Forest Health Information

Emerald Ash Borer (EAB)


EAB is a destructive insect pest of ash trees. Important changes to the regulation of Emerald Ash Borer in the state of Wisconsin have recently taken place. As of March 30, 2018 Wisconsin will be under a statewide quarantine for EAB. For more information about this recent development, visit the WI DNR's EAB website.

Oak Wilt

Oak wilt was discovered in Bayfield County in 2018.  This is a devastating fungal disease that kills trees in the red oak group (red, black, and northern pin oaks) and also harms trees in the white oak group (white, bur, and swamp white oaks). 

Below are two documents regarding oak wilt specifically in Bayfield County.

Bayfield County Oak Wilt Flyer

Bayfield County Oak Wilt Information

For state-specific information on oak wilt visit WI DNR's website: search for keyword "oak wilt" or view the WI DNR Oak Wilt Handout (PDF).

spongy MOTH

A significant outbreak of Spongy moth (formerly known as Gypsy moth) is currently underway in the northern half of Bayfield County, primarily north of Highway 2.  For detailed information on Spongy moth, including potential options for control, please visit the Wisconsin DNR website at:

View a summary document (PDF) of Spongy moth quarantine regulations for Wisconsin.

For more detailed Spongy moth information, visit Wisconsin's Department of Agriculture, Trade and Consumer Protection (DATCP) website.


Information about diseases, invasive insects, and invasive plants that threaten the health of the forest ecosystem are available at the Wisconsin DNR's Forest Health website.


The Northwoods Cooperative Weed Management Area (NCWMA) is a collective group of state and federal agencies, municipalities, tribes, nonprofits, community organizations, and individuals who have come together to combat invasive species in Douglas, Bayfield, Ashland, and Iron counties in northern Wisconsin.

See what tools are available to you in the NCWMA toolshed, work on plant identification, and learn about what is happening on a local level to combat the spread of terrestrial and aquatic invasive species on the NCWMA website.


- Plant Disease Diagnostic Clinic at UW Madison/UW Extension

- Diagnose plant, tree, weed, or insect problems at University of Minnesota Extension

- Tree identification at WI DNR

- WI DNR Firewood Rules