MCH (Methyl Cyclo-Hexanol) Douglas-Fir Beetle Protection

These are. PDF files and take several seconds to load 

Douglas Fir Beetles – What Trees Are At Risk

Douglas Fir Trees (Rocky Mountain Douglas-fir Pseudotsuga menzeisii var.glauca) is the most common conifer tree species found in the forests of Montana and Idaho. This tree displays an ability to grow across a wide variety of environments. It spreads easily due to its relatively light seed that can catch wind currents and disperse up to 2 miles. Douglas-fir is a hearty and resilient tree that is moderately fire resistant, has the ability to withstand snow, wind, drought, and mild insect infestation. Despite being a highly sustainable tree, Douglas Fir Trees are susceptible to an array of insects and pests. The most well know enemy of Douglas-Fir Trees is Douglas-Fir Beetles. 

Douglas-fir Beetles (Dendroctonus pseudotsugae) prefer to first bore into host Douglas-fir trees that are large, old, and already otherwise stressed. The stress can be from other pests such as defoliating Tussock Moths, or Western Spruce Budworms. Trees also may be experiencing stress from other environmental factors such as fire, drought, or disease. While Douglas-fir Beetles outbreaks tend to start in large, old, and stressed trees, beetles are opportunistic and during outbreaks will also attack healthy trees within a stand after stressed trees have reached carrying capacity.

How Pine Beetles Damage Trees

Adult Douglas-fir Beetles (Dendroctonus pseudotsugae) bore through the bark of Douglas-fir trees into the cambium, then lay eggs. When the eggs hatch the larvae continue to spread though-out the cambium damaging tree tissue that is vital to the survival of the tree. While alone Douglas-fir Beetle is unable to kill a host tree on its own, once a beetle has infected a tree other beetles will quickly follow.

How Douglas Fir Beetles Spread

Many Douglas-fir Beetles simultaneously attacking a tree can quickly overwhelm a Douglas-fir Tree’s natural defenses and kill it. Douglas-fir Beetles coordinate attacks on trees by following chemical signals called pheromones. The pheromone signals can be submitted from the host tree or by beetles that have found a susceptible host tree. Other Douglas-fir Beetles follow the aggregation pheromones (vacancy signal) or an anti-aggregation pheromone (NO vacancy signal) and soon the host tree is overwhelmed and an outbreak has begun within a stand of trees. Peak flights for Douglas-fir Beetles generally is April-May dependent upon weather conditions.

How to Protect Trees from Douglas Fir Beetles

Management of Douglas-Fir Beetles can take many forms within an Integrated Pest Management (IPM Plan) Plan. Sometimes the best option might be tree removal and thinning, spraying, or preventative synthetic semiochemical pheromone patches that are attached to trees. Preventative pheromone patches called Methyl Cyclo-Hexanol (MCH) is the synthetic version of the Douglas-fir beetles natural anti-aggregation pheromone. This pheromone essentially sends out a “NO VACANCY” signal which tells beetles this tree cannot support additional beetles, effectively stopping an infestation and outbreak before it can begin. Preventative application measures must be taken prior to flight, and is most effective when applied in March.

MCH Bubble Packs: Safeguarding Pine Trees from Beetle Trouble

What Are MCH Bubble Packs?

MCH Bubble Packs are like tiny bodyguards for pine trees. They help protect these valuable trees from pesky beetles that can cause damage.
Imagine these packs as magical shields that keep the beetles away!

How Do They Work?

Timing and Placement: To make sure these bubble packs work effectively, we need to use them at the right time and put them in the right places.
Think of it like planting seeds in your garden. You want to plant them when it’s the best season, right? Same idea here!

When to Use MCH Bubble Packs:

Spring Beetle Season: When spring arrives, so do the beetles. We want to use the bubble packs before the beetle party starts.
In places like the Pacific Northwest and the northern Rocky Mountains, this happens around late April or early May.

It’s like putting on sunscreen before going out in the sun – prevention is key!

How Many Bubble Packs?

The number of bubble packs depends on how big the area is that we want to protect.
For areas bigger than half an acre (that’s like half a football field), we use 30 bubble packs per acre. Imagine each bubble pack as a little soldier guarding the trees!

Where to Put Them?

Strategic Locations: We attach these bubble packs to trees, snags (which are dead trees), shrubs, or even fence posts.
The best height for them is between 6 and 8 feet above the ground.
It’s like hanging birdhouses – we want them at just the right height!

Spacing Matters:

Even Distribution: If the area is smaller than 2 acres, we spread out the bubble packs evenly around the edges.
Imagine drawing dots around the edge of a circle – that’s how we place them.
For larger areas, a combined approach is recommended:

Around the Perimeter: Place bubble packs around the edges.
Parallel Lines: Distribute them in parallel lines across the whole treatment zone.

Maintain a spacing of approximately 15 to 20 feet between each bubble pack. Alternatively, you can create a grid pattern with a spacing of 38 feet between bubble packs.

It’s like making a grid on a piece of paper!

Extra Protection:
To be extra safe, we extend the bubble packs 30 feet beyond the area we’re treating.

It’s like having a safety buffer around your favorite game – just in case!


These bubble packs are like secret weapons for our pine trees. They stay active all season long! If there’s a beetle invasion (kind of like a bug party), we might need to use them again next year.