Cook County, Minn. (06/16/2025)—Cook County is experiencing a multi-year outbreak of spruce budworm, impacting balsam fir and spruce trees throughout the county. Landowners need to consider how to respond to the impacts of budworm feeding on their trees.
University of Minnesota Extension has released a new guide for landowners that outlines spruce budworm ecology, impacts, and management options. This guide is available to view online at z.umn.edu/sprucebudworm, and hard copies are available at the Cook County Extension office in the Cook County Community Center at 317 W 5th St. in Grand Marais.
“Landowners with forested acreages of all sizes are worried about what the spruce budworm outbreak will mean for the future of their woods. This guide provides practical information that landowners can use right away to make decisions about how to respond to the outbreak”, said Sarah Waddle, Cook County UMN Extension Educator. Options for management vary based on the size of your woods and the kinds of trees present.
Landowners can use the guide to get a better understanding of the history of spruce budworm in Minnesota, the current situation, and outlook for the future. “Spruce budworm outbreaks are impacted by a variety of factors”, notes Anna Stockstad, Extension Educator for Forest Ecosystem Health, “This guide gives landowners a clearer understanding of how spruce budworm has interacted with the landscape in the past, and what the current outbreak might mean for the forests of northeast Minnesota into the future.”
Spruce budworm produces one generation of eggs per year that mature from larvae into adult moths. Feeding damage from larvae can be seen on the tips of balsam fir and spruce branches. Landowners considering chemical treatment of yard trees should make a plan to treat their trees during this larval feeding stage. To learn more about the lifecycle of this native insect, and treatment considerations, view the guide at z.umn.edu/sprucebudworm.
