Spring forestry tidbits from DNRC

Being an owner of forested property can bring many upkeep duties. Thinning, burning, road work and monitoring for health can keep a property owner pretty busy. Windstorms this winter have damaged many trees and can make a mess. Unfortunately, these trees become a "buffet" for beetle activity and the insects can spread to healthy trees if not dealt with in a timely fashion. Most forest insects occur naturally throughout Montana, but with some careful planning and cleanup, you can prevent the spread of beetles into your forest.

Douglas-fir beetle typically infests damaged, sickly or recently damaged Douglas-fir trees. We're still seeing an uptick on beetle activity around the area from wildfire and late winter blowdown events. Keep an eye out for fading tops and red boring dust accumulating at the base of the tree to indicate an active attack. Once a tree is infested, it is usually dead in several months even though it may still have green foliage and there is no way to halt the attack. Cutting and removing infested trees from the area within a year (before the next spring) can prevent future infestations and possible death in the adjacent trees.

Landowners wanting to safeguard individual trees or an entire stand can opt to apply anti-aggregation pheromone packets called MCH (methyl-cyclohexanone) prior to April 15. Applications only last for the summer and are specific to Douglas-fir beetle only. Beetles typically emerge from infested trees and seek out new trees to infest between April and May.

Locally residents can purchase these packets from Swan Valley Connections before March 22 by calling 406-754-3137. They are also available at several locations in Missoula.

Broken pine trees can also attract another type of beetle called Pine Engraver (also known as Ips). The beetles act in the same fashion as the Douglas-fir beetle and you can prevent attacks by disposing of the pine tree before the following spring.

Keep an eye out for the colorful and fuzzy Douglas-fir Tussock moth caterpillar as well. It behaves similarly to the spruce budworm. It eats Douglas-fir and other tree needles, and is starting to make an appearance in the valley. Do not touch the Tussock moth caterpillar it as it may cause an irritable skin rash called Tussockosis.

Overstocked forests increase stress on trees because of limited resources and can be a vector for insects or disease to make an impact on tree health. Promoting tree health, proper tree spacing and a variety species/sizes is the best tool for preventing any type of insect outbreak.

Insects, disease and wildfire do not stop spreading at property lines. I encourage you to develop good connections with your neighbors to clean up heavy fuel concentrations on both sides of the property, especially near homes. The Montana Department of Natural Resources and Conservation can conduct a free home fire risk assessment to give you an idea of what you can do to limit your home's fire risk potential. Call DNRC Fire Prevention at 406-244-2392 to schedule an appointment.

One last note: Don't move firewood out of the region! Moving firewood can spread unwanted forest insects into healthy areas. Consider buying locally if you are camping outside the area. If you do move wood, make sure you burn it all and do not leave any behind at your site.

There are a lot of factors that play into an individual tree's health. Sometimes insect activity is a part of a larger forest issue. Please feel free to contact DNRC Clearwater Unit Service Forester Brad French at 406-244-2382 with any forestry questions or for a free forest consultation.