Abstract
Abstract Reductions in ring width of Douglas-fir, Pseudotsuga menziesii [Mirb.] Franco, trees defoliated for 1 year by the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), are reported. Trees were treated with a nuclear polyhedrosis virus, but the resultant epizootic which killed larvae and reduced defoliation took several weeks to develop and trees sustained varying degrees of damage. No negative effects of defoliation were noted in the year when feeding took place; on the contrary, a growth stimulation occurred. Defoliation levels above 50% resulted in growth reduction for 2 years following defoliation relative to nondefoliated trees. The implications of these growth changes for cost/benefit analysis of control options are discussed. For. Sci. 37(3):959-964.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
