Forest Health News

Rotstop® C No Longer Available In North America

Posted on by akabelowsky
Photo of a worker manually applying fungicide, imbued with blue dye, to a freshly cut tree stump to fight the spread of fungal diseases such as Heterobasidion root disease.

A worker manually applies fungicide, imbued with blue dye, to a freshly cut tree stump to fight the spread of fungal diseases such as Heterobasidion root disease. / Photo Credit: Wisconsin DNR

By Kyoko Scanlon, DNR Forest Pathologist, Fitchburg
Kyoko.Scanlon@wisconsin.gov

The manufacturer, Lallemand Plant Care, recently decided to remove Rotstop® C fungicide from the North American market.

As a result, the product is no longer available for purchase in North America. If you already have the product and have stored it in an appropriate space, you may still use it as a preventative treatment for Heterobasidion root disease (HRD) as long as the expiration date has not arrived.

Continue reading “Rotstop® C No Longer Available In North America” →

Web-Spinning Caterpillars Not Spongy Moth

Posted on by akabelowsky

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov,  920-360-0665

You may already be seeing the web nests created by eastern tent caterpillars, which hatch early in the spring and start feeding on emerging leaves as the weather warms up.

Eastern tent caterpillars can sometimes be mistaken for forest tent caterpillars or spongy moths. Check out the DNR’s comparison fact sheet, which includes pictures for identification and control options. Continue reading “Web-Spinning Caterpillars Not Spongy Moth” →

Ice Storm Damage Found In Northeastern Forests

Posted on by akabelowsky
Photo of young red pine trees bent over and flattened by the weight of ice and snow. after an ice storm.

Young red pine trees bent over and flattened by the weight of ice and snow. They will not recover. / Photo Credit: Levi Koski

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov, 920-360-0665
and Sam Blake, DNR Forester, Crandon
Samuel.Blake@wisconsin.gov, 715-216-6396

On Saturday, March 29, and continuing throughout the day on Sunday, March 30, northeastern Wisconsin experienced freezing rain, causing ice accumulations of one-quarter to one-half inch.

The freezing rain weighed down branches of trees. Then, to add to the weight of the ice on the trees, the freezing rain changed to wet, heavy snow with accumulations of up to 7 inches. The combination of ice and wet, heavy snow caused branches to break. In some cases, entire trees broke off.

Pine plantations seemed to be hardest hit, with the tops of some trees becoming so weighed down that trees leaned over and stems snapped. Continue reading “Ice Storm Damage Found In Northeastern Forests” →

Campers Reminded: Don’t Move Firewood

Posted on by akabelowsky
A stock photo of a family roasting marshmallows over a campfire.

Going camping? It’s important to remember not to move firewood. Instead, buy it within 10 miles of where you will use it. This will help to prevent the spread of invasive pests. / Photo Credit: Istockphoto.com

By Wisconsin DNR

Camping season is about to enter full swing, and campfires are a Wisconsin summer staple.

That makes this a good time for the Wisconsin Department of Natural Resources (DNR) to remind the public of the importance of protecting Wisconsin’s forests and trees by not transporting firewood long distances.

Even after a tree has died, firewood can carry pests or diseases — on its surface or inside the log —  which can attack or infect other trees. To help prevent the spread of invasive insects and diseases, always get your firewood near where you will use it.

Continue reading “Campers Reminded: Don’t Move Firewood” →

DNR Offers Two Knotweed Fact Sheets

Posted on by akabelowsky
A roadside photo showing how quickly species in the knotweed complex can grow and create large infestations.

Species in the knotweed complex grow very quickly, causing large infestations on roadsides like this one. / Photo Credit: Randy Westbrooks, Invasive Plant Control, Inc., Bugwood.org

By Wisconsin DNR

With the scourge of knotweed about to gear up for another growing season, the Wisconsin Department of Natural Resources (DNR) is offering information.

The DNR has created two fact sheets to instruct general and urban landowners on the best control methods for the fast-growing invasive plant.

