Insects & Diseases

Native forest insects and diseases are important components of forest ecosystems in Oregon and Washington.  By affecting the growth and mortality of individual trees, they influence the species composition, stand structure, and ecological succession of forest stands.  They also have many other important ecological roles, such as recycling nutrients, pollinating plants, and providing food for wildlife.  Healthy forest ecosystems in the Pacific Northwest include thousands of species of forest insects and pathogens.


Aerial Detection Survey

Every year since 1947, aerial surveys have recorded the insects and diseases affecting forests in Oregon and Washington. These annual surveys are cooperative efforts by the Forest Health staffs of the Washington Department of Natural Resources, Oregon Department of Forestry, and the USFS Pacific Northwest Region.

Digital data (GIS shapefiles) and maps from annual aerial surveys are available from 1947 through the present year and maps are available from 2003 through the present year.  More information about aerial detection surveys can be found  here.  


Western Forest Insects & Diseases

View a catalog of online publications and links about western forest insects and diseases.

Currently featuredDouglas-fir Tussock Moth, a native defoliator


Publications and Reports

Annual   Forest Health Highlights reports are available for Oregon and Washington from 1998 to the present as well as  Forest Insect and Disease Conditions reports that date back to 1933.  View 1-page Forest Disease Management Notes for 50+ forest tree diseases and many other publications and reports about western forest insects and diseases.


Field Guides and General Websites