Insecticide for bark beetles more harmful than helpful

*Published in the Denver Post newspaper April 1, 2012

Beetle kill is real. My fear of losing  majestic pine trees around our neighborhood and in our yard is palpable. Witnessing the loss of seven big trees on a tiny lot upon which our mountain cabin stood in Idyllwild, California, in 2004, left me with something akin to post trauma stress. Watching tree removal workers, who happened to be prisoners trained and supervised by the California state prison system,  scale, section and drop to the ground seventy-five-year-old trees surrounding our cabin remains etched in my memory as a nightmare does.

Following too many years of drought, California’s forests were decimated by bark beetles beginning around 2000, including the San Jacinto Forest where the tiny hamlet of Idyllwild lays. Because the devastation was widespread, talk of bark beetles infiltrated daily conversations among virtually all residents of Southern California for years.

In 2005, we relocated to Douglas County, Colorado. News of  beetles sucking the lifeblood of millions of acres of pine forests vampire-fashion was soon on the lips of everyone we met. In flashback style, I began to envision the home we had just purchased in Castle Pines Village being stripped of its giant trees, some 150 years old by estimates of local arborists, the way our little cabin in the San Jacinto Forest had been.  This worry keeps me awake nights.

Beyond hand-wringing, what can we do to save our trees? The short answer:  Not much.

The ravaging of our forests from coast to coast by beetles is a natural event. Extended drought leaves pine trees in distress and vulnerable to beetle occupation. Also, man has contributed to an overpopulation of pine trees standing much too close together, an overcrowding that offers up easy smorgasbord for insects. Widespread prevention of natural forest burning has contributed to this bug epidemic, as well. One thing I now know.  Nature is going to thin the forests, one way or another.

While still residing in SoCal, the hot topic was often spraying insecticide on the trees, which was commonly discounted by experts and laypeople.  The reasoning was that insecticides would have to saturate every surface inch of a vulnerable tree, and remain in place after even the heaviest of rains, to keep hungry beetles out. Certainly, once beetles were under the bark, no amount of surface spraying would make one whit of difference to the fate of the tree. Environmentalist warned of ground water contamination and death to beneficial insects, primarily bees, due to the spraying of the poisons.

This week we received in the mail a news bulletin from the Castle Pines Homes Association concerning the protection of our trees from beetles. While most of the bulletin echoes others I have read from California to Colorado, one notable exception is that our homeowners’ association firmly recommends spraying.

I decided to research further since my knowledge concerning bark beetles comes from another forest and another time. Perhaps experts have new recommendations. In my search for unbiased, independent opinion regarding using insecticides on trees for the purpose of  prevention of beetle attack, I came upon several sources. 

Thousands of news stories can be accessed regarding beetle kill, which has swept the nation the past decade.  Countless websites of government entities from municipal to federal levels offer up information. The two best sources I located relevant to our local interests are the City of Cheyenne, Wyoming, and our own Colorado State University Cooperative Extension Offices. These sources explain matters best, have nothing to sell consumers, and offer up simple preventative tips to help ensure healthy forests, such as keeping trees watered during dry spells, voluntarily thinning your pine tree population, prompt removal of trees known to be infested, and keeping close watch for signs a tree is in distress.

I believe the fate of my own trees and the trees across our state is in the hands of Mother Nature at this point, and always. Though doing something often feels better than doing nothing, in the case of war with pine beetles, I believe spraying pine trees with insecticides causes more harm than benefit.  After weighing the facts,  I won’t be spraying insecticide on my pine trees.