Zimmerman Moth

Zimmerman Pine Moth

Pines have been popular landscape choices for their hardiness and year round aesthetic appeal. Recently, many of these species have fallen prey to the destructive Zimmerman moth, Dioryctria zimmermani.How can I tell if my pine tree is affected? In early summer, sawdust present on lateral branches may indicate a problem. Symptoms will appear the worst in late summer when larvae are the most active. The presence of a creamy white pitch mixed with frass on large branches or main trunk may indicate pest activity.

Larvae from the Zimmerman moth burrow into the trunk and branch bases of pine trees, which weakens limbs and makes them very susceptible to wind or storm damage. Eventually the trunk may break and the entire tree may die.

What can I do to prevent the spread of Zimmerman moths? Proper sanitation is the most effective cultural control of Zimmerman moth larvae. This pest is known to re-infest the same trees year after year; removal of these “brood trees” can help effectively control moth populations. Trees weakened or otherwise damaged are highly attractive to moth larvae; treating or removing these trees will give healthy potential hosts a better chance at survival.

Diseased Pine Needles Spruce rust and needlecast are diseases caused by various fungi. Although rarely fatal, they make trees unattractive, ineffective for screening and more susceptible to other stresses.

How can I tell if my spruce trees are affected? In the case of spruce rust, symptoms become visible in midsummer, when pale yellow bands can be seen on the current year’s growth. The previous year’s needles, if infected, will brown and fall. The following spring, telia (fungal fruiting bodies) will appear.

The needlecast fungi also form microscopic black fruiting bodies in which thousands of spores form on the infected needle.

What can I do to prevent the spread of these diseases? If detected early, infected branches can be pruned to slow or potentially stop the spread of the disease. Reducing moisture around plants by spacing trees widely and maintaining good weed control to allow for drying and good air circulation are recommended. Contact your arborist if you suspect the presence of spruce rust or needlecast in order to develop a management plan suited for your landscape.


Find out, and learn how you can protect your ash trees. Ask your arborist or visit the Emerald Ash Borer page on www.savatree.com for details.

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