Continue reading “DNR Offers Two Knotweed Fact Sheets” →

Columbian Timber Beetle Fact Sheet Debuts

Posted on by akabelowsky
Photo showing staining, in the shape of a many-pointed star, evident in the cut ends of silver maple logs.

Staining, in the shape of a many-pointed star, is evident in the cut ends of silver maple logs. / Photo Credit: Chris Firgens, Oconto County Forest

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665

Columbian timber beetle (Corthylus columbianus) is an ambrosia beetle native to the eastern United States.

In Wisconsin, we have had reports of Columbian Timber Beetle (CTB) attacking silver maple in the northeastern and lakeshore areas of the state, dating back to the early 1990s. The insects have caused significant staining from repeated attacks. In southern Wisconsin, CTB can attack oaks to a lesser degree, including bur, northern red and white oak.

Continue reading “Columbian Timber Beetle Fact Sheet Debuts” →

Japanese Stilt Grass History StoryMap Debuts

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The main page of the Wisconsin Department of Natural Resources' new StoryMap on Japanese Stilt Grass on the Coulee Experimental State Forest.

The main page of the Wisconsin Department of Natural Resources’ new StoryMap on Japanese Stilt Grass on the Coulee Experimental State Forest. / Graphic Credit: Carter Hellenbrand, Wisconsin DNR

Carter Hellenbrand, DNR Invasive Plant Field Specialist, Fitchburg
Carter.Hellenbrand@wisconsin.gov

The Wisconsin Department of Natural Resources (DNR) Forest Health program has created a new StoryMap documenting the history of Japanese stilt grass on the Coulee Experimental State Forest in La Crosse County.

Users will be able to see an overview of Japanese stilt grass, how to identify it and what control efforts have been implemented since this plant was discovered in 2020.

Continue reading “Japanese Stilt Grass History StoryMap Debuts” →

UW-Madison’s Raffa Talks Trees’ Natural Defenses

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Photo of Ken Raffa, professor emeritus with the University of Wisconsin-Madison Department of Entomology.

Ken Raffa, professor emeritus with the University of Wisconsin-Madison Department of Entomology. / Photo Credit: University of Wisconsin-Madison

By Art Kabelowsky, DNR Outreach and Communications, Fitchburg
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

Do you pity the poor tree, forced to stand defenseless against the ravages of insect pests, fungi and disease?

Then, you have not listened to Dr. Ken Raffa discuss the impressive natural defenses trees have developed.

Raffa, a professor emeritus with the University of Wisconsin-Madison’s Entomology Department, recently appeared on Proforest Podforest podcast to discuss the topic “Inside the Tree’s Natural Defense.”

Continue reading “UW-Madison’s Raffa Talks Trees’ Natural Defenses” →

Forest Health Staffers Plan Public Appearances

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By Art Kabelowsky, DNR Outreach and Communications, Fitchburg
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

Forest Health specialists with the Wisconsin Department of Natural Resources are booked to give public presentations during May.

The list of events that are open to the public: Continue reading “Forest Health Staffers Plan Public Appearances” →

2025 DNR Spongy Moth Spray Plans Announced

Posted on by akabelowsky
Photo showing an airplane spraying pesticide over trees at Devils Lake State Park in Sauk County to help in the control of spongy moth caterpillars.

An airplane sprays pesticide over trees at Devils Lake State Park in Sauk County to help in the control of spongy moth caterpillars. / Photo Credit: Sue Johansen, Wisconsin DNR

By Art Kabelowsky, DNR Outreach and Communications
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

The Wisconsin Department of Natural Resources (DNR) has finalized aerial spraying plans for its 2025 Spongy Moth Suppression Program, with maps for the five selected treatment areas available online.

The treatment sites are at three state parks in Juneau, Marinette and Sauk counties that are highly valued for their recreational use. A total of 544 acres of trees will be treated with an aerial spray of “Foray” bacterial insecticide containing Bacillus thuringiensis var. kurstaki.

Continue reading “2025 DNR Spongy Moth Spray Plans Announced” →