• Campbell, Robert W.
  United States Department of Agriculture, Forest Service, Pacific Northwest Research Station
  

Data from six western States provided 1,251 life tables representing western spruce budworm, Choristoneura occidentalis 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 bud- worms (western and eastern spruce budworms, and the jack pine budworm). Several modifications are suggested ¡n current methods for managing budworm-susceptible forests, and suggestions are provided for further studies on the budworm life systems.