ACCOUNT OF A RECENT SPRUCE BUDWORM OUTBREAK IN THE LAURENTIDE PARK REGION OF QUEBEC AND MEASURES FOR REDUCING DAMAGE IN FUTURE OUTBREAKS

Pulpwood stands in the Laurentide Park region of Quebec were subjected to defoliation by the spruce budworm between 1946 and 1958. Progress of the outbreak was traced from survey records and from radial growth data from 102 localities. The apparent reasons for the temporary reduction in population level from 1951 to 1953, and for the collapse of the infestation in 1958 are discussed. Estimates based on information provided by the various operators in the area place the total amount of merchantable softwoods destroyed at 5.4 million cords, while calculations based on radial growth studies reveal that approximately 1.8 million cords were lost through reductions in increment. About 1.6 million cords were salvaged before the dead wood was rendered unusable by sapwood rots. Measures that would reduce losses from future outbreaks are proposed and discussed.