The spruce budworm, Choristoneura fumiferana (Clem. ) , a native insect of the spruce-fir forest ecosystem, is the most widespread, persistent, and destructive defoliator of coniferous forests in eastern North America (1, 16, 21). Found as far west as the MacKenzie River Valley and throughout the eastern range of its primary hosts balsam fir (Abies balsamea (L.) (MilI.), white spruce (Picea glauca (Moench.) voss.), red spruce (Picea rubens Sarg.), and black spruce (Picea mariana (MilI.) B.S.P.) the spruce budworm is capable of having  significant socio-economic impact in those regions which rely on spruce-fir forests as a primary resource (21).