Care for your woods

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:

Continue reading “Spongy Moth Forecast Caution Issued” →

Aerial Spraying Coming To Four State Properties

Posted on by akabelowsky

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

Spray aircraft used in spongy moth control

Spray aircraft used in spongy moth control. Photo: Bill McNee, Wisconsin DNR

The Wisconsin Department of Natural Resources (DNR) is taking action in the coming weeks in its battle against spongy moth (formerly known as gypsy moth) caterpillars.

An airplane will spray parts of four DNR properties to reduce the population of the hungry pest.

This year, high numbers of spongy moths threaten to strip trees of their leaves and may even kill high-value trees at these properties.

Continue reading “Aerial Spraying Coming To Four State Properties” →

Emerald Ash Borer Found In Vilas County

Posted on by akabelowsky
Adult emerald ash borer beetle.

Adult emerald ash borer beetle. Photo: Wisconsin DNR.

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

Vilas County has the dubious distinction of becoming the first new Wisconsin county in 2023 to have a discovery of emerald ash borer (EAB).

EAB continues to spread into areas of northern Wisconsin. The first Vilas County detection was in the town of Lincoln. Additional infested trees have since been found in the town of Cloverland and the city of Eagle River. Continue reading “Emerald Ash Borer Found In Vilas County” →

USDA Seeks Donations Of Infested Ash Trees

Posted on by akabelowsky

By Kyle Loughlin, Field Team Lead, USDA-APHIS
kyle.m.loughlin@usda.govor 734-732-0025

A window cut into a tree’s bark shows signs of emerald ash borer infestation.

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

The U.S. Department of Agriculture (USDA) is asking Wisconsin landowners for help in the battle against emerald ash borer (EAB).

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.

The USDA is asking Wisconsin landowners to donate live ash trees infested with EAB to support USDA’s biological control program. The staff will use the wood to rear EAB’s natural enemies, which will then be released in Wisconsin and 31 other EAB-infested states and Washington, D.C.

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Heterobasidion Root Disease Approaches

Posted on by akabelowsky

By Alex Feltmeyer, Forest Health Specialist, Plover, Alexandra.Feltmeyer@wisconsin.gov or 715-340-3810

A Heterobasidian root disease fruiting body at the base of a white pine sapling

A Heterobasidion root disease fruiting body is found at the base of a white pine sapling in the understory. Photo: Wisconsin DNR Forest Health

Heterobasidion Root Disease (formerly annosum root rot or Fomes root rot) is a serious disease of conifers that causes reduced height, shoot and diameter growth along with thin and yellowish/red foliage, ultimately causing mortality.

The disease becomes established in a new stand when spores of the fungus land on freshly cut stumps made by any forest management that creates cut stumps. After the disease becomes established, it spreads underground through root systems into adjacent trees. In this way, we often find pockets or groups of trees in various stages of decline.

Movement through the root systems contributes to significant spread throughout stands of conifers, impacting the regeneration of conifers within these pockets.

Mortality usually starts occurring three to eight years after a thinning operation. During this time, perennial fruiting bodies of the fungus begin to develop around the base of cut stumps or dead trees.

Continue reading “Heterobasidion Root Disease Approaches” →

Hungry Squirrels Find Trees Tasty

Posted on by akabelowsky

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

Maple branches with light colored areas where squirrels removed bark.

Squirrels remove the bark of maples, leaving bright bare spots. Photo: Wisconsin DNR

It’s the time of year when we start to see scattered maple trees stripped of their bark. Squirrels cause this damage — which can be limited to a few small areas the size of a tennis ball or can extend to cover many feet of branches or the main stem.

The squirrels are going after the cambium layer, just under the bark, that tastes slightly sweet from the sap. Smooth bark is easier for squirrels to chew, so young trees or branches with thin bark are likelier to be stripped than those with older, furrowed bark.

At this time of year, the pale wood of the branches that have had the bark stripped off is nearly white; later in the season, this wood will darken or even turn black with sooty mold. This type of feeding can remove enough bark to girdle the branches or the main stem, causing the tree to die from that point to the end of the branch.

