Archives

Common HRD Treatment No Longer Available

Posted on by akabelowsky
A pine stump with a Heterobasidion root disease fruit body with old brown growth in the center and new, bright white growth along the edges.

A Heterobasidion root disease (HRD) fruit body with new white growth observed in the fall. Photo: Wisconsin DNR

The Wisconsin Department of Natural Resources Forest Health Newsletter reports that the fungicide Rotstop® C is no longer available in North America.

Rostop® C is commonly used to protect against Heterobasidion root disease (HRD) during conifer timber harvests. It has been discontinued in the North American market. Cellu-Treat® is now the only registered and available to prevent HRD in Wisconsin. Check out the article from DNR Forest Health for more detail.

As always, remember to report your pesticide use when applying these or any other pesticides on property in the MFL Certified Group. You can use the online reporting form or send the required information to MFLForestCertification@wisconsin.gov.

New Forest Service Publication Translates Research For Landowners

Posted on by akabelowsky
The cover of a USDA Forest Service publication called "Managing Your Woodland: Forestry Research Translated for Landowners"

The cover of a U.S. Forest Service publication called “Managing Your Woodland: Forestry Research Translated for Landowners.” / Graphic Credit: USDA Forest Service

By Wisconsin DNR

Have you ever heard a forester talk about shelterwood or group selection and found yourself wondering what they are talking about?

Or maybe you read those terms in your forest management plan and aren’t entirely clear what they mean? If so, you might want to check out a new publication called Managing Your Woodland:
Forestry Research Translated for Landowners [PDF].

The U.S. Forest Service recently released the publication, which breaks down forest ecology, silviculture and various forest management systems for landowners and other non-forestry experts. Although the publication comes out of the Northeast United States, the tree species, forest types and forest management are not entirely different from the forests and forestry practices in Wisconsin.

Armillaria Root Disease: A Fungal Killer

Posted on by akabelowsky
A photo showing that after bark has been removed from a declining white spruce, the white mycelial mat of Armillaria can be seen under the bark.

Bark has been removed from a declining white spruce to show the white mycelial mat of Armillaria under the bark. / Photo Credit: Linda Williams, Wisconsin DNR

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

Armillaria is a root-rot pathogen that usually lives quietly under the soil. But when trees experience stress, the fungus can attack and colonize the roots of the stressed tree.

Armillaria can infect many different species of trees, and trees of any age or size, but the result for the tree is usually a slow decline and eventual death. Stressors can include drought and flooding, defoliation from insects or diseases or physical damage such as when roots are severed.

Continue reading “Armillaria Root Disease: A Fungal Killer” →

New Forest Health Specialists Take To The Woods

Posted on by akabelowsky

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

It’s time for River Mathieu and Tim Shively to put all their education and research to work.

Mathieu and Shively are the newest additions to the Wisconsin Department of Natural Resources (DNR) Forest Health team. Both started on June 30, filling Forest Health Specialist vacancies.

Continue reading “New Forest Health Specialists Take To The Woods” →

Gall Causes Bull’s-eye Spots On Maple Leaves

Posted on by akabelowsky
A photo showing that maple eyespot galls have created colorful, concentric patterns on red maple leaves.

Maple eyespot galls create colorful, concentric patterns on red maple leaves. / Photo Credit: Linda Williams, Wisconsin DNR

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

Colorful “bull’s-eye” spots on maple leaves are maple eyespot galls, caused by the tiny ocellate gall midge (Acericecis ocellaris).

The adult midge lays eggs on the underside of the leaves. Once the eggs have hatched, the larvae feed on the leaves. That feeding causes the leaf to develop telltale colorful, concentric circles in that area of the leaf.

Continue reading “Gall Causes Bull’s-eye Spots On Maple Leaves” →

Dusky Birch Sawfly Larvae Defoliate Birch Leaves

Posted on by akabelowsky
A closeup photo showing that while feeding on a white birch leaf, dusky birch sawfly larvae raise into an S shape when a potential predator is noticed.

