Abstract
In 1956, the spruce budworm infestation which had been in progress in the Lower St. Lawrence and Gaspe Peninsula for about eight years, covered the whole territory from the Rimouski River to the eastern tip of the Peninsula (Fig. 1). In many localities throughout the region repeated defoliation had been severe enough to cause some trees to die (3) . Had it not been for the extensive aerial spraying operations practised in this region since 1954, tree mortality would undoubtedly have been even more widespread.