Zimmerman Pine Moth

Zimmerman pine moth is a common trunk borer in Scotch, Austrian, Eastern White, and Red pines. Although it is difficult to control once inside the tree, its life cycle makes it relatively easy to control while on the outside of the tree. Trunk damage appears as white, crusted areas of pitch an inch or two wide at branch whorls. Sometimes this also appears as whitish cones of pitch about one inch in length along with oozing pitch at the branch whorl. The caterpillars are located in the trunk underneath this pitch. They tunnel under the bark as well as deeper into the trunk and base of branches. Commonly, associated branches will die. Tunneling into the trunk for several years weakens the trunk to where it snaps off at that location, causing the loss of the upper part of the tree. The tree survives this loss as lateral buds will break and produce new trunks. However, without pruning, the tree usually becomes multi-trunked from that point upward. This changes the overall appearance of the tree from that of a tall, telephone pole shape into a squatty candelabra shape.