Blue stain in ponderosa pine which was not associated with insects. Sisters, Oregon.
Photo by: F.P. Keen and Rumbold
Date: June 1932
Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection.
Source: Bureau of Entomology, Portland Station Collection; La Grande, Oregon.
Image: PS-122
Image provided by USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection:
www.fs.usda.gov/main/r6/forest-grasslandhealth
