- Campbell, Robert W.
Research Entomologist, Pacific Northwest Research Station
Data from six western states provided 1251 life tables representing spruce budworm, Choristoneura occidengtalis Freeman. These data provided projection capabilities for defoliation and successive budworm densities, as well as a basis for comparing survival rates among the three principal North American needle eating budworms (western and eastern spruce budworms, and the jack pine budworm). Several modifications are suggested in current methods for managing budworm susceptible forests, and suggestions are provided for further studies on the budworm life systems.