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Maple Petiole Borer Causes Leaves To Drop

Posted on by akabelowsky

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

Photo of maple leaf found on the ground with broken petiole (leafstalk).

A green maple leaf found on the ground with a broken petiole (leafstalk) due to damage by the maple petiole borer. / Photo Credit: Wisconsin DNR.

Some sugar maple trees in the northern half of Wisconsin experienced leaves dropping to the ground this spring.

These leaves were green and had no apparent areas of damage, but they covered the ground under some trees. A closer look showed these leaves had short petioles (leafstalks) that had been broken off when they fell, which indicates a tiny sawfly larva called maple petiole borer was to blame.

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Acorn Pip Galls, Woolly Catkin Galls All The Same

Posted on by akabelowsky

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

Photo of acorns showing small pip galls.

Pip galls are small, tongue-like protrusions emerging from under the caps of acorns. / Photo Credit: Linda Williams, Wisconsin DNR.

Gall wasp life cycles can be complex. Did you know that acorn pip galls, which I’ve written about several times, have another part of their life cycle that is entirely different? This stage is called the woolly catkin gall.

Both woolly catkin galls and acorn pip galls are caused by Callirhytis quercusoperator, a species of cynipid gall wasp. This gall wasp takes two years to complete development by going through the two parts of its life cycle. Both parts of the life cycle are completed on northern red oak in our area.

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Invasive Plant Control Database

Posted on by patricialindquist

Photo credit: Joseph O’Brien, USDA Forest Service, bugwood.org

Are you looking for information on how to control buckthorn, honeysuckle or garlic mustard? The Invasive Plant Control Database from the Midwest Invasive Plant Network is a terrific resource for learning about the most effective chemical and non-chemical control methods for dozens of invasive plants in the Midwest.

Information was collected from both scientific literature and expert opinions and summarized by the Midwest Invasive Plant Network in partnership with the Mark Renz Lab at the University of Wisconsin-Madison. For each species, information was reviewed by four individuals, including two who identified as experts on control of that species.

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Are Native Trees The Right Fit For Our Downtowns?

Posted on by patricialindquist

By Kim Ballard, Project Canopy, kim.ballard@maine.gov

Photo credit: David Lee, bugwood.org

This article was first published on the website of the Maine Department of Agriculture, Conservation & Forestry. Reprinted with permission.

As urban foresters, we are often asked, “Why do you recommend planting a non-native tree in front of my house/on my sidewalk/in that parking lot?” The question is complex and has as many answers as there are environments in Maine. But it all boils down to “right tree, right place.”

Maine is the most forested state in the nation. Along with our beloved state tree, the eastern white pine, our forests are full of sugar maple, red oak, white birch and eastern hemlock. If you get a chance to wander through these native woods, you’ll notice that the shady air is cooler, moister and perhaps not as breezy as the air around your neighborhood sidewalks. Trees planted in our downtowns face a whole host of conditions – solar reflection, drought, soil compaction, road salt, tunneling winds that forest trees rarely encounter. Can you imagine a majestic white pine on Congress Street in Portland? Even if it could survive, it certainly wouldn’t be very happy. Our downtowns are NOT native spaces, and they cannot support our native species appropriately.

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Don’t Dump Your Garden Waste

Posted on by brenna.denamur

By Jaqi Christopher, DNR Forest Invasive Plant Specialist, Rhinelander, Jacquelyn.christopher@wisconsin.gov

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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Moving Firewood Can Spread Invasive Species

Posted on by brenna.denamur
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” →

New DNR Publication: Results of the 2020 Diverse Urban Species Survey

Posted on by kirsten.biefeld

The Wisconsin Department of Natural Resources (DNR) just released a new publication: Results of the 2020 Diverse Urban Species Survey.

You may have participated in this survey led by DNR Urban Forestry Coordinator Don Kissinger in 2020 (if so, thank you!) Wisconsin municipalities with more than 2,500 residents were asked a series of questions about the types of trees they prefer to plant (such as root stock type and caliper size), which lesser-used species they had successfully planted, which species they cannot find but would like to plant, and whether they use a gravel bed. Continue reading “New DNR Publication: Results of the 2020 Diverse Urban Species Survey” →

DNR Leads Milwaukee Heat Mapping Project

Posted on by kirsten.biefeld

Mitchell Park Domes. Credit: WDNR

Wisconsin DNR urban forest assessment specialist Dan Buckler had been monitoring weather forecasts for a month, waiting for just the right blisteringly hot day to launch a much-anticipated Milwaukee heat island mapping project. He’d been laser-focused on getting the one-day blitz in the books, and July 21 turned out to be go time.

The urban heat island effect explains the phenomenon that densely developed urban spaces are warmer than outlying places due to man-made surfaces (such as asphalt) absorbing and reradiating heat through the day and night. Trees are one method of reducing urban temperatures by providing shade and by putting more water vapor into the air via evapotranspiration.

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Eyes On Beech Leaf Disease

Posted on by brenna.denamur

By Ethan Wachendorf, Forest Health Lab Technician, Fitchburg, ethan.wachendorf@wisconsin.gov or 608-273-6276

Forest owners and land managers should be on the lookout for beech leaf disease (BLD), a destructive disease of beech trees. The disease is primarily found on American beech (Fagus grandifolia) but can also be found on ornamental species like European, Oriental and Chinese beech (F. sylvatica, F. orientalis and F. engleriana).

Multiple symptomatic beech leaves showing dark striping between lateral veins on the underside of the canopy.

Symptomatic striping seen from under the canopy. This photo was taken in Ohio. Photo: Wisconsin DNR

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