Resistance of Douglas-Fir to Western Spruce Budworm: Results of a Preliminary Progeny Test

摘要

Second- and third-instar larvae of Choristoneura occidentalis placed on 3-month Pseudotsuga menziesii seedlings from seven different stands dispersed over all test seedlings and exhibited a feeding preference. Reduced feeding relative to the test mean was observed on progeny from a stand that has survived a longterm and severe budworm outbreak.