• Thomson, A.J.
  Pacific Forest Research Centre Canadian Forestry Service Victoria, British Columbia
  
• Alfaro, R.I.
  Pacific Forest Research Centre Canadian Forestry Service Victoria, British Columbia
  
• Van Sickle, G.A.
  Pacific Forest Research Centre Canadian Forestry Service Victoria, British Columbia
  
• Sundaram, A.
  Research Scientist Forest Pest Management Institute Canadian Forestry Service Sault Ste. Marie, Ontario
  
• Wheeler, Ronald E.
  Chevron Chemical Company
  
• Akey, David H.
  USDA Agricultural Research Service
  
• O'Dell, Thomas M.
  USDA Forest Service Forest lnsect and Disease Laboratory
  

Evaluating western spruce budworm impact on trees that are defoliated, but not killed, is complex and must be based on estimates of the reduction in quantity and quality of stem wood that results from budworm feeding. At the Pacific Forest Research Centre, Victoria, British Columbia, we are investigating the reduction in radial growth over the bole of the tree, and the height and volume growth losses in relation to defoliation level.