Tunnock, Scott, R. Ladd Livingston, Wayne E Bousfield, and United States. Forest Service. Northern Region. State & Private Forestry. 1974. Impact of Egg Viability, Egg Parasitism, and Virus On 1974 Douglas-Fir Tussock Moth Defoliation Potential In Northern Idaho. : Missoula, MT : USDA Forest Service, Northern Region, Division of State & Private Forestry.