Make Your 2023 Spongy Moth Treatment Plans Early

By Bill McNee, DNR Forest Health Specialist, Oshkosh 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”

Harvest Timing Affected By Spongy Moth

By Bill McNee, DNR Forest Health Specialist, Oshkosh or 920-360-0942

Numerous spongy moth egg masses on a bur oak in southern Waukesha County, November 2022.

Numerous spongy moth egg masses on a bur oak in southern Waukesha County, November 2022. Photo: Bill McNee, Wisconsin DNR.

Forest managers planning silvicultural treatments in spongy moth susceptible stands (containing a large proportion of host species including oak, birch, aspen and basswood) are encouraged to annually conduct egg mass surveys in the few years prior to the scheduled treatment to predict if heavy defoliation is likely. The results may indicate that management activities should be altered or delayed until an outbreak has ended. At present, stands that were heavily defoliated in 2022 or are predicted to be heavily defoliated in 2023 are most likely to need a management delay or alteration.

It is recommended that a time interval be left between a stress agent (such as heavy defoliation or significant drought) and stand thinning so that the trees can recover from pre-existing stress before being subjected to additional stress. One growing season is a common interval for healthy stands that are not being subjected to drought or other stresses. A longer interval is suggested if the tree stress has been more severe or if the stand was not healthy and vigorously growing at the time of defoliation. The same interval is probably appropriate regardless of which stress agent is the pre-existing one. A protective aerial spray may prevent tree stress from defoliation but is usually not economically viable due to the high cost of an aerial treatment.

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DATCP: Dead Spotted Lanternflies Detected On Nursery Stock From Out-of-State

On Nov. 3, 2022, the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) received a report of spotted lanternfly from a Walworth County landowner. The observant landowner had found multiple dead and a single dying adult spotted lanternfly on nursery stock purchased from an Illinois nursery. This serves as a reminder to always inspect your stock upon arrival in the nursery trade and prior to planting in your yard.

See the full article in DATCP’s What’s Growing On? November Newsletter.

Learn more about spotted lanternfly on DATCP’s website.

Spotted Lanternfly with wings outspread

Bur Oak Blight Confirmed In Fond du Lac County

By Bill McNee, DNR Forest Health Specialist, Oshkosh,

Recent lab examination has confirmed bur oak blight in Fond du Lac County. The disease affects only bur oaks and is caused by the fungus, Tubakia iowensis.

Map of Wisconsin counties where bur oak blight has been confirmed.

Map of counties where bur oak blight has been confirmed. Map credit: Wisconsin DNR.

Continue reading “Bur Oak Blight Confirmed In Fond du Lac County”

Ambrosia Beetles Attack Sugar Maple Regeneration

By Kyoko Scanlon, DNR Forest Pathologist, Fitchburg,

This summer, the Forest Health Lab received sugar maple seedlings with brownish yellow leaves, which were sent by a Waukesha County landowner who observed many understory sugar maple seedlings and saplings quickly turning brown throughout the summer. This mortality continued until the end of September. The landowner wanted to know why these plants were dead and dying.

Seeding with yellow leaves surrounded by green seedlings.

Affected seedlings exhibit yellow and brown leaves. Photo: Wisconsin DNR

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Don’t Dump Your Garden Waste

By Jaqi Christopher, DNR Forest Invasive Plant Specialist, Rhinelander,

When cleaning up your garden this fall, be sure to dispose of yard waste properly. Not only is dumping on public lands illegal, but it is harmful to the environment.

A large pile of pine needles, leaves and branches dumped along the forest edge.

This garden waste was dumped along an ATV trail in a state forest and can be a pathway for invasive plants and diseases that affect our public lands. Photo: Wisconsin DNR

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Attention Hunters: Help Slow The Spread Of Invasive Species!

By Jaqi Christopher, DNR Forest Invasive Plant Specialist, Rhinelander,

With the dropping temperatures and changing leaves, it’s beginning to feel like fall hunting season.

While you travel across the state to check hunting spots or tend to food plots, look for unwanted hitchhikers on your clothing and equipment. Seeds from invasive plants like garlic mustard, tansy and spotted knapweed can travel far distances in the mud on your vehicle, trailer, ATV, shoes and clothing.

Two women on either side of a mud-covered black truck with gear and a black dog in tow prepare for a day of duck hunting.

Inspecting and cleaning vehicles, equipment, gear and pets before and after recreating can help slow the spread of invasive species. Photo credit: Wisconsin DNR

Continue reading “Attention Hunters: Help Slow The Spread Of Invasive Species!”

Twolined Chestnut Borer Attacks On The Rise

By Paul Cigan, DNR Forest Health Specialist, Hayward, or 715-416-4920

Twolined chestnut borer (TLCB) attacks on oak trees have increased in numerous Wisconsin counties, with decline and associated mortality in the last two growing seasons, most noticeably since August.

Symptoms of infestation by this native beetle are initially seen in mid-July on the outer portions of branches in the upper crown. Leaves begin to fade from green to yellow to red. Within a matter of weeks, they turn brown and remain on the branches for weeks to months. Their foliage may also appear sparse or completely bare (Fig. 1).

Trees with twolined chestnut borer symptoms

Figure 1. Northern red oaks with symptoms of twolined chestnut borer, ranging from crown thinning and leaf chlorosis like the tree on the left (early stage) to dead top branches like the tree on the right (intermediate stage). Photo: Wisconsin DNR

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Moving Firewood Can Spread Invasive Species

An image of an insect walking away from burning firewood in a forest with the caption, “Buy it where you burn it.”

Don’t Move Firewood, The Nature Conservancy

October is Firewood Month! Help prevent the spread of invasive insects and diseases by buying firewood where you burn it.

Firewood Scout can help you find local firewood for sale.

See the DNR website for more information on invasive species and forest health. Continue reading “Moving Firewood Can Spread Invasive Species”

Bernie Williams Retirement

Bernie Williams

Bernie Williams was the Forest Health Team’s worm specialist.

By Becky Gray, DNR Forest Health Team Leader, Fitchburg, or 608-220-3022

While Bernie Williams might yet become a famous artist or comedian, her work with the DNR Forest Health Program was retired on Aug. 29, 2022. Bernie reached minor celebrity status through her presentations on invasive plants and worms across Wisconsin and the country. She was awarded for Outstanding Contribution to Accomplishing the Division of Forestry’s Purpose in 2018 because of her role with the Best Management Practices (BMPs) for Invasive Species, NR40 and her dedication to outreach and education. We are really going to miss Bernie’s humor and crazy stories and wish her all the best as she takes her garden, bees and travels to the next level!

For invasive plant questions, please contact Mary Bartkowiak or Jaqi Christopher. For worm questions, please contact Scott Schumacher.