While feeding on a white birch leaf, dusky birch sawfly larvae raise into an S shape when a potential predator is noticed. / Photo Credit: Linda Williams, Wisconsin DNR

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

Dusky birch sawfly (Croesus latitarsus) is a native sawfly that feeds on white birch and occasionally river birch and yellow birch. Larvae feed in a group at the edges of birch leaves and abandon part of the midrib before moving on to another leaf.

Defoliation is typically light, with a few dozen leaves per tree being eaten. This defoliation is only problematic on young seedlings with few leaves. There may be two generations of larvae in a year.

Continue reading “Dusky Birch Sawfly Larvae Defoliate Birch Leaves” →

Veiled Polypore Fungi Growing On Red Pine Bark

Posted on by akabelowsky
Closeup photo of veiled polypore fungi showing as yellow, leathery fruiting bodies on the bark of dead red pine trees.

Veiled polypore fungi show as yellow, leathery fruiting bodies on the bark of dead red pine trees. / Photo Credit: Linda Williams, Wisconsin DNR

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

You may have seen these leathery, yellow fungi growing on recently dead red pine trees and wondered if they were what killed the tree. The short answer: No, they did not kill the tree.

The veiled polypore (Cryptoporus volvatus) is a decay fungus that grows on the bark of red pine in the year after they die. They can be found anywhere on the trunk of the tree.

Continue reading “Veiled Polypore Fungi Growing On Red Pine Bark” →

Heavy Seed Crop And Thin Tops On Maples

Posted on by akabelowsky
A photo of a maple tree branch showing the production of large seed crops, creating off-color leaves that are smaller than normal into early summer.

Maple trees producing large seed crops may have off-color leaves that are smaller than normal into early summer. / Photo Credit: Linda Williams, Wisconsin DNR

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

Scattered maple trees across parts of the Northwoods have produced heavy seed crops this year.

When trees produce so many seeds, it reduces the amount of energy available for producing leaves. As a result, those leaves can appear smaller and off-color into the summer. With fewer leaves produced, these trees will continue to look very thin throughout this year’s growing season.

Continue reading “Heavy Seed Crop And Thin Tops On Maples” →

Non-Native Caterpillars Attacking Non-Native Euonymus

Posted on by akabelowsky
A wide view of a shrub covered by Euonymus caterpillars' web branches as they feed on the leaves of Euonymus species.

Euonymus caterpillars web branches as they feed on the leaves of Euonymus species. / Photo Credit: Wisconsin DNR

By Michael Hillstrom, DNR Forest Health Specialist
Michael.Hillstrom@wisconsin.gov

Euonymus caterpillars (Yponomeuta cagnagella) made a dramatic appearance in June, webbing and defoliating Euonymus shrubs in several counties.

Multiple species of Euonymus may be attacked, including spindle tree, winged (e.g., burning bush), eastern wahoo, winter creeper and others. Winged euonymus is listed as Restricted in Wisconsin’s invasive species rule NR40.

Continue reading “Non-Native Caterpillars Attacking Non-Native Euonymus” →

Tan Tamaracks? It Could Be Larch Casebearer

Posted on by akabelowsky
A photo showing severe defoliation of a tamarack tree by larch casebearer, with most needles mined out by the larvae.

Severe defoliation of a tamarack tree by larch casebearer shows most needles mined out by the larvae. / Photo Credit: Linda Williams, Wisconsin DNR

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

If you’ve noticed tamarack trees with tan or light-brown foliage, you’re probably seeing the work of the larch casebearer.

As foliage began to expand this spring, the caterpillars of this invasive moth became active and began to feed. The tiny caterpillars mine out the needles of tamarack and use them as “cases” to protect themselves, hence their name.

Continue reading “Tan Tamaracks? It Could Be Larch Casebearer” →