Acres Treated (project completed on July 9, 2001):
Mazama AU: 15,229 ac
8-Mile AU: 800 ac
Wolf Creek AU: 177 ac
Total Treated: 16,206 ac
2001 Project Final
July 2001 (159 pages, 1.9 MB)
Executive Summary (101 KB)
Project Area, Accomplishments, and Maps (App. A) (689KB)
Entomology (136 KB)
Logistics (87 KB)
Air Operations (178 KB)
Finance/Safety/Information/Critique (156 KB)
Appendices B - H (1.1 MB)
Assessment of changes in canopy closure... Kent Woodruff, April 2003 (150 KB)
* These documents are all PDF format. Download a free copy of the latest version of Acrobat Reader.
Starting in the mid- to late 1990s, Douglas-fir tussock moth (DFTM) populations rose for several years east of the Cascades in Oregon and Washington. As described in the Final Environmental Impact Statement, land managers identified specific areas where heavy defoliation by tussock moth would likely cause unacceptable impacts on wildlife, watershed, recreation, and other resources.
Two Records of Decisions were issued: the first Record of Decision (ROD) covered the Colville, Wallowa-Whitman, Ochoco, Malheur, Fremont, and most of the Umatilla National Forests, and the second ROD covered the Wenatchee, Okanogan, Winema, and a township on the Umatilla National Forests. The RODs stated that areas with high tussock moth populations may be treated with either TM-BioControl (a naturally occuring virus that affects only DFTM and two other western tussock moth species) or Bacillus thuringiensis var. kurstaki (a bacteria that is less species specific and can affect more of the moth and butterfly species when eaten). The RODs further stipulated that TM-BioControl would be used first until the supply was depleted.
Fall 2000 surveys indicated potentially high tussock moth populations on ~35,000 acres of Areas of Concern on the Okanogan National Forest. Virus infection levels for egg masses collected in the fall of 2000 averaged about 14%. Three analysis units were identified. Portions of some analysis units were dropped from the proposed treatments after additional sampling in May through July, 2001 indicated non-outbreak levels of tussock moth populations. Treatment began on June 7, 2001, and was completed on July 9th. Post-treatment monitoring of tussock moth population densities and defoliation in 2001 is planned.
In a separate project coordinated through the State of Washington's Department of Natural Resources, approximately 3,000 acres of private lands were treated in early June 2001 with the virus.