- Bean, J. L.
- Batzer, H .O.
One of the most important phases of spruce budworm control through cutting practices is the logging of high risk stands in advance of a possible epidemic. Stands with high concentrations of mature and over-mature balsam fir, or those containing a high proportion of poor vigor trees, are more susceptible to budworm injury and are believed less able to recover after several years of heavy defoliation. White spruce is less susceptible to budworm damage than balsam fir, while black spruce ls seldom severely damaged. Now that a spruce budworm epidemic ls threatening the Lake States, a risk-rating is needed to determine which stands are in greatest danger of damage.