This insect pest attacks all
pines but is generally more serious on Scotch and Austrian
pines. It rarely infests spruce or Douglas-fir.
The larvae of the pine moth bore into the main trunk and large
branches of pines. Occasionally, the terminal leader of the tree will be
The most common symptom is the appearance of heavy pitch or sap flow
along the main trunk or large branches. This flow often originates from
the area around branch whorls or on shoots near the terminal leader.
The tops of trees may break off and patches of dead foliage where branches
die in the canopy will become apparent. Large, globular pitch masses often
mixed with reddish frass may also be present on the main stem or on large
During the first two weeks of April, apply
an insecticide labeled for Zimmerman pine moth onto the main
trunk and larger branches of the tree. Early application and good coverage
of stems and branches with the spray are essential for effective control.