- Kemp, William P.
Environmental Associates, Inc.
A study was established to evaluate spruce budworm population and defoliation levels on host species in red spruce-balsam fir, white spruce-balsam fir, and red spruce-balsam fir-hemlock forest types in Maine. Population and defoliation sampling as well as laboratory oviposition tests were conducted from June of 1979 through August of 1980. Oviposition tests conducted with laboratory reared spruce budworm moths showed a distinct preference for white spruce foliage when compared to balsam fir, red spruce, and hemlock. Field collected population data indicated forest effects on budworm densities on several host species. Egg to instar-IV budworm survival was highest in the forest type which was a mixture of white spruce and balsam fir. Survival was lowest in the study area where there was a mixture of red spruce, balsam fir, and hemlock. Regression analyses developed to predict budworm densities indicated differing budworm/forest relationships between forest types and within types but between host species. Independent variables used in the regressions were stand parameters and budworm densities. Implications of these results with regard to implementation and recommendations for future work are contained herein.