Abstract
Percentage parasitism by seven insect parasites of the western spruce budworm, Choristoneura occidentalis Freeman, was not significantly different among crown aspects. Parasitism by two hymenopterous parasites was significantly different among crown levels in either one or both hosts. Other parasites were either insufficiently abundant to provide an adequate test, or percentage parasitism differed insignificantly among crown levels or host types. Because percentage parasitism was not generally different among crown levels, any level could have been sampled.