How to stop tree-eating beetles the cures & the cautions
The West's largest-ever bark beetle outbreak was decades in the making and resulted from various actions or inactions including fire suppression, climate change, hands-off forestry and logging patterns that left vast ranges of single-age trees of one species or another. Potential solutions are just as varied.
How it helps • Chemicals slow beetles when applied to individual trees. One is a liquid repellent, another a synthetic anti-aggregation pheromone.
Why it's problematic • Logistical nightmare. Hand application to individual trees is required, meaning it's only feasible for select locations.
How it helps • Logging removes food for beetles and salvages commercial value. When conducted rapidly before the next summer it ousts beetles that would fly to the next trees.
Why it's problematic • Stripping the land has consequences for wildlife and water. Massive outbreaks move faster than timber crews, and damaged logs won't work for lumber after a couple of years. In the U.S., permitting timber sales can take years if there are even mills to buy the logs.
Remedy: Slash & burn
How it helps • Caught early in an infestation, beetles can be slowed by pinpoint removal. Aerial surveys with follow-up cutting and winter burning eliminate pest trees.
Why it's problematic • Expensive and weather-dependent. This stalling tactic requires help from eventual winter cold snaps to end an outbreak.
How it helps • Trees fight beetles with a toxic sap, but only do it well with adequate resources. Eliminating competition gives healthy trees maximum sun and water.
Why it's problematic • Too much of the West needs some type of treatment. Costs for that would run into the billions, so thinning happens only at select sites.
How it helps • Beetles following climate change into new turf may find "naive" trees with poor defenses. Some scientists are looking for genetic markers of well-adapted trees that could be seed sources.
Why it's problematic • Not much money has been available because some threatened trees, like whitebark pine, have little commercial value.
Remedy: Shift seeds
How it helps • Trees produce seeds adapted to their local environment, and that environment is changing. Moving seeds from their parents either uphill or to the north could put them more into their comfort zones as climate changes during their lifetimes.
Why it's problematic • Some scientists fear meddling would only impede whatever adaptations natural forests may achieve.