Spruce budworm

In Region 1, it appears that while we are finding more and more defoliated stands each year, the amount of defoliation in individual stands has leveled off or decreased over the past two years. Defoliation on white spruce appears somewhat less than in 1996 with most plot sites having fewer or similar egg mass counts compared to 1996. However, one spruce plantation in Section 21, T145N-R31W on federal land experienced about 60% top-kill and 10% tree mortality. This stand has had defoliation for six or more years but was never identified until the 1996 aerial surveys found it. It was discovered this year during the routine ground checking of the aerial survey polygons.

In Region 2, the acreage of spruce budworm defoliation decreased, especially in the Superior National Forest. High populations continued in northeast Itasca, southeast Koochiching and northwest St. Louis Counties. Populations are expected to stay at high levels in these locations and increase in northwest St. Louis Co.

In Region 3, defoliation of white spruce is up slightly compared to last year and the egg mass counts are very slightly down.