Trusted stewards of Idaho's resources, from main street to mountain top

Insects & Disease

We provide technical assistance and training to private landowners and forest managers, designed to minimize insect and disease risk.

Our focus is on prevention and suppression of damaging insects, diseases, and weeds before and during outbreaks. We promote restoration of tree species most suited to the soils and environment in order to grow long-lived, productive and healthy forests.

Prevention is the best means to protect trees. Treatments focused on prevention result in reduction of tree mortality; thinning dense stands, applying preventative chemical barriers, pruning and favoring existing tree species most resistant to forest pests are good examples. Pest surveys and monitoring can prevent a pest from increasing to damaging levels and reduce tree mortality, when early detection is followed by a rapid response.

The IDL Forest Health staff cooperate with other state and federal agencies to complete several annual pest detection and monitoring surveys.

  • Aerial detection surveys locate, identify, and map insect damage agents and the impacted tree species across most forested lands in Idaho.
  • Monitoring surveys for the native Douglas-fir tussock moth provides predictive data of the next cyclic outbreak and informs management decisions to control the pest.
  • Pheromone trapping surveys for the European and Asian gypsy moths detect incipient populations. Early detection of non-native pests increases the probability that eradication efforts will be effective and prevent widespread, long-term damage and mortality to urban and rural forests.

Idaho Response Plan for Invasive Insect and Disease Tree Pests Click here for PDF document - Idaho Response Plan for Invasive Insect and Disease Tree Pests


  • For questions specific to a location
    10 Supervisory Areas
  • For statewide programmatic questions
    Forest Health Program
    Coeur d'Alene Staff Office
    (208) 769-1525

Landowner Outreach