Tin collar used on medicated fire-killed Douglas-fir. Tree medication studies. Photo by: J.A. Beal Date: February 15, 1934 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Bureau of Entomology Collection; La Grande, Oregon. Image: BUR-8847 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest insect investigations on the Pacific Slope,...
Topics: divisionofforestinsectinvestigations, 1934, foresthealthprotection, usda, stateandprivateforestry,...