Care for your woods

New Invasive Pest Discovered In Wisconsin

Posted on by akabelowsky

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

A closeup of an elm zigzag sawfly caterpillar consuming a leaf. The invasive insect, new to Wisconsin, was found on an elm tree near the Wisconsin Department of Natural Resources office in Oshkosh on July 16, 2024.

A closeup of an elm zigzag sawfly caterpillar consuming a leaf. The invasive insect, new to Wisconsin, was found on an elm tree near the Wisconsin Department of Natural Resources office in Oshkosh on July 16, 2024. / Photo Credit: Bill McNee, Wisconsin DNR

The invasive insect elm zigzag sawfly (Aproceros leucopada) has been detected in Wisconsin for the first time.

Following the initial Wisconsin discovery in Portage County on July 4. Through Aug. 12, the pest has since been detected in 17 Wisconsin counties. Continue reading “New Invasive Pest Discovered In Wisconsin” →

Spruce Budworm Defoliation Continues

Posted on by akabelowsky

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

Closeup photo showing that webbing created by the spruce budworm caterpillar holds needles and frass and protects the caterpillar. A pupa hangs from the branch.

Webbing created by the spruce budworm caterpillar holds needles and frass and protects the caterpillar. A pupa hangs from the branch. / Photo Credit: Linda Williams, Wisconsin DNR

Although symptoms weren’t as prevalent as in 2023, this year marked yet another year of defoliation from spruce budworm.

Another severe year of defoliation causes additional stress on the trees. Even though there has been a lot of rainfall this spring, it’s still stressful for the trees to face repeated years of defoliation by spruce budworm before they begin to decline and die.

Continue reading “Spruce Budworm Defoliation Continues” →

Dropping Leaves May Indicate Oak Wilt

Posted on by akabelowsky

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

Photo showing that oak leaves that drop from a tree infected with oak wilt may be all brown or all green, or often they will have green near the base of the leaf and the outer portions will be brown or watersoaked green.

Oak leaves that drop from a tree infected with oak wilt may be all brown or all green, or often they will have green near the base of the leaf and the outer portions will be brown or watersoaked green. / Photo Credit: Linda Williams, Wisconsin DNR.

The middle of summer is the time to start watching oak trees for symptoms of oak wilt. Although symptoms show up suddenly and leaves drop quickly, symptoms can emerge anytime between now and when leaves turn color in the fall.

Trees that were wounded in the spring and became infected with the fungus that causes oak wilt will usually die that same year. In established oak wilt pockets, the fungus moves underground through grafted root systems and trees will wilt as the fungus moves into the tree.

Continue reading “Dropping Leaves May Indicate Oak Wilt” →

Upcoming Invasive Plant Management Workshops

Posted on by janness

Southeastern Wisconsin Invasive Species Consortium is teaming up again with Johnson’s Nursery, Inc.TM to offer Invasive Plant Management Workshops in 2024. Take this class to ensure that you are using the most appropriate, efficient, up-to-date and least environmentally damaging methods in those efforts. Continue reading “Upcoming Invasive Plant Management Workshops” →

Invasives And Imposters: Native Look-Alikes To Know

Posted on by akabelowsky

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh;
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Native plants benefit Wisconsin wildlife, pollinators and ecosystems. However, many resemble harmful invasive species, making identifying problem plants in the woods challenging.

It is important to learn a few key characteristics to unmask the imposters and correctly identify the invasive plants. With a little study and practice, you can quickly differentiate between these perplexing pairs.

Continue reading “Invasives And Imposters: Native Look-Alikes To Know” →

Oak Moth Outbreaks May Have Peaked In North

Posted on by akabelowsky

By Paul Cigan, DNR Forest Health Specialist, Hayward;
Paul.Cigan@wisconsin.gov or 715-416-4920

Wide-angle photo showing many oaks across northern Wisconsin with partially defoliated, thin, and yellow-tinted crowns caused by defoliation from the oak leafroller and oak leaftier.

Many oaks across northern Wisconsin displayed partially defoliated, thin, and yellow-tinted crowns caused by defoliation from the oak leafroller and oak leaftier. / Photo Credit: Paul Cigan, Wisconsin DNR

A three-year-long outbreak of oak leafroller moth and oak leaftier moth—two native, early-season oak defoliators—continued this spring in northern Wisconsin, leaving behind tens of thousands of acres of oak-dominated forest with scattered, widespread defoliation.

Partially defoliated, thin and yellow-tinted crowns were visible across portions of Barron, Rusk, Sawyer and Washburn counties, as well as areas in Florence, Forest, northern Marinette and Vilas counties.

Continue reading “Oak Moth Outbreaks May Have Peaked In North” →

Spongy Moth Status Update

Posted on by akabelowsky

By Bill McNee, DNR Forest Health Specialist, Oshkosh;
Bill.McNee@wisconsin.gov or 920-360-0942

A photo showing several trees with spongy moth defoliation in Marinette County in mid-June 2024.

Spongy moth defoliation in Marinette County in mid-June 2024. / Photo Credit: Darrek Sams, Wisconsin DNR

As of early July, we have seen a mix of live and dead caterpillars and tree defoliation that is typical of a late-stage spongy moth outbreak. Reports of defoliation have been received as far north as Florence County.

Recent aerial surveys in southern Wisconsin spotted defoliation in the same general areas as in 2023, but the defoliation has generally been less intense this year. Information for northern Wisconsin has yet to be made available. Refoliating oaks, growing a second set of pale-looking leaves, were seen in Walworth County in early July.

Continue reading “Spongy Moth Status Update” →

Pruning Can Control White Pine Blister Rust

Posted on by akabelowsky

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

Eastern white pines (Pinus strobus) can be beautiful trees in urban and forested areas (they can tower above the rest of the forest’s trees), but they can also attract a deadly disease.

White pine blister rust (Cronartium ribicola), also known as WPBR, is a fungus that can attack branches and the main stem of white pine, causing cankers that continue to grow each year and creating dead spots that can girdle branches or the main stem. Damage from a girdling canker may take years to become severe enough to cause tree decline and mortality. That means you may be able to help your trees and prevent mortality.

Continue reading “Pruning Can Control White Pine Blister Rust” →

Best Disposal Methods For Garlic Mustard

Posted on by akabelowsky

By Erika Segerson-Mueller, DNR Invasive Plant Program Specialist, Oshkosh Service Center
Erika.SegersonMueller@wisconsin.gov or 715-492-0391

Summer can be prime time for invasive plant control, with garlic mustard pulls and many other plant- or location-specific events taking place to confront invasive plants head-on.

Wanting to do your best to help, you might pull garlic mustard along your local hiking trail. But what should you do after you pull it?

Read on for invasive plant disposal tips to ensure you don’t inadvertently do more harm than good with your control efforts.

Continue reading “Best Disposal Methods For Garlic Mustard” →

Invasives Get The Spotlight On Madison TV

Posted on by akabelowsky

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

The fight against invasive plant species in Wisconsin’s forests, woods and natural areas got a big boost over the airwaves in June.

WISC-TV (Channel 3 in Madison) produced a news feature on invasives that included an interview and tour with Wisconsin Department of Natural Resources (DNR) invasive plant specialist and Natural Heritage Conservation representative Mackenzie Manicki.

Continue reading “Invasives Get The Spotlight On Madison TV” →