode from tree to tree. These nematodes can cause rapid wilting and death of the host tree. Pine borers most commonly attack trees that are already dead, dying or weakened and thus help renew forests by removing older trees, but some species do attack healthy trees and have killed millions of acres of trees since 2005.