Branches that are not completely girdled will continue to grow, and callus tissue will begin to grow over the wounds. If branches are nearly girdled, they may leaf out this spring and then suddenly wilt and die as hot weather hits because the tree can’t deliver enough water to keep those leaves alive. Continue reading “Hungry Squirrels Find Trees Tasty” →

Sign Up For Oak Wilt Vector Emergence Estimate Daily Email Notification

Posted on by patricialindquist

By Kyoko Scanlon, Forest Pathologist, Fitchburg, Kyoko.Scanlon@wisconsin.gov or 608-235-7532

Oak wilt is a serious disease that occurs when insects carrying oak wilt fungal spores land on a healthy oak tree’s fresh wound. To prevent oak wilt infections, it is important to avoid pruning, wounding and harvesting oaks when these insects are abundant, generally from April through July. Predicting exactly when these insects start to emerge in the spring can be difficult as their emergence is highly weather-dependent, and spring weather varies significantly from year to year.

In 2021, the Oak Wilt Vectors Emergence Thermal Model tool, a unique estimation tool, was developed as a collaborative project between the University of Wisconsin-Madison and the Wisconsin DNR to help with these predictions. This online tool offers localized recommendations about the emergence status of the two most important insects that transmit oak wilt in Wisconsin. The interface uses a degree-day model (Jagemann et al., 2018) constructed from insect trapping data and actual weather data, which helps refine the beginning of the periods when you should avoid pruning, wounding or harvesting oaks.

A screen shot of the oak wilt vector emergence homepage where the location and date data is entered to model growing degree days.

UW Extension’s Oak Wilt Vectors Emergence Thermal Model can help predict when oak wilt vectors may be coming. Photo Credit: UW Extension

Continue reading “Sign Up For Oak Wilt Vector Emergence Estimate Daily Email Notification” →

Make Plans To Control Spongy Moth Before The Eggs Hatch

Posted on by patricialindquist

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

Spongy moth (formerly known as gypsy moth) egg masses typically begin to hatch in April as temperatures warm. Each mass that hatches may produce up to 1,000 leaf-eating caterpillars.

Now is a great time to inspect your trees for egg masses and treat or remove any masses within reach. Wisconsin weather has been favorable for this pest over the last three years and populations have grown.

Photo of three spongy moth egg masses on the underside of a pine branch in Walworth County.

Three spongy moth egg masses on the underside of a pine branch in Walworth County. Photo: Bill McNee, Wisconsin DNR.

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Spongy Moth Management Webinar: March 8 at 6 p.m.

Posted on by patricialindquist

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

Spongy moth populations increased dramatically in 2022 and the outbreak is expected to continue in 2023.

Landowners interested in learning more about spongy moth management options are encouraged to attend an upcoming webinar hosted by UW Extension at 6 p.m. on March 8, 2023.

This is a free event, but registration is required. DNR Forest Health Specialist Mike Hillstrom and UW-Madison Insect Diagnostic Lab entomologist PJ Liesch will discuss a variety of effective management tactics for reducing spongy moth damage in varied settings from high value urban trees to forests.

A flyer for an upcoming webinar about spongy moth management that will take place virtually at 6pm on March 8, 2023.

UW Extension’s spongy moth management webinar can help you prepare to care for your land this spring.

Make Your 2023 Spongy Moth Treatment Plans Early

Posted on by brenna.denamur

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

As long as weather conditions are favorable for the spongy moth* (formerly known as gypsy moth) population, the current outbreak is predicted to continue and spread to other parts of Wisconsin in 2023. Property owners are encouraged to examine susceptible host trees (including oak, birch, crabapple, aspen and willow) and plan ahead.

Spongy moth egg masses on a tree next to a penny for size comparison.

Spongy moth egg masses are tan-colored lumps that are larger than a penny, about the size of a nickel or quarter. Photo: Wisconsin DNR

Continue reading “Make Your 2023 Spongy Moth Treatment Plans Early” →