The balsam woolly aphid problem in Oregon and Washington
By: by Norman E. Johnson and Kenneth H. Wright.
Contributors: Wright, Kenneth H.; Pacific Northwest Forest and Range Experiment Station (Portland, Or.)
Series: Research paper -- no. 18.; Research paper (Pacific Northwest Forest and Range Experiment Station (Portland, Or.)) -- no. 18.
Publisher: U.S. Dept. of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station
Published: 1957
Place of publication: [Portland, Or
Language: eng
Number of pages: 34
Subjects: Balsam woolly adelgid -- Oregon.; Balsam woolly adelgid -- Washington (State); Fir -- Diseases and pests -- Oregon.; Fir -- Diseases and pests -- Washington (State)
Notes: "April 1957."

Also issued online.