Forest Health News

New map illustrates damage from EAB

Forest health staff recently produced a map that highlights a gradient of damage from southeastern to northwestern Wisconsin, which roughly corresponds to the length of time EAB has been present in these parts of the state. Whatever the level of damage, homeowners and landowners should consider treating healthy ash, including trees that have responded well to previous treatments, or removing declining, untreated ash before they become hazardous and even more costly to remove.

County-level map of damage from EAB to ash tree populations in 2019

County-level assessment of damage to ash population by emerald ash borer, 2019.

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Invasive plants, ticks and you

Most people are familiar with the impacts of invasive plants to natural areas, but did you know that invasive plants can be hazardous to human health? Did you also know there is a new app available to learn about tick activity near you and help researchers by recording your own tick encounters?Forested setting with tree in foreground and sign attached to tree that says beware of ticks. Continue reading “Invasive plants, ticks and you”

Leaf beetle spreading in southern Wisconsin

Mike Hillstrom, forest health specialist, Fitchburg, Michael.Hillstrom@wisconsin.gov, 608-513-7690

Viburnum leaf beetle is a relatively new invasive insect from Europe that feeds on the leaves of viburnums and causes mortality after a few years of repeated defoliation. Along with the killing of native viburnum species, which are highly susceptible to the pest, impacts include a higher likelihood of invasive species becoming established following the mortality. Continue reading “Leaf beetle spreading in southern Wisconsin”

Pine wood nematode in Waushara County

By Alex Feltmeyer, forest health specialist, Plover, alexandra.feltmeyer@wisconsin.gov, 715-340-3810

Pine wood nematode (PWN) was recently found to be infecting Scotch pine in Waushara County. Symptoms of pine wood nematode include rapid crown browning (within 3 months) in late summer, rapid drying of wood and presence of blue-stain fungi in the wood.

Row of pine trees with browning needles from pine wood nematode infestation.

Symptomatic trees dying from pine wood nematode. Photo by Alex Feltmeyer. 

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Dead and dying ash are hunting hazard

By Bill McNee, forest health specialist, Bill.McNee@wisconsin.gov, 920-360-0942 and Andrea Diss-Torrance, invasive forest insects program coordinator, Andrea.DissTorrance@wisconsin.gov, 608-264-9247

Hunters should avoid placing tree stands in or near ash trees, especially in the southern half of Wisconsin, the Mississippi River region and in Door County. Many ash trees in these areas are dead or dying from attack by emerald ash borer (EAB), becoming weaker and more likely to break even with little to no added weight. Continue reading “Dead and dying ash are hunting hazard”

Slow the spread by sole and tread – revisited!

By Mary Bartkowiak, invasive plants specialist, Rhinelander, Mary.Bartkowiak@wisconsin.gov, 715-493-0920

There’s so much to enjoy about fall and so many activities to take in before the blanket of snow changes our landscape. Something to keep in mind is that the introduction of invasive plants can play a role in changing the landscape, too.

Slow the spread by sole and tread - logo and image of boots that could carry invasive seed Continue reading “Slow the spread by sole and tread – revisited!”

Look for gypsy moth egg masses

By Bill McNee, DNR forest health specialist, Oshkosh, Bill.McNee@wisconsin.gov, 920-360-0942

Fall is an excellent time to look for and dispose of gypsy moth egg masses that were laid in the summer. Since egg masses usually don’t hatch until April, information gained from fall/winter surveys can be used to avoid gypsy moth damage before the following spring and summer.

Spraying egg masses with oil kills the eggs inside, preventing hundreds of caterpillars from hatching next spring.

Spraying egg masses with oil kills the eggs inside, preventing hundreds of caterpillars from hatching next spring.

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Pesticide applicator training offered in 2020

By Kyoko Scanlon, forest pathologist, Fitchburg, Kyoko.Scanlon@wisconsin.gov, 608-275-3275

The Wisconsin Pesticide Applicator Training (PAT) program with University of Wisconsin Extension is offering a training session for Forestry (Category 2.0) in January 2020. The training is a one-day indoor session to review the materials in the training manual. A certification exam will be administered at the end of the day by Wisconsin Department of Agriculture, Trade and Consumer Protection. 

This training will be held January 24, 2020 in Stevens Point at the Portage County Courthouse Annex Building (1462 Strongs Avenue).

Pre-registration is required and the fee is $30. For more information, visit the PAT website. When you are ready to register, visit the PAT program online ordering page

Fall is a great time to look for HRD

By Mike Hillstrom, forest health specialist, Fitchburg, Michael.Hillstrom@wisconsin.gov, 608-513-7690

Considered one of the most destructive diseases of conifers in the northern hemisphere, HRD is very difficult to eradicate once established. Infestation of a conifer stand may significantly impact stand management, making early detection of the disease extremely important.

new white growth on old HRD conk

HRD fruit body with new white growth on infested stump. Credit: DNR Forest Health.

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Oak health issues in summer 2019

By Mike Hillstrom, forest health specialist, Fitchburg, Michael.Hillstrom@wisconsin.gov, 608-513-7690

The most commonly reported forest health issue in recent weeks has been unhealthy looking oaks. Symptoms ranging from rapid mortality to gradual decline to superficial have been observed on all species of oak this summer.

affected oak tree with dead leaves in lower half of crown

White and bur oaks are being impacted by a variety of health issues in late summer 2019, including fungal leaf infections and bur oak blight. Symptoms are most severe in the lower half of this tree’s canopy. Credit: DNR Forest Health.

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