Pest

Grant Funds Available For Community EAB Management

By: Abigail Krause, DNR Urban Forestry Coordinator

As more detections of emerald ash borer (EAB) are confirmed in Wisconsin’s northern counties, many communities are just starting to address the management consequences that others having been dealing with for more than a decade. Members of the communities in which you live and work may vaguely know of you as “that one person that knows things about trees.” As such you may get asked: are there any cost-share funds or programs out there to help communities deal with EAB?

The answer is yes! Urban Forestry’s grants can be utilized for EAB related projects. Extra great news: urban forestry regular and startup grants are accepting applications until Monday, Oct. 3.

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Look For Spongy Moth Egg Masses – Larger Outbreak Possible in 2023

By: Bill McNee, DNR Forest Health Specialist, Oshkosh

bill.mcnee@wisconsin.gov or 920-360-0942

Three tan-colored spongy moth egg masses on a single tree branch in Walworth County.

Three spongy moth egg masses on a branch in Walworth County. Photo Credit: Bill McNee, Wisconsin DNR

Now that spongy moth egg laying is complete for 2022, it’s a good time to look for and dispose of egg masses produced by adult moths over the past two months.

Spongy moth egg masses are tan-colored lumps about the size of a nickel or quarter, and are found on trees, buildings and other outdoor objects. They may also be found in protected places such as firewood piles and birdhouses. Newly produced egg masses will feel firm and appear darker in color than older egg masses, which appear faded, feel spongy and do not contain viable eggs. The current-year egg masses will not hatch until next spring.

In 2022, Wisconsin’s spongy moth population grew for a third consecutive summer due to favorable weather conditions and limited caterpillar mortality from diseases. The outbreak was most dramatic in opposite ends of the state. In southern and southeast Wisconsin, several thousand oak-dominated acres were heavily defoliated and very large numbers of property owner reports were received by DNR staff. In Bayfield County, about 80,000 acres of rural defoliation was reported from aspen-dominated forests. Smaller patches of defoliation were also reported from several other counties. Continue reading “Look For Spongy Moth Egg Masses – Larger Outbreak Possible in 2023”

Aspen Leaf Diseases Responsible For Thin Crowns

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

Northeastern Wisconsin saw thin and defoliated aspen trees in early summer this year due to a few diseases. A sample from Marinette County turned up Alternaria leaf and stem blight, Venturia leaf and shoot blight and Phyllosticta leaf spot. Venturia was also noted in central Wisconsin, causing shoot blight, which kills the terminal leaders (growth buds) of young aspen.

Aspen trees with leaves damaged by leaf disease..

Aspen crowns were thin due to multiple leaf diseases. Photo: Wisconsin DNR

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Pine Sawyer Beetle: A Noteworthy Native

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

This time of year, you may see black beetles with long antennae flying around, especially in areas with pine trees. These slow, ungainly flyers are a native longhorn species called white-spotted sawyer beetle, also known as pine sawyer.

Pine sawyers are black beetles with long antennae.

Pine sawyer adult male. Photo: Wisconsin DNR

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Hungry, Hungry Japanese Beetles

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

Japanese beetles (Popillia japonica) are an invasive insect that feed on many plant species. They skeletonize leaves, which means that they eat the material between the veins and often leave lacy veins that turn brown and curl.

An adult beetle on a leaf.

Japanese beetle adult. Photo: Wisconsin DNR

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Summer Of Spongy Moth

By Andrea Diss-Torrance, Invasive Insects Program Coordinator, Madison, Andrea.DissTorrance.wisconsin.gov

Spongy moth* (formerly known as gypsy moth) populations are entering an outbreak phase in southern Wisconsin due to last year’s dry, hot weather. This pest is rising most rapidly in oak-dominated areas, especially in landscaped spaces with turf and high human activity (i.e., parks, picnic areas, campgrounds and yards). This open ground and human disturbance deter spongy moth’s predators and diseases.

Large, defoliated yard trees along road in neighborhood.

Oak trees are more vulnerable to defoliation in disturbance-heavy environments. These oak trees in Middleton, Wisconsin are facing heavy defoliation by spongy moth. Photo: Wisconsin DNR

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20 Year Anniversary Of Emerald Ash Borer Confirmation In North America

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

Five metallic green beetles against a white background.

Early photo of EAB adults taken in June 2002, prior to the insect species being identified. Photo: USDA Animal and Plant Health Inspection Service

The beginning of July marked 20 years since we received news of an unidentified beetle that turned out to be the emerald ash borer (EAB), one of North America’s greatest tree killers. On July 1, 2002, DNR forest health staff received an email from USDA Animal and Plant Health Inspection Service about this beetle being associated with declining ash in southeast Michigan:

This is to notify you that in the past few days we have responded to a report of an insect pest feeding on ash in the western suburbs of Detroit. This follows what has been a series of reports of declining ash in this area over the past couple of years. However, in the past we have not been able to associate it with any particular insect or disease. We are now seeing a boring insect emerging from the infested trees in various sites… The adult, which is emerging now, resembles the shape and size of two lined chestnut borer. It is emerald, metallic green in color and leaves a D-shaped exit hole, similar to bronze birch borer… Continue reading “20 Year Anniversary Of Emerald Ash Borer Confirmation In North America”

Leafroller Charged With Severe Oak Defoliation

By Paul Cigan, DNR Forest Health Specialist, Hayward, Paul.Cigan@wisconsin.gov or 715-416-4920; Mike Hillstrom, DNR Forest Health Specialist, Fitchburg, Michael.Hillstrom@wisconsin.gov or 608-513-7690; and Linda Williams, DNR Forest Health Specialist, Woodruff, Linda.Williams@wisconsin.gov or 920-360-0665

Oak leafrollers feed on leaves and roll/fold them with strands of silk. Photo: Wisconsin DNR

An outbreak of oak leafroller moth, Archips semiferanus, has been observed in many parts of Wisconsin this year. Oak leafrollers are native, early-season defoliators. This year they have consumed and rolled up oak leaves, giving the tree crowns a thin, yellow appearance. Continue reading “Leafroller Charged With Severe Oak Defoliation”

Lecanium Scale: A Sticky Situation

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

Lecanium scale is popping up in a few areas of Oneida and Vilas counties. These scale insects insert their mouthparts into twigs and suck the sap of the tree. They release honeydew, which can be collected by ants or may coat leaves and anything located under infested trees (i.e., yard furniture or vehicles). Sooty mold can grow on that sticky material and turn things black, so homeowners may want to rinse off the honeydew from outdoor items on a regular basis.

Brown lumps on a twig.

The brown lumps on this stem are lecanium scales. Photo: Wisconsin DNR

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