Insect

2024 Spongy Moth Spray Plans Announced

Posted on by akabelowsky

By Art Kabelowsky, DNR Outreach and Communications, Fitchburg;
Arthur.Kabelowsky@wisconsin.gov or 608-335-0167

Photo of an airplane spraying insecticide on trees at Devil's Lake State Park in Sauk County.

An airplane sprays insecticide on trees at Devil’s Lake State Park in Sauk County. / Photo Credit: Wisconsin DNR

The Wisconsin Department of Natural Resources (DNR) has finalized aerial spraying plans for its 2024 Spongy Moth Suppression Program, with maps for the six selected treatment areas available online.

The treatment sites contain high-value trees at six state parks or forests in Columbia, Marinette, Sauk and Walworth counties. A total of 928 acres will be treated with an aerial spray of “Foray” bacterial insecticide containing Bacillus thuringiensis var. kurstaki.

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Millions Of Cicadas Preparing To Emerge

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By Michael Hillstrom, Forest Health Specialist, Fitchburg;
Michael.Hillstrom@wisconsin.gov

Closeup photo of a periodical cicada, showing its black body and orange-colored wing veins and legs.

Closeup of a periodical cicada, showing its black body and orange-colored wing veins and legs. / Photo Credit: Ward Upham, Kansas State University, Bugwood.org

2024 will be a big year for periodical cicadas (Magicicada spp.).

For the first time since 1803 — when Thomas Jefferson was president — 13-year Brood XIX and 17-year Brood XIII cicadas will co-emerge in the millions.

If you want to observe this spectacle, you can see the Brood XIII cicadas in southern Wisconsin. Expect to see and hear them in June, and bring your ear protection because some of the louder choruses of males can reach 90 decibels.

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Emerald Ash Borer Spreads Through The North

Posted on by akabelowsky

By Paul Cigan, DNR Forest Health Specialist, Hayward;
https://dnr.wisconsin.gov/topic/foresthealth/staff, 715-416-4920

This winter, the spread and impact of emerald ash borer (EAB) have been confirmed in several new northern townships in previously invaded counties.

These include Marengo (Ashland County); Gordon, Hawthorne and Oakland (Douglas County); Cadott and Colburn (Chippewa County) and Balsam Lake and St. Croix Falls (in Polk County).

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Feeding Aphids Cause Spruce To Wilt

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

Have you ever wondered just how much sap can be sucked out of a tree by aphids?

Aphids insert their piercing, sucking mouthparts into needles, twigs or bark, depending on the species of aphid.

Once their mouthparts are inserted, they begin to suck sap and will excrete excess moisture as small droplets of water called honeydew.

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Time for Spongy Moth Treatment Plans

Posted on by akabelowsky

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

A photo showing numerous spongy moth egg masses on a bur oak in Walworth County.

Numerous tan-colored spongy moth egg masses on a bur oak in Walworth County. / Photo Credit: Bill McNee, Wisconsin DNR

The Wisconsin Department of Natural Resources (DNR) encourages property owners to examine their trees for spongy moth egg masses and determine whether control measures are needed this spring.

Spongy moths thrive in warm and dry weather. Even if weather conditions are more typical this spring and summer, the current spongy moth outbreak — which defoliated a state-record total of 373,000 acres of woodland last year — will likely continue and spread.

Continue reading “Time for Spongy Moth Treatment Plans” →

Woodpecker Damage On Ash Trees May Indicate Emerald Ash Borer

Posted on by akabelowsky

By Bill McNee; DNR Forest Health specialist, Oshkosh;
Bill.McNee@wisconsin.gov or 920-360-0942

Photo showing woodpecker damage on an ash tree trunk, an early sign the tree might be infested with emerald ash borer.

Woodpecker damage is an early sign an ash tree might be infested with emerald ash borer. / Photo Credit: Wisconsin DNR

The Wisconsin Department of Natural Resources (DNR) encourages property owners to watch for woodpecker damage to their ash trees this winter. If damage is found, property owners should make plans to take action in the spring.

Woodpecker damage, often called “flecking,” happens when birds peck away some of a tree’s bark to access the larvae underneath. Flecking is a common early sign that an ash tree might be infested with emerald ash borer (EAB), an invasive insect. EAB is the most damaging threat to Wisconsin trees, killing more than 99% of the untreated ash trees it infests.

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Leafminer Creates Green Bay Packers Colors On Aspen Leaves

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Photo of an aspen leaf that fell in the fall showing a “green island” due to leafminer feeding.

An aspen leaf that fell in the fall showing a “green island” due to leafminer feeding. / Photo Credit: Linda Williams, Wisconsin DNR

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

Most aspen leaves that fell this fall were a beautiful yellow gold color, but every so often some could be found that were yellow with a green strip on them. Were the aspen trees supporting the Green Bay Packers? No. The green stripe was an indication of the presence of a tiny leafmining caterpillar.

Leafminers are tiny caterpillars that live and feed within a leaf. These tiny caterpillars may produce blotch mines or serpentine mines that create lines on the leaf.

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Bronze Birch Borer Attacks Stressed Birch

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

Photo of a white birch tree with its top half dying from bronze birch borer attack.

Bronze birch borer has attacked these trees, and parts of the tree above the attack site are thin and declining. / Photo Credit: Linda Williams, Wisconsin DNR

Bronze birch borer (Agrilus anxius) is a native beetle that attacks birch trees. As adults emerge from the bark, they create small, D-shaped exit holes, similar to emerald ash borer but smaller.

Bronze birch borer attacks stressed trees, and the source of the stress can be anything from drought, flooding, defoliation or old age.

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Please Report Beech Scale Outside Of Door County

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Map showing locations of known moderate or high beech scale populations as of November 2023, in red.

Locations of known moderate or high beech scale populations as of November 2023 are shown in red. High populations are known to be widespread in Door County. / Map Credit: Bill McNee, Wisconsin DNR

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

Earlier this year, we reported that high populations of the non-native insect beech scale (Cryptococcus fagisuga) were identified for the first time in Marinette and Sheboygan counties. Since then, several more sites with moderate or high scale populations have been identified (see map).

Continue reading “Please Report Beech Scale Outside Of Door County” →