The pine pitch moth, Dioryctria spp., is an interesting critter we have seen a lot of recently. Well, maybe we haven’t seen it, but we have seen plenty of its signs. Unfortunately, it is a booger to control. Zimmerman Pine Moth is the most common species in Kansas.
Signs of the Pine Pitch Moth
The pine pitch moth will cause large masses of pitch on the interior canopy of the trees. The pitch masses occur on the trunk and larger branches or around the junctions. New pitch masses are bright yellow and soft. The old pitch is grayish, looks weathered, and is hard. The adults are rarely ever seen, and it is only the larvae that cause damage to the tree.
Damage
Minor infestations of pine pitch moth may cause insignificant damage, but larger infestations can kill branches and cause trees to become weak. The most severe damage typically occurs on trees that are less than 20 feet tall in urban areas.
Treatments
The easiest (or at least cheapest) way to treat pine pitch moth is to scrape off the pitch masses with a putty knife and remove the larvae. This may not be practical if the masses are very high in the tree or if the tree canopy is very tight are restricts access. Scraping the pitch can also be very time-consuming if the infestations are extensive.
Chemical control is also a viable option in some cases but is not practical for windrows or numerous pines. The pitch protects the larvae from chemical sprays. Adults are not easily controlled because they lay eggs over a long period of time. The most efficient way to protect the trees is by direct trunk injection. That being said, sprays can be effective if you get them in mid-august when the larva is hatching from the eggs or mid-April before the larvae burrow into the tree.
If you have questions or need help getting control of pine pitch moth, contact us. We would be happy to give you options. Or, to learn about other pine problems we face, click here.
