The potential damage of the Saratoga spittlebug to red pine can be predicted by comparing the percentage of ground occupied by sweet-fern with the percentage of ground cover occupied by other nymphal host plants. A risk-rating graph is used to estimate potential damage.
Wilson, Louis F. 1971. Risk-rating Saratoga Spittlebug Damage by Abundance of Alternate-host Plants. Research Note NC-110. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station