Pest

Protect your trees from disease by pruning when they have no leaves

By Paul Cigan, forest health specialist, Hayward, paul.cigan@wisconsin.gov, 715-416-4920

With the new year upon us, healthy lifestyle habits are sure to be on many people’s minds as they plan for changes in diet and exercise. The new year is also the perfect opportunity to make healthier choices for trees! Winter is the ideal time for tree pruning while avoiding harmful, disease-carrying pests such as the tiny beetles that carry oak wilt from one tree wound to another.

Woman pruning a tree with no leaves on it.

Pruning during winter is less likely to invite unwanted, disease-carrying pests like the beetles that carry oak wilt from one tree to another. Credit: sasapanchenko.

Continue reading “Protect your trees from disease by pruning when they have no leaves”

2019 Forest Health Annual Report now available

Forest health annual report now available for 2019.

The Forest Health Annual Report summarizes notable impacts for that year of pests, diseases and weather on the health of Wisconsin’s forests. The report is a collaborative product created by DNR forest health specialists from around the state. It outlines the damage and spread of both native and invasive pests and diseases during that year and puts these into context of observations from previous years. Management programs and their results are also described. Highlights from the 2019 annual report include:

  • Dramatically increased decline and mortality from emerald ash borer in southern WI
  • New county and township detections of oak wilt
  • Precipitation record and major storm damage
  • Summary of state nursery studies on Diplodia sapinea, galls on jack pine seedlings, and testing new fumigants to replace methyl bromide

This year’s annual report is available on the DNR forest health homepage. Previous annual reports, including historical reports dating back to 1951, are archived and available upon request. Contact your local forest health specialist if you’d like digital copies of any archived annual reports.

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.

Continue reading “New map illustrates damage from EAB”

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”

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. 

Continue reading “Pine wood nematode in Waushara County”

Are you planning to treat your ash trees? If not, stay safe and save money by removing them ASAP!

The emerald ash borer (EAB) will kill nearly all of Wisconsin’s ash trees that are not protected by insecticides. If you have healthy ash trees in your yard, you have an important decision to make: protect your trees with insecticides or have them removed. Either way, time is of the essence. If you delay in treating your ash trees, the treatment may be less effective. And if you wait to remove them, removal costs will be greater and safety hazards will only get worse.

Credit: Joseph O’Brien, USDA Forest Service, Bugwood.org

What makes infested trees so dangerous?

The structural integrity, or strength, of ash branches and tree trunks begins to decline as soon as the tree becomes infested and the wood begins to dry. Lower moisture content increases the risk of branch and trunk breakage, and the timing of breakage is usually unpredictable. Infested trees may also have total trunk failure soon after death, further increasing the chance of dangerous impacts to people and property.

Continue reading “Are you planning to treat your ash trees? If not, stay safe and save money by removing them ASAP!”

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”

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.

Continue reading “Look for gypsy moth egg masses”

Grants: urban wildlife damage abatement/control

Urban Wildlife Damage Abatement and Control (UWDAC) grants help urban areas develop wildlife plans, implement specific damage abatement and/or control measures for white-tailed deer and/or Canada geese.Images of deer and geese - two wildlife species that cause damage in urban environments

UWDAC grants are available to any town, city, village, county or tribal government located within an urban area. Applications must be received on or before December 1 and awards are announced in January of the grant year. For more information please visit, https://dnr.wi.gov/aid/uwdac.html

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.

Continue reading “Oak health issues in summer 2019”