Tussock moth defoliation; note the defoliated young ponderosa pine in the center. Silvies Valley area, Malheur National Forest, Oregon.
More about the defoliation from Mike McWilliams:
"Sometimes [the defoliation] is just in the tops, but more usually whole trees, grand fir and Douglas-fir and crossing over on to ponderosa pine! Messy feeding, more yellow than red. Whole hillsides are defoliated, and the spatial accuracy of the polys seemed good, although we also saw severe defoliation further west that it was mapped (T18S, R31E, sec 30)."
Photo by: Mike McWilliams
Date: August 29, 2018
Credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Blue Mountains Forest Insect and Disease Service Center.
Source: Mike McWilliams collection.
Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection:
www.fs.usda.gov/main/r6/forest-grasslandhealth
