Guidelines: Logging to Control Insects

Logging to Control Insects: The Science and Myths Behind Managing Forest Insect “Pests”

By Scott Hoffman Black

This 88-page report demonstrates that industrial logging is not the solution to combating outbreaks of bark beetles or defoliators, such as tussock moth or spruce budworm. This includes a review of relevant studies on the importance of insects to forest function and the effectiveness of methods used to control forest “pest” insects, and a compilation of summaries of over 150 scientific papers and Forest Service documents.


Key findings in the report include:

  • Native forest pests have been part of our forests for millennia and function as nutrient recyclers; agents of disturbance; members of food chains; and regulators of productivity, diversity, and density.
  • Fire suppression and logging have led to simplified forests that may increase the risk of insect outbreaks.
  • Forests with diverse tree species and age classes are less likely to develop large insect outbreaks.
  • There is no evidence that logging can control bark beetles or forest defoliators once an outbreak has started.
  • Although thinning has been touted as a long-term solution to controlling bark beetles, the evidence is mixed as to its effectiveness.

Former US Forest Service Chief Mike Dombeck gives report his “highest recommendation” and calls it “the most useful publication on the topic of forests and forest pests that I have seen.”

To download a PDF, click here.