MN DNR reports extensive spruce budworm infestation
Damage covers over 380,000 acres
MADISON, Wis. – The Minnesota Department of Natural Resources pointed out an extensive infestation of spruce budworms in its 2021 Forest Health Annual Report issued this month. It said the spruce budworm was affecting over 380,000 acres across the state, the most extensive damage in 26 years.
Spruce budworms typically feed on balsam fir and white spruce, according to the report, but can also move on to other species. Infestations normally last 6 to 8 years, but the Arrowhead region of Minnesota has been experiencing one for far longer — dating back to 1954.
The report is based on an aerial survey of 15 million acres of forests in the state conducted in conjunction with the U.S. Forest Service. The surveyed area includes most of Northern and Northeastern Minnesota as well as six counties in the far Southeastern part of the state.
A very dry spring and summer (April to September) impacted forests and may have been a factor In some forest health issues. The survey noted some expansion of oak wilt and emerald ash borer impacts beyond previously known areas.
The full report is available here:
https://files.dnr.state.mn.us/assistance/backyard/treecare/forest_health/annualreports/2021-annual-report.pdf