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 and maps from these annual surveys are available for 1980 through the present; survey data from earlier years are currently being digitized.   


Western Forest Insects & Diseases

drawing of an adult male Douglas-fir tussock mothView a catalog of online publications and links about western forest insects and diseases.


Currently featured: Douglas-fir tussock moth


Publications and Reports

Annual reports on Forest Insect and Disease Conditions for Oregon and Washington are available, as are Forest Health Highlights for these states.  View 1-page Forest Disease Management Notes for 50+ forest tree diseases, or many other publications and reports about western forest insects and diseases.

New!    Thirty Years of Root Disease and Bark Beetle Caused Mortality in a Mixed Conifer Forest along the Chiwawa River in Central Washington (2014) by Greg Filip, Angel L.Saaverdra, Sylvia R. Mori and Amy Ramsey-Kroll (2 MB pdf)

Status of Sugar and Western White Pines on Federal Forest Lands in Southwest Oregon: Inventory Query and Natural Stand Survey Results, by Ellen Michaels Goheen and Donald J. Goheen (January 2014; 8 MB pdf).


Field Guides and General Websites