Urban Forestry News

Eastern Tent Caterpillar Webs Common

Posted on by akabelowsky

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

Photo of web of eastern tent caterpillars.

Eastern tent caterpillars and their webs start out small but grow quickly. Photo: Linda Williams, Wisconsin DNR.

Have you seen trees along roadsides with white webs in them? Eastern tent caterpillars (ETC) are hatching and beginning to feed on host trees, including cherry, apple and crabapple.

Landowners and homeowners may notice the white silken tents forming in branch forks. Although they form unsightly nests, ETC is a native insect, so management is not typically necessary. Even completely defoliated trees will produce new leaves within a few weeks.

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Multiple Oak Defoliators Active Now

Posted on by akabelowsky
Photo of oak leafroller caterpillar on a leaf.

Oak leafroller caterpillars web leaves together as they feed. Photo: Wisconsin DNR.

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

Watch for defoliators in your oak trees this summer. You may have already heard news reports about spongy moth caterpillar populations being high this year, but there are some native caterpillars to watch for this year as well.

In 2022, oak leafroller caterpillars caused significant defoliation to oaks in areas of northeastern and northwestern Wisconsin, as well as in Blue Mound State Park. Many other areas experienced lesser amounts of defoliation from oak leafroller.

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Spongy Moth Forecast Caution Issued

Posted on by akabelowsky

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

Photo of mature spongy moth caterpillar

Mature spongy moth caterpillar on a leaf. Photo: Bill McNee, Wisconsin DNR

Wisconsin Department of Natural Resources Forest Health staff are cautioning Wisconsin residents that the next two months could bring the worst spongy moth outbreak in more than a decade.

The caterpillars of this invasive insect prefer to feed on oak, birch, crabapple, aspen and willow leaves, but will also feed on many other tree and shrub species.

Southern Wisconsin and parts of the north are already in a high-population outbreak that is predicted to continue and spread. Populations have remained high due to a low incidence of caterpillar-killing diseases last summer. In addition, weather conditions in 2023 are favorable for the caterpillars and unfavorable for Entomophaga maimaiga, a fungus that kills spongy moth caterpillars.

Property owners are encouraged to examine their trees and take action.  Specifically:

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Document Trees Planted This Year

Posted on by patricialindquist

Dan Buckler, DNR Urban Forest Assessment Specialist, Milwaukee, daniel.buckler@wisconsin.gov or 608-445-4578

As there is every glorious spring, there has been a flurry of tree planting in Wisconsin. Each little tree, from seed to sapling, is a hope and prayer that we make for the future. But as each reader knows, that future might be many years away.

While you nurture these arboreal miracles, why not take a couple minutes to document the trees in the Wisconsin Tree Planting Map? The map was designed to help track trees planted to advance the state’s pledge to the Trillion Trees Initiative.

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Wisconsin DNR Begins State Nursery Biochar Trial

Posted on by patricialindquist

By Brian Zweifel, DNR Forest Products Specialist, Brian.Zweifel@wisconsin.gov

What is Biochar?

Microscopic structure of biochar. Photo credit: UK Biochar Research Centre

Biochar is basically just charcoal with a special mission, to be used in the soil. The US Biochar Initiative (USBI) defines it as “carbonized biomass obtained from sustainable sources and sequestered in soils to sustainably enhance their agricultural and environmental value under present and future management.” 

Biomass, such as unmerchantable wood waste, is transformed into this carbon-rich material in a low oxygen environment, cooking most non-carbon materials out of it and leaving the material’s basic structure intact. This carbon skeleton is what gives biochar many of its desirable properties. 

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USDA Biological Control Facility Seeks Ash Trees To Battle Emerald Ash Borer

Posted on by patricialindquist

Asks Landowners To Donate Infested Ash Trees

USDA staff cut a ‘bark window’ in green ash to uncover signs of emerald ash borer. Photo credit: USDA

The U.S. Department of Agriculture (USDA) is asking Wisconsin landowners for their help. Emerald ash borer (EAB) is an invasive insect from Asia that was first introduced into the United States in 2002. Since its discovery, EAB has caused the death and decline of tens of millions of ash trees. USDA uses ash trees to combat the pest to help preserve and protect the tree species.

Wisconsin landowners have donated live, infested ash trees to USDA’s EAB biological control program. The wood is used to grow EAB’s natural enemies and release them in Wisconsin and 31 other infested States as well as D.C. where they are attacking and killing EAB. USDA needs more ash trees to continue this work and is hoping more Wisconsin residents will consider donating their ash trees this year.

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Photo Collage Of Arbor Day Celebrations

Posted on by patricialindquist

Scroll down to see how communities around the state celebrated Arbor Day in 2023!

Governor Tony Evers attended the village of Germantown’s Arbor Day celebration on Friday, April 28. Village Park and Recreation staff organized the event with help from Wendland Nursery and the Wisconsin DNR. In addition to village staff and leaders, there were approximately 35 elementary students in attendance, all part of the Kids Club (an after-school program at County Line School). DNR Urban Forestry Coordinator Olivia Witthun spoke with the students and presented the community with their 19th annual Tree City USA award. Olivia was assisted by DNR Forestry staff Mike Warnke and Kim Sebastian. The local nursery provided a planting demonstration and gave each student a plant or vegetable to go home with.

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First Downs For Trees Celebrates 13 Years

Posted on by patricialindquist

On April 20, the First Downs for Trees program celebrated its 13th year by distributing 403 trees to 16 Brown County communities for planting. First Downs for Trees is a cooperative effort between the Wisconsin Department of Natural Resources (DNR), the Green Bay Packers, Wisconsin Public Service (WPS) and corporate sponsors Essity and Green Bay Packaging, Inc.

The program donates trees to participating communities based on the number of first downs in the previous season.

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Prepare — Spongy Moth Caterpillars To Return

Posted on by akabelowsky

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

Spongy moth caterpillars clustered below a sticky barrier.

Spongy moth caterpillars clustered below a sticky barrier. Photo: Mark Guthmiller, Wisconsin DNR

This June and July, spongy moth populations are predicted to reach damaging levels in parts of Wisconsin. Populations began to rise in 2020, and this is likely to be the third year of the pest outbreak in some regions of southern Wisconsin.

At present, damaging populations are expected to be most noticeable in southern counties, counties to the north of the city of Green Bay, and in far northern Wisconsin near Lake Superior. Additional areas are likely to have high populations that are more concentrated in size.

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