Research entomologist Torolf Torgersen checking Douglas-fir tussock moth larvae. Mobile lab. La Grande, Oregon. OR/WA/ID Douglas-fir tussock moth control project.
Photo by: Unknown Date: 1974
Credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection. Source: Division of Timber Management, Insect and Disease Control print collection; Regional Office, Portland, Oregon.