Mountain Pine Beetle - Down. But Not Out.

Don’t stop fighting this pest late in the game… it could mean disaster for your trees.

I am often asked by clients, “What do you do during the winter?” It’s a common question and they’re often surprised to learn how we fill our time with educational opportunities instead of hibernation. For a moment, landscape pests are held at bay by the cooler temperatures and we have time to hone our skills. The pest management industry is always evolving in response to new chemical technology, new tools, and improved strategies to make our applications more effective and safer for the environment. We also attend a variety of conferences providing us with additional, timely data on the migration trends of certain pests. Pests such as the Mountain Pine Beetle (MPB) migrate in response to environmental pressures. The insect is transported by wind thereby allowing it to quickly infest new areas to support reproductive efforts for the following season.

Central Colorado has been hit particularly hard by the Mountain Pine Beetle infestation and battle-weary property owners are eager to see the plague dissipate. Millions of dollars have been spent over recent years in the desperate attempt to save as many of our pine trees as possible. Thankfully, recent data suggests the gradual movement of the pine beetle out of the Colorado High Country has already begun. The news is not so positive, however, for our neighbors along the Front Range where the insect has a new batch of trees squarely in the crosshairs. While it would appear the time for healing in Central Colorado’s forest is upon us this is actually a time of great peril. Knowledge of an outward migration trend of the Mountain Pine Beetle has left some with a false sense of security. At the same time, financial instability and a sluggish economy has made it increasingly difficult to spend money on continued, preventative spraying treatments. Doctors routinely advise patients to continue taking a medication to its completion even if they’re feeling better. The same holds true for landscape pest control. Property owners have spent an impressive amount of money in recent years to prevent the loss of their valuable trees to this insect pest. Remember that it doesn’t take many successful Mountain Pine Beetle “hits” to bring about certain doom for the tree. Yes, we are seeing the proverbial “light at the end of the tunnel” but don’t let your guard down now before the battle has truly subsided. One mistake now, not continuing with preventative treatments, could spell disaster and render efforts over previous years worthless.

What are my options for preventative control against the Mountain Pine Beetle?

• Trunk Sprays

o Should be performed by a professional arborist. Cannot be applied by a property owner with a common, pump-up weed sprayer.

• Pheromone packs (Beetle Blocks™)

o Safer than trunk sprays and can be installed by the property owner.

o Ideally should be used in combination with trunk sprays for added protection.

• Trunk injections, sound repellency, ODC™

o These are newer technologies still in their testing stage. They do show good potential, and we continue to monitor their progress.

Can a tree be treated once the Mountain Pine Beetle has attacked a tree?

• Unfortunately, no. Current chemical technology only supports prevention, not treatment in response to a successful attack by the insect.

Conclusion:

Only work with a reputable arborist who is experienced and licensed in landscape pest control operations. Specific laws exist for the protection of the public and environment with regards to the release of pesticides. Simply being licensed as an “arborist” does not grant permission to a contractor to legally apply pesticides. The business must be licensed by the state department of agriculture – having shown competency in the use of pesticides. If you’re going to court it’s best to hire an experienced lawyer to help you. Similarly, if you’re considering the use of pesticides on your property seek the guidance of an experienced arborist. He or she brings years of knowledge about the chemical and the equipment necessary to perform the project safely. Always ask to view credentials.

Scale Strikes Vail

While not as well known as the mountain pine beetle, scale insects have been infecting trees at a greater rate in recent years and silently killing trees without much notice. The mountain pine beetle infestation results in the death of the tree the following year, while scale insects starve the plant they feed on over the course of several years leading to its slow “decline”.

A property owner’s first awareness of the problem (and one that results in the most phone calls to our office) is the observation that their tree appears “unhealthy and thin”. Entire branches have died-back and the tree is dropping an unusual amount of needles or leaves. A more thorough investigation exposes small, white specks against the green foliage.These are the sucking insects known as pine needle scale. There are several hundred species of scale active in the United States. In our region of Colorado most of our service calls are in response to pine needle scale, which attacks most evergreens but is typically found on spruce varieties. There is also a scale insect active in our area that is found living camouflaged on the trunks of aspen trees: aspen scale.

Its coloration, similar to that of the aspen trunk, makes it difficult to identify but its damage is similar to that of pine needle scale: a slow decline with no apparent reason. Other components of a landscape—shrubs and flowers, and even houseplants are prone to scale infestations. The result is always the same as the plant eventually succumbs to starvation and slowly fades away.

There are a variety of treatment options available ranging from pesticide sprays, soil injections, trunk sprays, and even direct trunk injections. There are synthetic pesticides, organic pesticides, and even some bionatural control options. All treatments have one thing in common: the scale insect must be treated in the proper stage of its life to result in effective control. This stage is known as the “crawler” stage and occurs right after hatching from their overwintering eggs. The “crawlers” briefly leave the protective, waxy, scale covering and are quite vulnerable to control efforts. They seek out a location on the previous year’s growth to inject their sucking mouthparts and ingest juices. They will remain there for the rest of their lives. Once the insect begins covering itself with the white, waxy, scale covering, however, they are protected against all but systemic pesticides.

What if you suspect scale insects are active in your landscape?
Call a professional. They have the knowledge and experience to offer environmentally sound control options.

Where have scale insects been seen locally?
Pine needle scale is approaching epidemic levels in the Town of Vail. There is an endless supply of spruce trees s in Vail, which assist the scale’s ability to proliferate. Spruces are being skeletonized by the insect and many property owners don’t realize there’s a problem until it’s too late.

Aspen scale has been seen in the Town of Vail and moving westwards towards Gypsum. With its natural grey coloring property owners have no reason to suspect an insect infestation.

Should I be concerned about scale?
Yes. Left untreated it doesn’t go away on its own and its activity always ends poorly for the tree.