Damage by Zeiraphera diniana (Lepidoptera: Tortricidae) to lodgepole pine ( Pinus contorta) of various provenances

Abstract

Foliar damage by the budmoth, Zeiraphera diniana (Guenée), radial increment of trees and needle lengths were recorded for lodgepole pine, Pinus contorta (Douglas), in Scotland grown from seed of various North American origins. The least susceptible to budmoth damage in the form of defoliation were pines originating from North Coastal (Alaska and British Columbia) localities. In increasing order of susceptibility were pines from South Coastal (Washington and Oregon), Skeena River (British Columbia), Central Interior (British Columbia), Southern Interior (British Columbia) and Washington Cascades (Washington) localities. Indices of foliar damage (assessments of the intensity of defoliation on new shoots in the whole crown, and the frequency of trees with dead leading shoots within a provenance) were related to patterns of monoterpenes in shoot cortical oleoresin, to needle length and to the elevation of lodgepole pine provenance localities. Highest damage levels were sustained by trees belonging to a provenance in which the trees had also gained the most radial increment. However, those trees most damaged by the moth had increments 25% less than for undamaged trees. Longer-term studies are required to evaluate possible delays in recovery from defoliation.